The best estimator of Eint is the kinetic energy density (Gb), which reasonably approximates the whole set of the structures as −Eint = 0.128Gb2 − 0.82Gb + 1.66  and demonstrates low dispersion. The potential and kinetic energy densities, electron density, and the d(X···X) distance behave similarly as estimators of Eint for the individual series Cl···Cl, Br···Br, and I···I. A number of the Eint(property) correlations are recommended for the practical application in the express estimates of the strength of the homo-halogen bonds.Relationships between interaction energy (E Halogen bonds play a very important role in molecular recognition and crystal engineering, synthesis of functional solid materials − type  formed upon interaction of the neutral fragment (A)nZ–Y and the halide anion X− were considered. It was shown that the Eint(property) correlations are different for each particular type of the Y···X− interaction and they are also different from Equations (1)–(4). Several Eint(property) relationships practically important for express estimates of the interaction energy were recommended for each series of these structures.Recently, the author started the project aimed to establish the Ech cycle , the halint(property) relationships are analyzed for the homo-halogen bonds of the [(A)nY–X···X–Z(B)m] type formed upon the interaction of two neutral fragments (A)nY–X and X–Z(B)m . For the first time, the Eint(property) relationships were deduced for the Cl···Cl, Br···Br, and I···I homo-XBs based on a large, statistically significant set of structures .In this work, the Eint(Vb) correlation for structures of the [(A)nZ–Y···F]− type  at the M06-2X level of theory has similar parameters as that for the MP4, CCSD, and CCSD(T) methods .int and the electron density based properties of the [(A)nZ–Y···F]− structures. Coefficients of the Eint(Vb) correlations obtained for these two basis sets are also similar . MeanwhThe Hessian matrix was calculated for all optimized structures to prove the location of correct minima. No symmetry operations were applied during the calculations. The stability test was performed and the stable solutions were achieved for all structures using the keyword STABLE(OPT). BSSE was corrected using the counterpoise (CP) method ,100. A dnY–X···X–Z(B)m]  bearing the homo-halogen bonds Cl···Cl, Br···Br, and I···I and formed upon interaction of two neutral fragments (A)nY–X and X–Z(B)m were selected as computational models . In this work, the fragment (A)nY–X (at the left side of the complex formula) corresponds to the XB donor and the fragment X–Z(B)m (at the right side of the complex formula) corresponds to the XB acceptor.For this study, structures [(A)nY–X···X–F], [(A)nY–X···X–H], and [F–X···X–Z(B)m]. In the first two series, the XB donor part is variable while the XB acceptor part is fixed with the Z(B)m group being either a strong electron acceptor (Z(B)m = F) or an electron donor (Z(B)m = H). Series of the structures with even stronger electron donor groups Z(B)m = CMe3, CHMe2, or CH3 were also calculated. However, in most of cases, secondary X···H–C interactions were found and, therefore, the individual X···X halogen bonds cannot be isolated for the analysis.For each type of halogen bonds, three series were considered, i.e., [(A)m], the XB acceptor part is variable whereas the XB donor part is fixed ((A)nY = F). Most of the attempts to calculate similar series with an electron donor group (A)nY = H failed because the σ-hole at the terminal X atom of the XB donor is not sufficiently pronounced in this case, and other interactions prevail in the resulting structures.In the third series,  type with the X···Z contact shorter the sum of van der Waals radii but with θ2 ≥ 70° and with no other weak interactions were included in the analysis since no BCPs for the X···Z contacts were found). Effect of the angle θ2 on the correlations under study is discussed in 2”.Only structures which have no other contacts shorter than the sum of van der Waals radii between the (A)nY–Cl···Cl–Z(B)m], [(A)nY–Br···Br–Z(B)m], and [(A)nY–I···I–Z(B)m] are called “large”, while the series [(A)nY–Cl···Cl–H], [(A)nY–Cl···Cl–F], [F–Cl···Cl–Z(B)m], [(A)nY–Br···Br–H], [(A)nY–Br···Br–F], [F–Br···Br–Z(B)m], [(A)nY–I···I–H], [(A)nY–I···I–F], and [F–I···I–Z(B)m] are called “small” series.Further in this work, the series [(A)int increases along the row X = Cl < Br < I . The Cl···Cl interaction is slightly weaker than the corresponding Br···Br and I···I bonds for the [(A)nY–X···X–H] and [F–X···X–Z(B)m] series (m] are the strongest ones while the XBs in the series [(A)nY–X···X–F] are typically the weakest bonds.The calculated X···X interaction energy with the BSSE correction in the whole set of the structures varies from 0.34 to −9.24 kcal/mol. All three types of halogen bonds, Cl···Cl, Br···Br, and I···I, have comparable strengths. The dispersion of E] series . The halint(property) relationships are considered for each estimator  within the whole set and various series of the structures.In the next sections, the Eb).Potential energy density at BCP  correlations reported in literature obey a linear law. The R2 values (0.80) indicate that the correlations are of rather poor quality. Meanwhile, the mean absolute deviation (MAD) for these fittings is ~0.60 kcal/mol. This value is well within the typical accuracy of the DFT methods  and this is almost three times less than the average interaction energy for this structural set .ructures A. Very cnY–X···X–Z(B)m] with the homo-halogen bonds formed upon interaction of the neutral fragment, Eint may be roughly estimated from Vb using a single formula for all X = Cl, Br, and I. This situation is very different from that found recently for the set of anionic structures [(A)nZ–Y···X]−   which could describe the whole set of structures. At least two various dependencies are clearly visible on each Eint(property) plot (ty) plot D–G.Potential energy density at BCP. The Eint(Vb) correlations for each specific type of the halogen bond are of significantly better quality than those for the whole set in terms of both R2 (0.92–0.96) and MAD  (nY–Cl···Cl–Z(B)m] and [(A)nY–Br···Br–Z(B)m] may be well approximated by a single quadratic or exponential function, the former performing slightly better with R2 = 0.92 and MAD = 0.32 kcal/mol. The [(A)nY–I···I–Z(B)m] series lies below the series with the Cl···Cl and Br···Br bonds on the −Eint(–Vb) plot.cal/mol) A. The ClKinetic energy density at BCP. The kinetic energy density behaves similarly to the potential energy density for the estimate of Eint within these series with the MAD values being only slightly worse   relationships for all series [(A)nY–Cl···Cl–Z(B)m], [(A)nY–Br···Br–Z(B)m] and [(A)nY–I···I–Z(B)m] have similar parameters despite the application of different basis sets . Meanwhile, the Eint(Vb) relationship for the iodine halogen bonds is quite different from those for the Cl···Cl and Br···Br structures. Thus, the application of Gb as an estimator of Eint is preferable over Vb also from this point of view.cal/mol) B. HoweveElectron density at BCP. The Eint(ρb) relationships for these series are similar to Eint(Vb) and Eint(Gb) nY–Br···Br–Z(B)m] and [(A)nY–I···I–Z(B)m] may be approximated by a single function , while the fitting for the [(A)nY–Cl···Cl–Z(B)m] series has quite different parameters.Eint(Gb) C. In conLaplacian and curvature of electron density distribution at BCP. Both Eint(∇2ρb) and Eint relationships for these series have similar features and are described by either quadratic or exponential function  relationships demonstrate different behavior for the Cl···Cl and Br···Br series, on one side, and for the I···I series, on the other side . For the Br···Br series, the Eint(Hb) function is not well-defined. Finally, for the I···I structures, −Eint increases with the decrease of Hb. The −Eint(Hb) relationship is nearly linear with R2 = 0.93 and MAD = 0.42 kcal/mol and may be used for the estimate of Eint for this type of halogen bonds.her side F. For thInternuclear distance d(X···X). The −Eint(d(X···X)) dependencies are exponential with rather different parameters for the Cl···Cl, Br···Br, and, in particular, I···I structures  plots. The best Eint(Gb) approximation was found for the [F–X···X–Z(B)m] series with R2 = 0.86 and MAD = 0.44 kcal/mol (int(ρb) function also reasonably describes each of the pairs “[(A)nY–Br···Br–H] + [(A)nY–I···I–H] and “[(A)nY–Br···Br–F] + [(A)nY–I···I–F] (int(property) relationships significantly depend on the nature of the interacting atoms X.Typically, there are no statistically meaningful trends describing these series . Severalkcal/mol A. The EiI···I–F] B but thePotential energy density at BCP. The Eint(Vb) relationship for each of nine “small” series may be reasonably approximated by a linear function. The quadratic fitting is noticeably better than the linear one only for the [F–Cl···Cl–Z(B)m], [(A)nY–I···I–H], and [(A)nY–I···I–F] series (] series A–C. The int(−Vb) relationships for the [F–Cl···Cl–Z(B)m], [F–Br···Br–Z(B)m], and [F–I···I–Z(B)m] series are significantly higher than for the other series, whereas those for the [(A)nY–Cl···Cl–F], [(A)nY–Br···Br–F], and [(A)nY–I···I–F] structures are the lowest.First, the slope and negative interception of the −E2. However, the MAD values for the  “small” series  are significantly lower than for the corresponding “large” series . The estimate of Eint for the structures [F–Br···Br–Z(B)m] and [F–I···I–Z(B)m] is preferable using equations for the “large” series because both MAD and R2 parameters are worse for these “small” series than for the corresponding “large” ones.Second, quality of the dependencies for the “small” series is usually worse than for the “large” ones in terms of RnY–Cl···Cl–H], is described by an equation similar to the EML formula (Eint = 0.47Vb + 0.27). Equations (3)–(5) obtained for the halogen bonds of the X···D type  [nY–X···X–Z(B)m] type discussed in this work (except the same [(A)nY–Cl···Cl–H] series).Third, among all “small” series, only one, , [(A)nY–Cl···Cl–F] and [F–Cl···Cl–Z(B)m]  relationship is of the same type for [(A)nY–Br···Br–H] and [(A)nY–Br···Br–F] m] and as a linear function for the I...I structures (int(Hb) dependencies for the “small” series is worse than for the other estimators.l–Z(B)m] D althoug···Br–F] E. Howeveructures F. The quOther estimators. The main features of the Eint(Gb), Eint(ρb), Eint(∇2ρb), Eint, and Eint(d(X···X)) relationships for the “small” series are similar to the corresponding Eint(Vb) dependencies (m] particularly poor.ndencies . Laplacir) over IAS (r ∈ IAS) may be a better estimator of Eint than the potential energy density at BCP (Vb). This result was obtained for a set of 50 structures with very different types of non-covalent interactions. Here, the quality of this estimator was verified for structures of the [(A)nY–Cl···Cl–Z(B)m] type. The calculations indicated that the IAS integral of electronic virial field behaves similarly as Vb for the [(A)nY–Cl···Cl–H] and [(A)nY–Cl···Cl–F] series  and relatively high MAD . Correspondingly, the Eint(nY–Cl···Cl–Z(B)m] is also significantly worse than the Eint(Vb) relationship with R2 = 0.89 vs. 0.96 and MAD = 0.28 vs. 0.18 kcal/mol.Recently, Romanova, Lyssenko, and Ananyev  reported compare A. Howeveb against nY–Cl···Cl–H] (R2 = 0.99), a quite good relationship for [(A)nY–Cl···Cl–F] (R2 = 0.96) but a poor dependence for [F–Cl···Cl–Z(B)m] (R2 = 0.75)  B. Thus, 1···Z contact in structures [(A)nY–X1···X2–Z(B)m] included in the analysis, some of them have the angleX1X2Z (θ2) lower than 90°. This may point out some interaction between the atoms X1 and Z. To verify if this possible interaction affects the Eint(property) dependencies, all structures were divided into three groups, i.e., those with θ2 ≥ 90°, 80° ≤ θ2 < 90°, and 70° ≤ θ2 < 80°. In the second and third groups, structures with the X1···Z distance shorter than the sum of van der Walls radii were also separated from those with the X1···Z distance longer than this sum.Although no BCP was found for the Xint(Vb) dependencies for all these groups of structures are shown in 2 and the X1···Z distance. If considering only structures with θ2 ≥ 90°, R2 and MAD values are similar to those for the complete structural series except the Br···Br structures  on the Eint(Vb) dependencies. Similar results were obtained for all other estimators.The E compare D. In theint(property) correlations were established and analyzed for the first time for the large statistically significant sets of the homo-halogen bonds Cl···Cl, Br···Br, and I···I formed upon interaction of two neutral fragments at the M06-2X/6-31+G* (the Cl···Cl and Br···Br bonds) and M06-2X/DZP (the I···I bond) levels of theory. Electron density, its Laplacian, curvature of the electron density distribution, potential, kinetic, and total energy densities at BCP, integral of electronic virial over IAS and the d(X···X) internuclear distance were examined as estimators of the interaction energy. The correlations obtained in this work have a significant practical potential since they lead to interaction energies of the entire classes of the halogen bonds with the electron density distribution or even only the d(X···X) internuclear distance being in the hands. This is particularly important for the systems with multiple intermolecular non-covalent interactions or those bearing intramolecular XBs because a direct determination or calculation of Eint for such systems is an extremely difficult or often even impossible task. The following conclusions can be made.In this work, the Eint = 0.128Gb2 − 0.82Gb + 1.66 with R2 = 0.91 and MAD = 0.39 kcal/mol. For other estimators, no reasonable single correlation was found for the whole structural set.First, the whole set of structures can be reasonably approximated by a single quadratic function −Eint(Vb), Eint(Gb), Eint(ρb), Eint, and Eint(d(X···X)) relationships, all of them being nonlinear . Quality of these relationships is better for the Cl···Cl structures compared to the Br···Br and I···I ones. Total energy density behaves well only for the I···I structures while the −Eint(Hb) function is not well-defined for the Br···Br structures. Laplacian ∇2ρb works well for the Cl···Cl and Br···Br series but not for the I···I one.Second, each of the series Cl···Cl, Br···Br, and I···I can be well described individually by the Eint due to lower dispersion of the Eint(Gb) functions.Third, the kinetic energy density at BCP can be recommended as the best estimator of EnY–X···X–H], [(A)nY–X···X–F], and [F–X···X–Z(B)m].Fourth, typically, there are no statistically meaningful trends describing the series [(A)2 but it is better in terms of MAD (with exception of the [F–Br···Br–Z(B)m] and [F–I···I–Z(B)m] structures).Fifth, quality of correlations for the “small” series is usually worse than that for the “large” series Cl···Cl, Br···Br, and I···I in terms of Rint(Vb) and Eint(Gb) relationships are close to Equations (1)–(5) only for the [(A)nY–Cl···Cl–H] structures. Additionally, the Eint(property) correlations obtained here for the Cl···Cl and Br···Br bonds are significantly different from those found previously for the Cl···Cl− and Br···Br− interactions between the neutral fragments (A)nY–Hal and the halide anion Hal− [Sixth, the obtained here Eion Hal− . This onint estimator at least for the Cl···Cl bond.Seventh, the IAS integral of electronic virial Eighth, the BSSE effect is insignificant for the Cl···Cl structures but becomes important for the I···I and, in particular, Br···Br structures.int(property) relationships recommended for the Cl···Cl, Br···Br, and I···I interactions are given in i) establishment of the Eint(property) relationships for the hetero-halogen bonds Hal1···Hal2  and other types of the non-covalent interactions  and (ii) analysis of the effect of computational method, basis set and effective core pseudopotentials on these correlations. The corresponding studies are currently underway.The E


The title compound, the potassium salt of a benzothiazol(methylsulfanyl)pyriminidine, was obtained in a reaction designed to deliver a neutral 2-pyrimidylbenzothiazole. It crystallized with two independent molecular units in the asymmetric unit. +·C18H14N5O2S3−·C3H7NO·0.5H2O, was obtained in a reaction designed to deliver a neutral 2-pyrimidylbenzothiazole. The anion is deprotonated at the sulfonamide nitrogen. The asymmetric unit of the title compound contains two potassium cations, two anions, two molecules of DMF and one of water. The anions display some conformational differences but each contains an intramolecular N—H⋯Nbenzothiazole hydrogen bond. The potassium ions both display a highly irregular six-coordination, different for each potassium ion. The anions, together with the DMF and water molecules, are linked by four classical hydrogen bonds to form chains parallel to the b-axis direction.The title compound, K The atom K2 is coordinated by N2′, N5′ and both DMF oxygen atoms within the asymmetric unit, plus O2 at  and O1 at . The angles subtended by the chelating anions via N2/N5 are particularly narrow. The bridging nature of O92 is shown in Fig. 3The potassium ions both display a highly irregular six-coordination; all K—N and K—O contacts Table 1 are < 2.S(6) ring motif. The anions display some differences in conformation; the angle between the benzothiazole ring (seven atoms) and the pyrimidine ring plus immediate substituents (ten atoms) is 20.56 (5)° for anion 1 (unprimed atoms) but 42.20 (2)° for anion 2 (primed atoms). Comparing the torsion angles in Table 1cf. torsion angle C10—N5—S3—C13 is 62.49 (11)°, and 65.28 (11)° in the non-inverted system.Each anion displays an intramolecular hydrogen bond -6-(methylsulfanyl)pyrimidin-2-yl](phenylsulfonyl)azanide dimethylformamide monosolvate hemihydrate (5):d]thiazole-2-yl)-3,3-bis(methylthio)acrylonitrile (2) (0.01 mol) was added to a stirred solution of the N-(diaminomethylene)benzenesulfonamide (3) (0.01 mol) in dry dioxane (20 ml) containing potassium hydroxide (0.01 mol); the reaction mixture was refluxed for 2 h. After completion of the reaction (TLC), the solid precipitate was filtered off, and then recrystallized from DMF/H2O to give colourless block-like crystals of compound 5, the potassium salt of compound 4, in 75% yield (m.p. = 517 K). IR : ν 3431 and 3874 . 1H NMR : δ 2.19 , 7.32–7.39 , 7.46 , 7.83–7.85 , 7.92 , 8.01 , 8.49 , 11.50 .The reaction pathway is illustrated in Fig. 1Uiso(H) = 1.5Ueq(C-methyl)], and allowed to rotate but not to tip (AFIX 137). Other hydrogen atoms were included using a riding model starting from calculated positions: C—Haromatic = 0.95 Å with Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989019002275/su5477sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989019002275/su5477Isup2.hklStructure factors: contains datablock(s) I. DOI: 1896740CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The dihedral angles between the aromatic rings are 31.99 (3) and 9.17 (5)° for 1 and 2, respectively. Compound 1 features an intramolecular bifurcated N—H⋯ link due to the presence of the ortho-Cl atom on the benzene ring, whereas 2 features an intramolecular N—H⋯O hydrogen bond. In the crystal of 1, inversion dimers linked by pairs of N—H⋯S hydrogen bonds generate R22(8) loops. The extended structure of 2 features the same motif but an additional weak C—H⋯S interaction links the inversion dimers into [100] double columns. Hirshfeld surface analyses indicate that the most important contributors towards the crystal packing are H⋯H (26.6%), S⋯H/H.·S (13.8%) and Cl⋯H/H⋯Cl (9.5%) contacts for 1 and H⋯H (19.7%), C⋯H/H⋯C (14.8%) and Br⋯H/H⋯Br (12.4%) contacts for 2.The title compounds, C The biological activities of these compounds were previously reported by Khan et al.  Å] benzoyl ring linked to a ortho-chloro-substituted phenyl ring [C—Cl = 1.7387 (14) Å] in while in 2  Å] benzoyl ring is linked to a para-bromo-substituted phenyl ring [C—Br = 1.8991 (17) Å] via a thiourea (S1/N1/N2/C8) linkage. The benzoyl (O1/C1–C7) and phenyl rings (C9–C14) are arranged about the thiourea moiety in an anti fashion having torsion angles C8—N1—C7—C6 = −170.22 (13) and C9—N2—C8—S1 = 4.5 (2)° in compound 1, with corresponding values of −176.01 (16) and 3.8 (3)°, respectively, in compound 2. The dihedral angles between the phenyl rings are 31.99 (3) and 9.17 (5)° in 1 and 2, respectively. Compound 1 features an intramoleclar bifurcated N—H⋯ hydrogen bond (Table 1ortho-Cl atom whereas 2 has an intramolecular N—H⋯O link (Table 2S(6) ring. These intramolecular hydrogen bonds may be responsible for the anti arrangement of the aromatic rings about the thiourea linker.Compound 1 Fig. 1 is compo 2 Fig. 2, a para-d Table 1 due to tk Table 2. Both st1, inversion dimers linked by pairwise N1—H1A⋯S1 hydrogen bonds phenyl]carbamothioyl}-3-methylbenzamide (CCDC deposition No. 1840069) and 4-chloro-N-{[4-chloro-3-(trifluoromethyl)phenyl]carbamothioyl}benzamide (CCDC 1587395)  for compounds related to 1 and 2, Hirshfeld surfaces   (26.6%) contacts, followed by S⋯H/H⋯S (13.8%), Cl⋯H/H⋯Cl (9.5%) O⋯H/H⋯O (6.7%), F⋯H/H⋯F (6.6%), Cl⋯F/F⋯Cl (3.7%) and F⋯C/C⋯F (3.1%) interactions. In compound 2, H⋯H (19.7%)  are the most significant, followed by C⋯H/H⋯C (14.8%), S⋯H/H⋯S (12.6%), Br⋯H/H⋯Br (12.4%), C⋯C (9.9%) and O⋯N/N⋯O (7.9%) interactions.In order to further analyse the close contacts and intermolecular interactions in the crystals of x) Fig. 5 and two-x) Fig. 5 and 7 ▸ 1 and 2 were synthesized by adopting a literature procedure  or 4-bromophenyl aniline (for 2) were added to the mixture and refluxed at 343 K. Hydrochloric acid  was added and the solution was filtered to obtain the desired products: 1 in 69% yield and 2 in 80% yield. For recrystallization, compound 1 was dissolved in a mixture of dichloromethane and methanol (1:1) while compound 2 was dissolved in dichloromethane and left for slow evaporation at room temperature to obtain colourless prisms of 1 and colourless plates of 2Compounds 1, the N-bound H atoms were located in difference-Fourier maps and their positions were freely refined; in 2, the N-bound H atoms were located in difference-Fourier maps and refined as riding atoms in their as-found relative positions. The constraint Uiso(H) = 1.2Ueq(carrier) was applied in all cases.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989019008569/hb7804sup1.cifCrystal structure: contains datablock(s) global, 1, 2. DOI: Click here for additional data file.10.1107/S2056989019008569/hb78041sup4.cmlSupporting information file. DOI: 10.1107/S2056989019008569/hb78041sup4.hklStructure factors: contains datablock(s) 1. DOI: 10.1107/S2056989019008569/hb78042sup3.hklStructure factors: contains datablock(s) 2. DOI: Click here for additional data file.10.1107/S2056989019008569/hb78042sup5.cmlSupporting information file. DOI: 1923234, 1923233CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, extensive hydrogen bonding, with the dimethylammonium cation and the water molecule linking the complex anions, results in the formation of a supramolecular framework.The title complex was synthesized sonochemically. The ligand was formed  3)2NH2][Cr(C6H10NO4)2Cl]·H2O, was synthesized sonochemically. The complex anion consists of a chromium(II) ion ligated by two 3-carboxy-2-(dimethylamino)propanoate anions. They coordinate in a bidentate manner, with a carboxylate oxygen atom and the nitrogen atom cis to each other in the equatorial plane, while the apical position is occupied by a Cl− ion. Hence, the chromium(II) ion is five-coordinate with a quasi-ideal square-pyramidal geometry; τ5 parameter = 0.01. The complex crystallizes as a monohydrate and in the crystal, the water molecule and the dimethylammonium counter-ion link the complex cations via N—H⋯O, N—H⋯Cl, Owater—H⋯O, O—H⋯Owater and O—H⋯O hydrogen bonds, forming a supramolecular framework. There are also a number of C—H⋯O hydrogen bonds present that reinforce the framework structure. The crystal studied was refined as a racemic twin.The title complex, [(CH The chloride anion, Cl1, occupies the apical position. The five-coordinate chromium ion is displaced by 0.3469 (7) Å from the mean plane through atoms O1, N1, O5 and N2. The equatorial Cu—O bond lengths are Cr1—O1 = 1.960 (5) Å and Cr1—O5 = 1.954 (5) Å, while the equatorial Cu—N bond lengths are slightly longer viz. Cr1—N1 = 2.025 (5) Å and Cr1—N2 = 2.030 (5) Å. The axial Cr1—Cl1 bond length is 2.5301 (16) Å. The C—C, C—O, and C—N bond lengths of the ligands are close to those reported for similar compounds  to 100.88 (16)° and from 159.6 (2) to 160.3 (2)°, respectively. This leads to a quasi-ideal square-pyramidal geometry for atom Cr1 with a τ5 parameter of 0.01 -dimethyl 3-(diphenylphosphino)-N,N-dimethylaspartate]dichloropalladium(II)  in 10 ml of water was added with magnetic stirring for a further 30 min. The mixture was then put in an ultrasonic bath  for 2h. The solution was then left to evaporate slowly and blue prismatic crystals were collected after two months.A mixture of fumaric acid  and dimethylamine hydrochloride (0.09 ml) dissolved in 20 ml methanol was stirred for 1 h. Chromium(II) acetate dihydrate [CrUiso(H) = 1.5Ueq(O). All other H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms: O—H = 0.82 Å, N—H = 0.89 Å, C—H = 0.96–0.99 Å with Uiso(H) = 1.5Ueq and 1.2Ueq for other H atoms.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989019004717/su5493sup1.cifCrystal structure: contains datablock(s) I, Global. DOI: 10.1107/S2056989019004717/su5493Isup2.hklStructure factors: contains datablock(s) I. DOI: 1892216CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The title compound is a host–guest complex of the tris-urea receptor, 3-(4-nitrophenyl)-1,1-bis{2-[3-(4-nitrophenyl)ureido]ethyl}urea, encapsulating a hydrogen-bonded chain of dihydrogen phosphate anions. 25H25N9O9·C16H36N+·H2PO4− (I) or (C25H25N9O9)·(n-Bu4N+)·(H2PO4−) (systematic name: 3-(4-nitrophenyl)-1,1-bis{2-[3-(4-nitrophenyl)ureido]ethyl}urea tetrabutylammonium dihydrogen phosphate), comprises a tris-urea receptor (R), a dihydrogen phosphate anion and a tetra-n-butylammonium cation. It crystallizes with two independent formula units in the asymmetric unit. The conformations of the two tris-urea receptors are stabilized by N—H⋯O and C—H⋯O intramolecular hydrogen bonds. Each dihydrogen phosphate anion has two O—H⋯O intermolecular hydrogen-bonding interactions with the other dihydrogen phosphate anion. Inversion-related di-anion units are linked by further O—H⋯O hydrogen bonds, forming a chain propagating along the a-axis direction. Each dihydrogen phosphate anion makes a total of four N—H⋯O(H2PO4−) hydrogen bonds with two ureido subunits from two different tris-urea receptors, hence each tris-urea receptor provides the two ureido subunits for the encapsulation of the H2PO4− hydrogen-bonded chain. There are numerous intermolecular C—H⋯O hydrogen bonds present involving both receptor molecules and the tetra-n-butylammonium cations, so forming a supramolecular three-dimensional structure. One of the butyl groups and one of the nitro groups are disordered over two positions of equal occupancy.The title compound, C Interestingly, a one-dimensional hydrogen-bonded polymeric structure is formed via hydrogen bonds between dihydrogen phosphate anions, and this anionic polymer is surrounded by and linked to the tris-urea receptors through ureido N—H⋯O hydrogen bonds.Anions play an important role in many chemical, catalysis, environmental and biological systems (Sessler R1 and R2) and the dihydrogen phosphate anions (P1 and P2) are illustrated in Fig. 1N⋯O7 in R1 and N17—H17N⋯O16 in R2), each forming an S(9) ring motif,. Four intramolecular C—H⋯O hydrogen bonds are also present in receptor R1 and three in R2 . The urea subunits N5/N6 in R1 and N11/N12 in R2 are orientated towards the dihydrogen phosphate ions (P1 and P2) forming a 2:2 adduct via N—H⋯O hydrogen bonds with anion P1 and enclosing trans to the C=O group across the respective C—N bond. Anions P1 and P2 interact with each other via two O—H⋯O hydrogen bonds (O20—H20O⋯O24 and O23—H23O⋯O22), enclosing an R1 and from 6.87 (14) to 13.82 (14)° in R2. The dihedral angle between the nitro group and the benzene ring to which it is attached also vary, from 7.1 (3) to 13.4 (4)° in R1 and from 8.3 (4) to 16.7 (7)° in R2.The title compound crystallizes with two independent formula units in the asymmetric unit. The molecular structure of the two tris-urea receptors , that are linked by O—H⋯O hydrogen bonds O20—H20O⋯O24 and O23—H23O⋯O22, are further linked to inversion-related anions via hydrogen bonds O21—H21O⋯O19i and O25—H25O⋯O26ii amine (tren). One of these compounds, tetra-n-butylammonium tris(2-(N-perfluorophenylureaylato)ethyl)amine dihydrogen phosphate dimethylformamide monosolvate, encapsulates a dimer of H2PO4− anions forming a pseudo-dimeric cage via sixteen hydrogen bonds and two weak anion⋯π interactions ]tris(N′-phenylurea) tetra-n-butylammonium dihydrogen phosphate  bis(dihydrogen phosphate) -1-(4-nitrophenyl)-3-{2-[3-(4-nitrophenyl)ureido]cyclohexyl}urea acetonitrile monosolvate –2.21 (2) Å in the title compound. The O—H⋯O hydrogen bonds involving the H2PO4− anions are also very similar: 1.62 (3) and 1.63 (4) Å in DASNUH, while they vary from 1.59 (2) to 1.66 (2) Å in the title complex.Chiral anion receptors with two enantiomeric forms Synthesis of 3-(4-nitrophenyl)-1,1-bis{2-[3-(4-nitrophenyl)ureido]ethyl}urea (R): In a 250 ml round-bottom flask, diethylenetriamine  dissolved in 100 ml of dry CH2Cl2 was added dropwise under vigorous stirring to a solution of 20 ml of dry CH2Cl2 containing p-nitrobenzene isocyanate . Subsequently, the reaction mixture was allowed to reflux for 24 h. A yellowish solid was collected by filtration and washed using sequentially CH2Cl2 (3 × 70 ml), a solvent mixture  and diethyl ether (3 × 70 ml). The solid was then dried in vacuo overnight to afford the receptor R as a light-brown powder . FT–IR : 3339, 1679, 1606, 1559, 1501, 1330. 1H NMR  in ppm: δ = 9.42 , 9.23 , 8.10 , 7.76 , 7.59 , 6.60 , 3.51 . 13C NMR  in ppm: δ = 154.99, 154.67, 147.34, 146.94, 140.72, 140.48, 125.09, 124.70, 118.13, 116.95, 46.63, 40.15–38.89, 38.19. HRMS (ESI+): calculated for C25H25N9O9Na [M + Na]+ 618.1673 found 618.1678.Synthesis of the title complex (I) Tetra-n-butylammonium dihydrogen phosphate (1.68 mmol) was added to 5 ml of a DMF solution of R (0.168 mmol) and the mixture was stirred for 2 h. After filtration the solution was left to evaporate slowly and yielded colourless prismatic crystals of the title complex within three weeks.Uiso(H) = 1.5Ueq(O) and 1.2Ueq(N). The C-bound H atoms were positioned geometrically and refined using a riding model: C—H = 0.95–0.99 Å, with Uiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms.Crystal data, data collection and structure refinement details are summarized in Table 2A/C79B, C80A/C80B, C81A/C81B, and C82A/C82B atoms of the disordered fragment were restrained to be similar  is disordered over two positions with equal occupancies. The C—C distances were refined with the restraint of 1.515 (4) Å. The displacement parameters of the C7910.1107/S2056989019001336/kq2020sup1.cifCrystal structure: contains datablock(s) I, Global. DOI: 10.1107/S2056989019001336/kq2020Isup3.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019001336/kq2020Isup3.cmlSupporting information file. DOI: 1893140CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, molecules are linked  15H12F3NO3, crystallizes with one molecule in the asymmetric unit. The mean planes of the two phenyl rings of the Schiff base moiety, bearing the OH groups and the imine group, respectively, are inclined to each other by 4.91 (1)°. In the crystal, molecules are linked via pairs of bifurcated O—H⋯O hydrogen bonds between the phenol OH groups, forming inversion dimers with an R12(5) ring motif. The structure exhibits also intramolecular O—H⋯N and C—H⋯F hydrogen-bonding interactions. Hirshfeld surfaces analysis and two-dimensional fingerprint plots were applied to quantify the intermolecular interactions. The three F atoms of the trifluoromethyl group are disordered over two sets of sites, with occupancy factors of 0.578 (8) and 0.422 (8). The crystal studied was refined as an inversion twinThe title compound, C The synthesis involves an aromatic amine and an aldehyde -3-({[3-methoxy-5-(trifluoromethyl)phenyl]imino}methyl)benzene-1,2-diol, was obtained in crystalline form from the reaction of 2,3-dihydroxybenzaldehyde with 3-methoxy-5-(trifluoromethyl)aniline.In general, Schiff bases display two possible tautomeric forms, T1(C1—C6—C7—N1) and T2(C7—N1—C8—C9). The respective values of = 2.0 (10) and −5.5 (11)° indicate that the molecule is not planar  ring motif, characteristic of o-hydroxysalicylidene systems. Other intramolecular hydrogen bonding interactions involve the disordered –CF3 group and adjacent aromatic H atoms bonded to C9 and C11  Å] and the single bond character of O1—C2 [1.368 (6) Å] in the phenol–imine tautomer. These values and other bond lengths and angles Table 1 are in g1 Table 2. As a reBetween adjacent molecules there are bifurcated intermolecular O1—H⋯ hydrogen bonds with an if Fig. 2, leadinget al., 2016Z)-1-phenyl-N-[3-(trifluoromethyl)phenyl]methanimine skeleton yielded eight matches. Distinctive bond lengths  in the Schiff base structure are the same within standard uncertainties as those of the corresponding bond lengths in the structures of 4N--3-methoxysalicylaldimine -3-{[3-(trifluoromethyl)phenylimino]methyl}benzene-1,2-diol -5-(trifluoromethyl)aniline -2-methyl-6-[3-(trifluoromethyl)-phenyliminomethyl]phenol -2-[(4-chlorophenyl)iminomethyl]-4-(trifluoromethoxy)phenol -4-methyl-2-[3-(trifluoromethyl)phenyliminomethyl]phenol  plot with de and di for the title compound is shown in Fig. 3de = di = 1.5 Å; Fig. 4Hirshfeld surface analysis of the title compound was performed utilizing the The title compound was prepared by refluxing mixed solutions of 2,3-dihydroxybenzaldehyde  in ethanol (15 ml) and 3-methoxy-5-(trifluoromethyl)aniline  in ethanol (15 ml). The reaction mixture was stirred for 5 h under reflux. Single crystals of the title compound for X-ray analysis were obtained by slow evaporation of an ethanol solution .Uiso(H) set to 1.2–1.5Ueq(C), and with O—H = 0.82 Å and Uiso(H) = 1.5Ueq(O). The three F atoms of the trifluoromethyl group are disordered over two sets of sites, with occupancy factors of 0.578 (8) for F atoms with suffix A and 0.422 (8) for those with suffix B  I, global. DOI: 10.1107/S2056989019003220/wm5488Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019003220/wm5488Isup3.cmlSupporting information file. DOI: 1892713CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


L as the dihedral angle between the pyridyl rings is 78.37 (5)°. Linear supramolecular chains are found in the crystal mediated by weak carbonyl-C=O⋯π(triazolyl) interactions.The title molecule adopts the shape of the letter  16H15N5O2, adopts the shape of the letter L with the dihedral angle between the outer pyridyl rings being 78.37 (5)°; the dihedral angles between the central pyrazolyl ring (r.m.s. deviation = 0.0023 Å) and the methylene-bound pyridyl and methyoxypyridyl rings are 77.68 (5) and 7.84 (10)°, respectively. Intramolecular amide-N—H⋯N(pyrazolyl) and pyridyl-C—H⋯O(amide) interactions are evident and these preclude the participation of the amide-N—H and O atoms in intermolecular interactions. The most notable feature of the molecular packing is the formation of linear supramolecular chains aligned along the b-axis direction mediated by weak carbonyl-C=O⋯π(triazolyl) interactions. An analysis of the calculated Hirshfeld surfaces point to the importance of H⋯H (46.4%), C⋯H (22.4%), O⋯H (11.9%) and N⋯H (11.1%) contacts in the crystal.The title compound, C The synthesis of amide bonds utilizing T3P offers high yields, low epimerization and avoids the use of hazardous additives such as explosive hydroxybenzotriazole (HOBt). Further, reactions occur with high yields and lead to the easy removal of the by-products with a simple work-up, overall resulting in the formation of high-quality product. In addition, it is noted that the T3P reagent is non-toxic and non-allergenic a, these lead to linear supramolecular chains aligned along the b-axis direction. The supramolecular chains pack without specific interactions between them, Fig. 2b.The molecular packing of (I)et al., 2016dnorm in Fig. 3B, pyridyl-N3 and pyridyl-H5 atoms are indicative of short interatomic N⋯H/H⋯N contacts s Table 2. In addis Table 2 are highs Table 3 between a, and those delineated into H⋯H, N⋯H/H⋯N, O⋯H/H⋯O, C⋯H/H⋯C and C⋯C contacts de + di ∼ 2.5 Å and 2.7 Å, respectively, in the corresponding delineated fingerprint plots Fig. 5c and e. The pair of spikes with the tips at de + di ∼ 2.6 Å and the regions of green points aligned in the fingerprint plot delineated into N⋯H/H⋯N contacts, Fig. 5d, are indicative of short N⋯H interatomic contacts  although the contribution from these contacts is relatively small. The notable percentage contributions from O⋯N/N⋯O and C⋯O/O⋯C contacts to the Hirshfeld surfaces s Table 2. In the ms Fig. 3b althous Table 2 in the cet al., 2016The 1,3 N—C and C—C(=O)N(H)—C substitution pattern observed in (I)H-Pyrazole-4-carboxylic acid (0.0446 mol) was treated with diisopropylethyl amine (0.0669 mol) and 1-propane phosphonic acid (T3P) (0.0669 mol) in dimethyl formamide (10 ml) at 273 K for 15 min. Then, 6-methoxypyridin-2-amine (0.0490 mol) was added at 273 K. The reaction mixture was heated at 353 K for 3 h. After completion of the reaction, the product was extracted with ethyl acetate and the excess solvent was removed under vacuum. The product was recrystallized using methanol as solvent to yield 1-(6-methoxypyridin-2-ylmethyl)-1H-pyrazole-4-carboxylic acid. This product (0.0246 mol) and 2-(chloromethyl)pyridine (0.0295 mol) were dissolved in acetone (10 ml), potassium carbonate (0.0369) was added and the reaction mixture was heated at 329 K for 5 h. After completion of the reaction, the product was extracted with ethyl acetate twice (5 ml) and the extract was concentrated under vacuum. The product was washed with diethyl ether (3 ml) and recrystallized from methanol solution to obtain the title compound, (I)1Uiso(H) set to 1.2–1.5Ueq(C). The N-bound H atoms was refined with a distance restraint of 0.86±0.01 Å, and with Uiso(H) = 1.2Ueq(N).Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S2056989018011477/hb7767sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989018011477/hb7767Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018011477/hb7767Isup3.cmlSupporting information file. DOI: 1861657CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Supramolecular chains arise in the crystal as a result of O—H⋯O and N—H⋯O hydrogen bonding.The  17H17F6N2O+·C2ClF2O3− quinolin-4-yl](hydroxy)methyl}piperidin-1-ium chlorodifluoroacetate), the cation, which is protonated at the piperidine N atom, has the shape of the letter, L, with the piperidin-1-ium group being approximately orthogonal to the quinolinyl residue [the Cq—Cm—Cm–Na  torsion angle is 177.79 (18)°]. An intramolecular, charge-assisted ammonium-N—H⋯O(hydroxyl) hydrogen bond ensures the hydroxy-O and ammonium-N atoms lie to the same side of the molecule [Oh—Cm—Cm—Na (h = hydroxyl) = −59.7 (2)°]. In the crystal, charge-assisted hydroxyl-O—H⋯O−(carboxylate) and ammonium-N+—H⋯O−(carboxylate) hydrogen bonds generate a supramolecular chain along [010]; the chain is consolidated by C—H⋯O interactions. Links between chains to form supramolecular layers are of the type C—Cl⋯π(quinolinyl-C6) and the layers thus formed stack along the a-axis direction without directional interactions between them. The analysis of the calculated Hirshfeld surface points to the dominance of F⋯H contacts to the surface (40.8%) with significant contributions from F⋯F (10.5%) and C⋯F (7.0%) contacts.In the racemic title molecular salt, C R*,S*)-quinolin-4-yl](hydroxymethyl)piperidin-1-ium chloride is an anti-malarial drug, being effective against the causative agent, Plasmodium falciparum . In a continuation of structural studies of Mefloquine derivatives quinolin-4-yl]-piperidin-2-ylmethanol). This arises when the racemic compound is reacted with HCl: the resulting salt, [-erythro-mefloquinium] isomer. However, it should be noted that the centrosymmetric unit cell has equal numbers of the other S-,R- enantiomer, indicating that no resolution occurred during the crystallization experiment as has been observed in some of the earlier studies . The pattern of hydrogen-bonding interactions involving the ammonium-N—H H atoms (see Supramolecular features) provides confirmation of protonation at the N2 atom during crystallization and, therefore, the formation of a piperidin-1-ium cation. At the same time, delocalization of the π-electron density over the carboxylate residue is confirmed by the equivalence of the C18—O2, O3 bond lengths, i.e. 2 × 1.238 (3) Å.The ions comprising the asymmetric unit of (I)cf. with that of 177.79 (18)° for C3—C12—C13—N2. The latter angle indicates the piperidin-1-ium residue is almost perpendicular to the quinolinyl residue with the methylene-C17 group orientated towards the fused-ring system as seen in the gauche C3—C12—C13—C17 torsion angle of −60.7 (3)°. The observed conformation, whereby the hydroxy-O and ammonium-N atoms lie to the same side of the molecule [the O1—C12—C13—N2 torsion angle is −59.7 (2)°], is stabilized by an intramolecular, charge-assisted ammonium-N2+—H⋯O1(hydroxyl) hydrogen bond, Table 1L.The quinolinyl residue is not strictly planar with the r.m.s. deviation for the ten fitted non-H atoms being 0.0399 Å. This is also reflected in the dihedral angle formed between the  and (C4–C9) rings of 3.95 (15) Å. This aspect of the structure notwithstanding, the hydroxyl-O and ammonium-N atoms lie to opposite sides of the plane through the quinolinyl residue. This is seen in the value of the C2—C3—C12—O1 torsion angle of −20.3 (3)° 2C2 plane [r.m.s. deviation = 0.0089 Å], with the O2—C18—C19—Cl1 torsion angle being −93.3 (2)°, and the F7 and F8 atoms lying to the other side, the O2—C18—C19—F7, F8 torsion angles = 28.8 (3) and 146.3 (2)°, respectively. The conformation of the CClF2 residue in (I)et al., 1996e.g. with mono-protonated 1,4-diazabicyclo[2.2.2]octane (dabco), i.e. 4-aza-1-azoniabicyclo[2.2.2]octane, for which three independent ion pairs comprise the asymmetric unit −(carboxylate) and ammonium-N+—H⋯O−(carboxylate) hydrogen bonding features prominently in the molecular packing of (I)b-axis direction, Fig. 1a and Table 1+—H⋯O−(carboxylate) hydrogen bonds link two cations and two anions about a centre of inversion to form eight-membered {⋯HNH⋯O}2 synthons, Fig. 2b. These are linked into a supramolecular chain via hydroxyl-O—H⋯O−(carboxylate) hydrogen bonding, which leads to 18-membered {⋯OCO⋯HNC2OH}2 synthons, Fig. 2b. In this scheme, the carboxylate-O2 atom forms two hydrogen bonds. Additional stability to the supramolecular chain is afforded by quinolinyl-C—H⋯O(carboxylate) and methylene-C—H⋯O(hydroxyl) interactions, Table 1via C—Cl⋯π(C4–C9) interactions, Table 1a-axis direction without directional interactions between them, Fig. 2c.The presence of charge-assisted hydroxyl-O—H⋯Oet al., 2016dnorm in Fig. 3a and b (labelled 1–3), corresponding to intermolecular O—H⋯O, N—H⋯O and C—H⋯O interactions, Table 1c and d, indicate the influence of short interatomic H⋯H, F⋯H/H⋯F and F⋯F contacts [Table 2CrystalExplorer3.1 et al., 2007i.e. 11.9%, contribution from H⋯H contacts to the Hirshfeld surface. Conversely, the relative high number of fluorine atoms lying on the surfaces of both the cation and anion, largely participating in F⋯H contacts, gives rise to their providing the greatest contribution, i.e. 40.8%, to the surface.The overall two-dimensional fingerprint plot and those delineated  and 3.0 Å (Cl⋯H), and an arrow-shaped tip at de + di ∼2.8 Å in the fingerprint plots delineated into F⋯H/H⋯F, Cl⋯H/H⋯Cl and F⋯F contacts, respectively. The involvement of chloride and fluoride atoms in C-halogen⋯π contacts, Table 1In the fingerprint plot delineated into H⋯H contacts in Fig. 6et al., 2016et al., 2016et al., 2016et al., 2016i.e. (+)-PhC(CF3)(OMe)CO2−  δ: 1.20–1.35 , 1.55–1.75 , 3.04 , 3.53 , 5.90 , 6.94 , 8.01 , 8.13 , 8.42 , 8.72 , 9.48 ; N—H H not observed. 13C NMR (DMSO-d6) δ: 21.43 (2×), 21.59, 44.51, 58.90, 67.85, 1135.50. 121.17 , 121.21 , 123.64 , 126.37, 127.93 , 128.32, 128.68. 129.9 , 142.78, 146.73 , 150.97, 159.82 . 19F NMR (DMSO-d6) δ: −58.65, −58.84, −66.68. IR (cm−1) 3300–2400 , 1662 (s).A solution of mefloquinium chloride (1 mmol) and sodium difluorochoroacetate (1 mmol) in EtOH (10ml) was refluxed for 20 mins. The reaction mixture was left at room temperature and after two days, colourless crystals of the title salt, (I)Uiso(H) set to 1.2Ueq(C). The O- and N-bound H atoms were refined with the distance restraints O—H = 0.84±0.01 and 0.88±0.01 Å, respectively, and with Uiso(H) = 1.5Ueq(O) and 1.2Ueq(N), respectively.Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S2056989018007703/hb7752sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989018007703/hb7752Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018007703/hb7752Isup3.cmlSupporting information file. DOI: 1844854CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In this compound, C—H⋯O and C—H⋯I hydrogen-bonding interactions, π–π interactions, other short contacts and Pb octahedral chains are present, extending the crystal structure into a three-dimensional supramolecular network.The compound tris bis(dimethyl sulfoxide)di-μ 3-iodido-tetra-μ2-iodido-octaiodidotetralead(II) dimethyl sulfoxide disolvate, (C18H26N2)3[Pb4I14(C2H6OS)2]·2C2H6OS, belongs to a class of organic–inorganic hybrid materials with novel functionalities. In this compound, C—H⋯O and C—H⋯I hydrogen-bonding interactions, π–π interactions, other short contacts and Pb octahedral chains are present, extending the crystal structure into a three-dimensional supramolecular network.The title compound, tris bis(dimethyl sulfoxide)di-μ Viologens show excellent redox and chemical stability. In addition, they can act as effective templates for the construction of various organic–inorganic hybrids, charge-transfer complexes and supramolecular systems  halide-based organic–inorganic hybrids possess a large radius, a flexible coordination environment, and variable stereochemical activities of the lead center ]6− trianion, one and a half BV2+  dications and two DMSO molecules, as shown in Fig. 12+ cation is located on a general position and adopts a non-planar structure, with a dihedral angle of 27.5 (3)° between the planes of the pyridinium rings. In the bipyridinium rings, C—N bond lengths vary from 1.335 (9) to 1.499 (10) Å and C—C bond lengths from 1.336 (17) to 1.636 (17) Å. C—N—C bond angles are in the range 118.6 (6)–121.1 (7)° and C—C—C bond angles in the range 107.9 (9)–122.1 (6)°. The inorganic anion can be considered as a set of mixed face-shared/edge-shared octahedra  lone pairs ]6− and DMSO via C—H⋯I and C—H⋯O hydrogen bonds (Table 14I14)]6− and organic species play an important role in stabilizing the crystal structure  to 4.796 (4) Å (DMF)2(DPB)5] [Pb3I9] [Pb2I6]  iodide complexes have been reported whose structures include chains of face-sharing ideal PbI2  and 10 ml of methanol were stirred under an argon atmosphere until dissolved. 1,1′-Dibutyl-4,4′-bipyridyl cation salt  dissolved in methanol (5 ml) was added to the reaction mixture at room temperature. The resulting precipitate was dissolved in DMSO (3 ml) and placed in a sealed jar of anhydrous ether. Red crystals were produced two weeks later under an argon-protected atmosphere. After filtering and drying under vacuum, red needle-shaped crystals of 0.73 g (72.3%) with high quality were obtained. Analysis calculated for C62H102I14N6O4Pb4S4: C 19.97, H 2.70, N 2.25%. Found: C 19.80, H 2.82, N 2.25%. IR (cm−1): 3291 (w), 3108 (m), 3035 (s), 2931 (w), 2958 (w), 2857 (w), 944 (w), 1636 (m), 1634 (s), 1441 (m), 1060 (s), 833 (s).NaI , PbIUiso(H)= 1.2-1.5Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018016584/ex2016sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018016584/ex2016Isup2.hklStructure factors: contains datablock(s) I. DOI: 1880239CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Bnz⋯OThz (Bnz = benzene and Thz = thiazine) hydrogen bonds form corrugated chains extending along the b-axis direction which are tied into layers parallel to the bc plane by intermolecular C—HMethy⋯SThz (Methy = methylene) hydrogen bonds, enclosing The title compound contains 1,4-benzothiazine and 2,4-dichlorobenzylidene units, where the dihydrothiazine ring adopts a screw-boat conformation. In the crystal, intermolecular C—H 22H15Cl2NOS, contains 1,4-benzothiazine and 2,4-dichlorobenzylidene units, where the dihydrothiazine ring adopts a screw-boat conformation. In the crystal, intermolecular C—HBnz⋯OThz (Bnz = benzene and Thz = thiazine) hydrogen bonds form corrugated chains extending along the b-axis direction which are connected into layers parallel to the bc plane by intermolecular C—HMethy⋯SThz (Methy = methylene) hydrogen bonds, enclosing R44(22) ring motifs. Offset π-stacking interactions between 2,4-dichlorophenyl rings [centroid–centroid = 3.7701 (8) Å] and π-interactions which are associated by C—HBnz⋯π(ring) and C—HDchlphy⋯π(ring)  interactions may be effective in the stabilization of the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.1%), H⋯C/C⋯H (27.5%), H⋯Cl/Cl⋯H (20.6%) and O⋯H/H⋯O (7.0%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HBnz⋯OThz and C—HMethy⋯SThz hydrogen-bond energies are 55.0 and 27.1 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.The title compound, C The molecular and crystal structures, together with the Hirshfeld surface analysis, the intermolecular interaction energies and density functional theory (DFT) computational calculations were carried out at the B3LYP/6-311G and B3LYP/6-311G levels, respectively, for (I)1,4-Benzothiazine derivatives constitute an important class of heterocyclic systems. These molecules exhibit a wide range of biological applications, indicating the fact that the 1,4-benzothiazine moiety is a template potentially useful in medicinal chemistry research and therapeutic applications, such as the anti-inflammatory (Trapani B (atoms S1/N1/C1/C6–C8), adopts a screw-boat conformation with puckering parameters  Å, θ = 68.34 (16)° and φ = 333.95 (17)°. The planar rings A (C1–C6), C (C10–C15) and D (C17–C22) are oriented at dihedral angles of A/C = 60.49 (4)°, A/D = 79.69 (4)° and C/D = 41.29 (4)°. Atoms Cl1 and Cl2 are −0.0156 (3) and 0.0499 (4) Å from ring C and so are almost coplanar.The title compound, (I), contains 1,4-benzothiazine and 2,4-dichlorobenzylidene units Fig. 1, where tBnz⋯OThz (Bnz = benzene and Thz = thiazine) hydrogen bonds form corrugated chains extending along the b-axis direction which are connected into layers parallel to the bc plane by intermolecular C—HMethy⋯SThz (Methy = methylene) hydrogen bonds, enclosing et al., 1995C , may further stabilize the structure, with a centroid–centroid distance of 3.7701 (8) Å, together with π-interactions, i.e. C—HBnz⋯π(ring) and C—HDchlphy⋯π(ring) . The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.1%), H⋯C/C⋯H (27.5%), H⋯Cl/Cl⋯H (20.6%) and O⋯H/H⋯O (7.0%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing.In the crystal, intermolecular C—HCrystalExplorer  and those delineated into H⋯H, H⋯C/C⋯H, H⋯Cl/Cl⋯H, O⋯H/H⋯O, C⋯C, S⋯H/H⋯S and Cl⋯C/C⋯Cl contacts –(h), respectively, together with their relative contributions to the Hirshfeld surface. The most important interaction is H⋯H, contributing 29.1% to the overall crystal packing, which is reflected in Fig. 6b) as widely scattered points of high density due to the large hydrogen content of the molecule with the tip at de = di = 1.17 Å, due to the short interatomic H⋯H contacts (Table 2c), with a 27.5% contribution to the HS, arises from the H⋯C/C⋯H contacts , with a 20.6% contribution to the HS, has a symmetrical distribution of points with the edges at de + di = 2.78 Å arising from the H⋯Cl/Cl⋯H contacts (Table 2e), with a 7.0% contribution to the HS, arises from the O⋯H/H⋯O contacts  have an arrow-shaped distribution of points with the tip at de = di = 1.7 Å. Finally, the characteristic wings resulting in the fingerprint plots delineated into S⋯H/H⋯S and Cl⋯C/C⋯Cl contacts , with 4.0 and 2.2% contributions to the HS, arise from the S⋯H/H⋯S and Cl⋯C/C⋯Cl contacts rm Fig. 3, the whis Table 2. In the s Table 2c, with s Table 2 and are ⋯H Fig. 6d, with s Table 2. The pais Table 2e, with s Table 2 and is vts Fig. 6f have as Figs. 6g and 6hs Table 2 and are dnorm plotted onto the surface are shown for the H⋯H, H⋯C/C⋯H, H⋯Cl/Cl⋯H, O⋯H/H⋯O, C⋯C and S⋯H/H⋯S interactions in Figs. 7a)–(f), respectively.The Hirshfeld surface representations with the function et al., 2015The Hirshfeld surface analysis confirms the importance of H-atom contacts in establishing the packing. The large number of H⋯H, H⋯C/C⋯H, H⋯Cl/Cl⋯H and O⋯H/H⋯O interactions suggest that van der Waals interactions and hydrogen bonding play the biggest roles in the crystal packing   is the sum of the electrostatic (Eele), polarization (Epol), dispersion (Edis) and exchange-repulsion (Erep) energies  were calculated as −20.3 (Eele), −2.6 (Epol), −79.4 (Edis), 60.7 (Erep) and −55.0 (Etot) for C—HBnz⋯OThz hydrogen-bonding interactions, and −5.8 (Eele), −1.0 (Epol), −51.0 (Edis), 39.3 (Erep) and −27.1 (Etot) for C—HMethy⋯SThz hydrogen-bonding interactions.The intermolecular interaction energies are calculated using CE–B3LYP/6-31G energy model available in via density functional theory (DFT) using standard B3LYP functional and 6-311G basis-set calculations , hardness (η), potential (μ), electrophilicity (ω) and softness (σ) are recorded in Table 4E = ELUMO – EHOMO) of the molecule was about 5.3364 eV, and the frontier molecular orbital (FMO) energies, EHOMO and ELUMO, were −8.2479 and −2.9115 eV, respectively.The optimized structure of (I)et al., 2016R1 = Ph and R2 = C; see Scheme 2R1 = Ph and R2 = CH2C≡CH (IIa)        to 36° (for IIf). The other two (IIa and IIc) have the benzothiazine unit nearly planar, with corresponding dihedral angles of ca 3–4°.A search in the Cambridge Structural Database (Groom Z)-2--2H-1,4-benzothiazin-3(4H)-one (3.21 mmol), benzyl chloride (6.52 mmol) and potassium carbonate (6.51 mmol) in dimethylformamide  was added a catalytic amount of tetra-n-butylammonium bromide (0.33 mmol). The mixture was stirred for 24 h. The solid material was removed by filtration and the solvent evaporated under vacuum. The solid product was purified by recrystallization from ethanol to afford colourless crystals in 82% yield.To a solution of  I, global. DOI: 10.1107/S2056989019013586/lh5925Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019013586/lh5925Isup3.cdxSupporting information file. DOI: 1957875, 1957875CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, offset π–π interactions involving inversion-related pyridine rings [centroid-to-centroid distance = 3.4731 (14) Å] link the molecules into columns along the  14H14ClNO3, there is an intramolecular C—H⋯O hydrogen bond forming an S(6) graph-set motif. The molecule is essentially planar with the mean plane of the ethyl acetate group making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-ethoxyquinoline mean plane. In the crystal, offset π–π interactions with a centroid-to-centroid distance of 3.4731 (14) Å link inversion-related molecules into columns along the c-axis direction. Hirshfeld surface analysis indicates that H⋯H contacts make the largest contribution (50.8%) to the Hirshfeld surface.In the title quinoline derivative, C We report herein on its crystal and molecular structures along with the Hirshfeld surface analysis.Quinoline derivatives represent an important class of bioactive heterocyclic compounds in the field of pharmaceuticals (Chu a. The molecule consists of a quinoline fused-ring system (N1/C1–C9) with methoxyethane (O2/C10/C11), ethyl acetate (O3/O4/C13/C14) and a chlorine atom (Cl1) substituents. The intramolecular C5—H5A⋯O3 hydrogen bond (Table 1S(6) graph-set motif, stabilizing the molecular structure and preventing free rotation between the 6-chloroquinoline ring (Cl1/N1/C1–C9) and the ethyl acetate (O3/O4/C12–C14) moiety. Additionally, the presence of this intramolecular C—H⋯O interaction leads to an essentially planar molecular structure , where the ethyl acetate (O3/O4/C12–C14) mean plane is twisted slightly at a dihedral angle of 5.02 (3)° with respect to the mean plane of the ethyl 6-chloro-2-ethoxyquinoline (Cl1/O2/C1–C11) moiety. This essentially planar molecular structure may be considered an important binding mode that can enhance biological activity . They are linked by offset π–π interactions  involving inversion-related pyridine rings. These interactions link the molecules into columns up the c-axis direction with a centroid-to-centroid (Cg⋯Cgi) distance of 3.4731 (14) Å .In the crystal, molecules lie in a plane parallel to the  contact distances from the Hirshfeld surface to the nearest atom inside and outside enables the analysis of the intermolecular interactions through the mapping of dnorm. The Hirshfeld surfaces (HS) mapped over the electrostatic potential (−0.0534 to 0.0319 atomic units) and dnorm (−0.0210 to 1.4779 arbitrary units) are shown in Fig. 3a and 3b. The red spots on the Hirshfeld surface indicate interactions involved in H⋯O contacts. The π–π stacking is confirmed by the small blue regions surrounding bright red spots in the aromatic ring in Fig. 3c, the Hirshfeld surface mapped over the shape-index, and by the flat regions around the aromatic regions in Fig. 3d, the Hirshfeld surface mapped over the curvedness.The Hirshfeld surface analysis  points associated with the hydrogen atoms is shown in Fig. 5b. It is characterized by an end point that points to the origin, indicating the presence of the H⋯H contacts that contribution 50.8%. The Cl⋯H/H⋯Cl contacts between the chlorine atoms inside the Hirshfeld surface and the hydrogen atoms outside the surface and vice versa contribute 16.0% . The O⋯H/H⋯O (10.3%) plot shows two symmetrical wings on the left and right sides . The C⋯C contacts contribute 7.9% , the C⋯H/H⋯C contacts contribute 5.3% , followed by the C⋯O contacts at 3.7%  and the C⋯N contacts at 3.3% .There are no significant classical intermolecular contacts present in the crystal according to the analysis of the crystal structure using 0% Fig. 5c. The Oes Fig. 5d. The C9% Fig. 5e, the C3% Fig. 5e, follo7% Fig. 5g and th3% Fig. 3h.Gaussian 09 package  was also calculated using DFT methods at the B3LYP/6-311+G level of theory using the et al., 2016et al., 2010aet al., 2010bet al., 2010cet al., 2010det al., 2009et al., 2009A search of the Cambridge Structural Database  of tetra-n-butylammonium bromide (TBAB). The reaction mixture was stirred at room temperature in DMF for 24 h. After removal of salts by filtration, the DMF was evaporated under reduced pressure and the residue obtained was dissolved in dichloromethane·The organic phase was dried over Na2SO4 then concentrated in vacuo. The resulting mixture was chromatographed on a silica gel column [eluent: ethyl acetate/hexane (1:9 v/v)]. Colourless crystals were obtained when the solvent was allowed to evaporate (yield: 32%).A solution of 0.5 g (1.99 mmol) of ethyl 6-chloro-2-oxo-1,2-dihydroquinoline-4-carboxylate in 25 ml of DMF was mixed with 0.3 ml (3.98 mmol) of bromoethane, 0.55 g (3.98 mmol) of KUiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms. A rotating group model was applied to the methyl groups.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989019007473/mw2143sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019007473/mw2143Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019007473/mw2143Isup3.cmlSupporting information file. DOI: 1890687CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


E) -methoxybenzaldehyde oxime derivatives, namely ⋯O(hydroxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O—H(oxime)⋯O(hydroxy) hydrogen bonds generate symmetric 4 from the O—H(oxime)⋯O(hydroxy) and C—H(2-methoxy)⋯O(hydroxy) hydrogen bonds.The crystal structures of four ( E)-methoxybenzaldehyde oxime derivatives, namely ⋯O(hydroxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O—H(oxime)⋯O(hydroxy) hydrogen bonds generate symmetric R22(6) dimers. A more complex dimer is generated in 4 from the O—H(oxime)⋯O(hydroxy) and C—H(2-methoxy)⋯O(hydroxy) hydrogen bonds. In all cases, further interactions, C—H⋯O and C—H⋯π or π–π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.The crystal structures of four ( The last survey of the classical hydrogen-bonding patterns in benzaldehyde oximes reported in 2010 . In compounds 1–3, the 2-methoxy group and the hydrogen of the oxime moiety have an s-cis arrangement. In contrast, in both molecules of compound 4, the 2-methoxy group and the hydrogen atom of the oxime moiety have an s-trans arrangement. The s-trans arrangement of the 2-alkoxy group and hydrogen atom of the oxime units in compound 4 is very much rarer than the s-cis arrangement found in compounds 1–3 and other non-salicylaldoximes. A search of the Cambridge Structural Database -2-({2-[(E)-(hydroxyimino)methyl]phenoxy}methyl)-3-p-tolylacrylonitrile methyl]phenoxy}methyl)-3-(2-methylphenyl)acrylonitrile -2-({2-[(E)-(hydroxyimino)methyl]phenoxy}methyl)-3-phenylacrylonitrile  chains, illustrated in Fig. 61 are two weaker hydrogen bonds, namely, C3—H3⋯O13ii and C21—H21C⋯O13iii, as well as a weak π–π stacking interaction . These three interactions generate the molecular arrangement shown in Fig. 7ii hydrogen bonds generate C7 chains in the c-axis direction, while the C21—H21C⋯O13iii hydrogen bonds form C(8) spiral chains along the a-axis direction: together these hydrogen bonds form c-axis direction. The involvement of the weaker C3—H3⋯O13ii, C21—H21C⋯O13iii and π–π interactions, along with the stronger O13—H13 ⋯N12i hydrogen bonds, creates the three-dimensional structure for 1.In the crystal of s Table 2, forming1, molecules of 2 are primarily linked by strong O13—H13 ⋯N12i hydrogen bonds (Table 3C(3) chains: as such chains are very similar to those in compound 1, see Fig. 6C(3) chain in compound 2. Other intermolecular interactions in 2 are the weaker C21—H21B⋯O31iii and C31—H31B⋯O13iv hydrogen bonds and a C31—H31C⋯Cg1v interaction involving the C1–C6 ring. These three interactions combine to form the arrangement illustrated in Fig. 8B⋯O31iii hydrogen bonds on their own generate C(6) chains, which propagate in the a-axis direction while the C31—H31B⋯O13iv hydrogen bonds generate spiral C(9) chains in the b-axis direction. Together these hydrogen bonds generate a network of C⋯Cg1v interactions lead to chains along the a-axis direction. The involvement of the weaker C21—H21B⋯O31iii, C31—H31B⋯O13iv C and C—H⋯π interactions, along with the stronger O13—H13 ⋯N12i hydrogen bonds, creates a three-dimensional structure for 2. C4—H4⋯O12ii hydrogen bonds also occur.As in s Table 3, forming3, i hydrogen bonds (Table 4A(methoxy)⋯O13ii hydrogen bonds provide a two-molecule-wide ribbon. Within the ribbons are 3 is the C41—H41C⋯Cg1iii interaction, which generates a tilted ladder assembly, propagating in the a-axis direction, with the C⋯Cg1iii interactions as the supports.In compound s Table 4, as illu4, each of the two independent molecules forms symmetric dimers, see Fig. 10i and O113—H113⋯O121i hydrogen bonds  chains, while in compounds 3 and 4, they are responsible for the creation of the dimers. In compound 3, the fins ending at de, di = 1.9,1.1 Å are due to C(π)⋯H/C(π)⋯H contacts. The FP plots for Mol A and Mol B of compound 4 are asymmetric because of the different interactions of each molecule. The double wings in the FP plot for Mol A in the second quadrant are complementary to those displayed in the fourth quadrant by MolB and relate to C⋯H close contacts connecting the two molecules. The spike ending at di, de = 1.1 Å in Mol A is due to H⋯H contacts.Hirshfeld surfaces -chain-forming compounds 1 and 2 show higher percentages of H⋯H and C⋯C contacts, but a lower percentage of H⋯C/C⋯H contacts, than the dimer-forming compounds 3 and 4.The percentages of the various atom–atom contacts, derived from the fingerprint plots, for the four compounds are shown in Table 6et al., 20162 and 3. The classical hydrogen bonds in 3,5-dimethoxybenzene oxime generate C(3) chains  in the CSD database with oxime 1, 371–373 K for 2, 378–380 K for 3 and 370–371 K for 4.The title compounds were prepared from hydroxyamine and the corresponding benzaldehyde in methanol in the presence of potassium carbonate and were recrystallized from methanol solutions, m.p. = 364–365 K for compound Uiso(H) = 1.2–1.5Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 710.1107/S2056989018014020/qm2129sup1.cifCrystal structure: contains datablock(s) 1, 2, 3, 4, global. DOI: 10.1107/S2056989018014020/qm21291sup2.hklStructure factors: contains datablock(s) 1. DOI: 10.1107/S2056989018014020/qm21292sup3.hklStructure factors: contains datablock(s) 2. DOI: 10.1107/S2056989018014020/qm21293sup4.hklStructure factors: contains datablock(s) 3. DOI: 10.1107/S2056989018014020/qm21294sup5.hklStructure factors: contains datablock(s) 4. DOI: Click here for additional data file.10.1107/S2056989018014020/qm21291sup6.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989018014020/qm21292sup7.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989018014020/qm21293sup8.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989018014020/qm21294sup9.cmlSupporting information file. DOI: 1871165, 1871164, 1871163, 1871162CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The supramolecular structure is mainly governed by C—H⋯N hydrogen-bonded centrosymmetric dimers, C—H⋯O and C—H⋯S hydrogen bonds and S⋯π stacking interactions, which together lead to the formation of a layered crystal packing.The molecular conformation is stabilized  15H13N3O2S, crystallizes in the monoclinic space group P21/n and its molecular conformation is stabilized via intramolecular C—H⋯O and C—H⋯N contacts. The supramolecular structure is mainly governed by C—H⋯N hydrogen-bonded centrosymmetric dimers, C—H⋯O and C—H⋯S hydrogen bonds and S⋯π and π–π stacking interactions which, together, lead to the formation of a layered crystal packing. The intermolecular interactions were further evaluated through the molecular electrostatic potential map and Hirshfeld fingerprint analysis.The title compound, C N-heterocycles (having two carbon and three nitrogen atoms) because of their unique structural and chemical properties methanone (1).In general, the 1,2,3-triazole nucleus is the most fundamental heterocyclic component found in various pharmacologically active agents  in the asymmetric unit  Å] and C11—H11⋯N1 [C11⋯N1 = 2.950 (2) Å] contacts  of the methoxy group with the triazol nitrogen N3 [C15⋯N3 = 3.490 (3) Å] and the thiophene hydrogen H12 (sp2) with the triazol nitrogen N1 [C12⋯N1 = 3.768 (2) Å]. These are extended in an alternate fashion, forming ribbons along the [101] direction  [3.492 (2) Å] interactions along the [010] direction, forming a corrugated sheet perpendicular to the (101) plane , and two-dimensional fingerprint plots (thiophen-2-yl)methanone subunit resulted in one hit  =1.5Ueq(C) for the methyl group and C—H = 0.95Å with Uiso(H) = 1.2Ueq(C) for the aromatic C atoms.Crystal data, data collection and structure refinement details are given in Table 210.1107/S2056989018010654/xi2009sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018010654/xi2009Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018010654/xi2009Isup3.cmlSupporting information file. DOI: 1850683CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


While there are two C—H⋯O weak intermolecular interactions present in both (I) and (II), the change of substituent from chlorine to methyl has given rise to an additional weak C—H⋯O intermolecular interaction that is relatively stronger than the other two. However, the presence of the stronger C—H⋯O interaction in (II) has not disrupted the validity of the chloro-methyl exchange rule. Details of the crystal structures and Hirshfeld analyses of the two compounds are presented.Instances of crystal structures that remain isomorphous in spite of some minor changes in their respective molecules, such as change in a substituent atom/group, can provide insights into the factors that govern crystal packing. In this context, an accurate description of the crystal structures of an isomorphous pair that differ from each other only by a chlorine–methyl substituent,  The prediction of crystal structures has emerged as an exciting field involving researchers from diverse fields primarily because of its challenging complexity, which is considered analogous to that of the protein-folding problem. Attempts made in the field of crystal-structure prediction, its present status and the challenges ahead were discussed in detail in a recent article et al., 2011et al., 2018et al., 2019et al., 2007et al., 2008From a pharmacological view point, the title compounds (I)The molecular structures of (I)Q(2) = 0.4011 (2) Å and φ = 180.3733 (3)° for (I)Q(2) = 0.4047 (2) Å and φ = 180.3444 (3)° for (II)Q = 0.5572 (16) Å, θ = 138.9 (2)°, φ = 219.8 (3)° in (I)Q = 0.5603 (17) Å, θ = 137.7 (2)°, φ = 219.6 (3)° in (II)As expected, the conformational features of both compounds are nearly identical, as shown in a overlay diagram Fig. 3. The fivThe dihedral angle between the mean planes of the two chlorophenyl groups in (I)viz. C10—H10⋯O2 and C16—H16⋯O2, which are identical in nature and characteristic of similar fundamental molecular interaction patterns are present (Tables 3b-axis direction in both (I)b-axis direction  Tables 3 and 4 ▸.viz. C36—H36A⋯O1, that is stronger than the two characteristic weak intermolecular interactions and involves the replaced substituent methyl group (C36—H36A) as a donor and the piperidinone O1 atom as an acceptor (see Table 4In (II)B⋯π interaction observed in (I)Cg3⋯Cg3 distances of 3.7459 (2) Å in (I)Cg3 is the centroid of the C14–C19 ring. The shortest Cl⋯Cl distance observed [Cl1 ⋯Cl1] is 4.088 (1) Å and bears no structural significance.In addition, a weak C—H⋯π interaction involving different donor groups and acceptor π-ring systems is present in both (I)et al., 2016R factors less than 0.05) gave only three hits: 5′′-(4-chlorobenzylidene)-4′-(4-chlorophenyl)-1′,1′′-dimethyl-2H,4′′H-dispiro-2,4′′-dione -pyridinone  analysis was used to investigate and visualize the weak intermolecular interactions influential in the packing of the molecules in the crystal. The visual representation of molecular interactions on this isosurface is determined using two parameters, CrystalExplorer3.0 E)-2-chlorophenylmethylidene] tetrahydro-4(1H)- pyridinone (1 mmol), acenaphthenequinone (1 mmol) and sarcosine (1 mmol) was dissolved in methanol (15 mL) and refluxed for 30 min. After completion of the reaction, as evident from TLC, the mixture was poured into water (50 mL) and the precipitated solid was filtered and washed with water (100 mL) to obtain pure (I)fR  0.40. Suitable crystals for single-crystal X-ray studies were obtained by recrystallization of the product from ethanol.For (I)E)-2-methylphenylmethylidene] tetrahydro-4(1H)-pyridinone (1 mmol), acenaphthenequinone (1 mmol) and sarcosine (1 mmol) in methanol (15 mL) to yield yellow crystals.A similar procedure for (II)Uiso(H) = 1.5Ueq(C) for methyl H atoms or 1.2Ueq(C) otherwise. The H atoms of the methyl atoms C35 and C36 in (II)Crystal data, data collection and structure refinement details are summarized in Table 510.1107/S2056989019012428/jj2215sup1.cifCrystal structure: contains datablock(s) I, II. DOI: 10.1107/S2056989019012428/jj2215Isup2.hklStructure factors: contains datablock(s) I. DOI: 10.1107/S2056989019012428/jj2215IIsup3.hklStructure factors: contains datablock(s) II. DOI: 1951894, 1569029CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


II ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. Two C—H⋯O and two C—H⋯S intramolecular interactions occur. In the crystal, molecules are linked by C—H⋯O and C—H⋯S hydrogen bonds, forming a three-dimensional supramolecular architecture.In the title compound, the Zn S)zinc(II) acetone hemisolvate, [Zn(C4H7O2S2)2(C6H16N2)]·0.5C3H6O, the ZnII ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. The amine ligand is disordered over two orientations and was modelled with refined occupancies of 0.538 (6) and 0.462 (6). The molecular structure features two C—H⋯O and two C—H⋯S intramolecular interactions. In the crystal, molecules are linked by weak C—H⋯O and C—H⋯S hydrogen bonds, forming a three-dimensional supramolecular architecture. The molecular structure was optimized using density functional theory (DFT) at the B3LYP/6–311 G level. The smallest HOMO–LUMO energy gap (3.19 eV) indicates the suitability of this crystal for optoelectronic applications. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules. Half a molecule of disordered acetone was removed with the solvent-mask procedure in OLEX2  and this contribition is included in the formula.In the title compound, bis(2-methoxyethyl xanthato-κ al. 2009. J. Appl Xanthate is a bidentate monoanionic sulfur–sulfur donor ligand. It stabilizes complexes of most of the transition elements and can bind metal centers in monodentate, isobidenate, anisobidenate or ionic modes. Xanthates have the ability to inhibit the replication of both RNA and DNA viruses II ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine molecule and two S atoms from two 2-methoxyethylxanthate molecules. The Zn1—N1, Zn1—N2, Zn1—S1 and Zn1—S3 bond lengths are 2.141 (5), 2.123 (5), 2.3107 (9) and 2.3050 (9) Å, respectively  Å, which is typical of a single bond whereas the carbon-to-sulfur S2 distance of 1.647 (3) Å is typical of a carbon-to-sulfur double bond. In the molecule, weak C1—H1C⋯O8, C2A—H2AB⋯O11, C5A—H5AA⋯S1 and C6—H6C⋯S4 intramolecular interactions are observed 2(bipy)] [CSD 2(C6H16N2)]  and [Ni(moexa)2phen] (benzene solvate), moexa = O-methoxyethylxanthato-S,S′ 2]  and the lowest unoccupied molecular orbitals (LUMOs) are named as frontier molecular orbitals (FMOs). The FMOs play an important role in the optical and electric properties. The frontier orbital gap characterizes the chemical reactivity and the kinetic stability of the molecule. A molecule with a small frontier orbital gap is generally associated with a high chemical reactivity, low kinetic stability and is also termed a soft molecule. The density functional theory (DFT) quantum-chemical calculations for the title compound were performed at the B3LYP/6–311 G level  level of theory and is illustrated in Fig. 43CO2)·2H2O  in 2-methoxyethanol. A hot solution of potassium 2-methoxyethylxanthate  in 2-methoxyethanol was added and the mixture was stirred for 30 min. Water was added to the mixture and a white precipitate was formed. The product was recrystallized from acetone.Tetramethylethylenediamine  was added to a hot solution of Zn(CHUiso(H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) otherwise. All atoms of the amine ligand are disordered and were modelled as two orientations with relative occupancies of 0.538 (6) and 0.462 (6). The diffuse electron density of half an acetone solvent molecule was removed with the solvent-mask procedure implemented in OLEX2  I. DOI: 10.1107/S2056989019013148/lh5921Isup2.hklStructure factors: contains datablock(s) I. DOI: 1420207CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The difference was ascribed to the HOMO of the amide group, which expands in the vertical direction (πO) rather than in the plane (nO). S···X interactions in four model proteins, phospholipase A2 (PLA2), ribonuclease A (RNase A), insulin, and lysozyme, have also been analyzed. The results suggested that S···X interactions would be important factors that control not only the three-dimensional structure of proteins but also their functions to some extent. Thus, S···X interactions will be useful tools for protein engineering and the ligand design.In organic molecules a divalent sulfur atom sometimes adopts weak coordination to a proximate heteroatom (X). Such hypervalent nonbonded S···X interactions can control the molecular structure and chemical reactivity of organic molecules, as well as their assembly and packing in the solid state. In the last decade, similar hypervalent interactions have been demonstrated by statistical database analysis to be present in protein structures. In this review, weak interactions between a divalent sulfur atom and an oxygen or nitrogen atom in proteins are highlighted with several examples. S···O interactions in proteins showed obviously different structural features from those in organic molecules ( Nagao ,33 reporives (3) , bis[2-(fide (4) , β-hydro (4) [5) , and thi [5) [6) .Weak nonbonded interactions are important physicochemical forces that control the structure of proteins . Ionic iet al. [The SSC and CSC groups involved in cystine and methionine residues, however, were usually considered just as hydrophobic moieties in folded protein structures until recently, except for S···C(π) interactions  and weaket al.  suggesteet al. ,28,51,52et al. ,47. Meanet al. , but the et al. [ etc.) atomic contacts involved in 604 high-resolution (≤2.0 Å) heterogeneous X-ray structures selected from the Protein Data Bank [d = rS···X − vdwS − vdwX), the directionality around the S and X atoms, and the location along the amino acid sequence revealed distinct structural features of the S···X interactions. In case of the most frequent S···O interactions, both SSC and CSC S atoms tend to approach a main-chain O atom perpendicularly to the amide plane (the πO direction), and the O atom tends to approach the S atom from the backside of the S–S or S–C covalent bonds (the σS* direction). Similar directionalities of the S(CSC)···O interactions were also reported by Pal and Chakrabarti [O orbital, not πO, is usually used to form the interaction.Nonbonded S···X interactions in proteins have recently been pursued by several research groups ,23,18,21 et al.  thoroughata Bank . Statistkrabarti . The strd ≤ 0.0 Ǻ), a probability of S···O contacts increases significantly, suggesting the presence of specific S···O interactions in proteins. According to the statistical analysis for the obtained data, four types of nonbonded S···X interactions have been clearly characterized, i.e., S–S···O=C, C–S···O=C, C–S···N, and S–S···S–S interactions [ractions .O → σS* orbital interaction is obvious. The S–S···O=C interactions are most frequently observed in helices, suggesting that the S···O interactions would support the stability. The C–S···O=C interaction formed between a methionine side-chain and a main-chain peptide group has a similar character to the S–S···O=C interaction, but the strength of the interaction is weaker with attenuated directionality. Similarly, the C–S···N interaction between a methionine side-chain and a main-chain peptide group can also be characterized by the linear C–S···N atomic alignment and the vertical access of the S atom to the amide plane, suggesting a contribution from the πN → σS* orbital interaction. On the other hand, most of close S···S contacts in proteins can be assigned to S–S···S–S interaction, which would be stabilized by the nS → σS* orbital interaction in a similar manner to that observed in organic crystals [A majority of close S···O contacts for an SSC group in proteins is assigned to S–S···O=C interactions, which can be characterized by the linear S–S···O atomic alignment and the vertical access of the S atom to the carbonyl plane as shown in crystals .Ab initio calculation was carried out for the model complexes (CH3SSCH3 + CH3CONHCH3 and CH3SCH3 + CH3CONHCH3) to investigate the nature of the S···X interactions observed in proteins [O → σS* orbital interaction  lying in the carbonyl plane rather than the π orbital expanding perpendicular to the plane. The reason for the observed discrepancy in the directionality between the S···O interactions in proteins and organic molecules can be explained on the basis of the HOMO levels of various carbonyl compounds . As grapO level of amide CH3CONHCH3 is remarkably raised compared with other carbonyl compounds, while the nO level remains almost unchanged. The elevation of the πO orbital would be due to the conjugation between the N lone pair and the carbonyl group. Thus, inversion of the energy levels of nO and πO would be responsible for the observed directional preferences of the S···O interactions in proteins.However, the π et al. [N-acetylglucosamine-thiazoline and β-hexosaminidase and between benzophenone and porcine odorant-binding protein [− ligand and the imidazole ring of His109 in lactoperoxidase [The importance of S···O interactions in the enzymatic function of proteins has been pointed out for some particular cases. Taylor and Markham  suggeste et al.  reported protein . Importa protein . More reroxidase  and betwroxidase  were sugAccording to the comparison between the results from database analyses and ab initio calculation, it was clear that the directional preferences of the S···O interactions observed in protein structures are in accord with the profiles of the potential surfaces calculated for the isolated model complexes . An examProtein structures are generally considered to be flexible because they are governed only by weak nonbonded interactions. Therefore, coincidence of the statistical conformational preference for the interaction of proteins with the potential surface calculated for the isolated model is to be noticed and would have important implications in protein architecture. The detailed analysis revealed the following features . The linThe directionality, however, is easily affected by crystal packing force for organic molecules. Thus, the order of the factors that control molecular structure of organic molecules and proteins in the solid state can be summarized as shown in S* direction), irrespective of the types of carbonyl groups. On the other hand, the S atom tends to approach the O atom either within the carbonyl plane (in the nO direction) or from the vertical direction (in the πO direction). In the case of S···O(amide) interactions, the vertical direction is significantly preferred, due probably to elevation of the πO orbital. The linearity of the S···O interactions in organic molecules would overcome the crystal packing force, whereas the vertical nature of the S···O(amide) interactions may be affected by the packing force. The verticality, however, would survive in protein structures. These structural features will be informative for protein engineering and molecular design of functional organic sulfur compounds.The O atom has strong tendency to approach the S atom from the backside of the S–C or S–S bond (in the σ2 (PLA2) was the first example of such proteins [2 family. The results are summarized in this section.With a success in characterization of S···X interactions in proteins, we subsequently sought out particular protein families or domains, for which specific S···X interactions are commonly present in a wide range of the structures registered in the Protein Data Bank . Phosphoproteins . We have2 [2 family; PLA2 and snake PLA2 (sPLA2). Comprehensive search for close S···X  contacts in the structures of the PLA2 domain, which were retrieved from protein data bank, revealed the presence of four common S···O interactions, i.e., S(C44)···O(D40), S(C61)···O(A55), S(C84)···O(C96), and S(C98)···O(F94), and one common S···N interaction, i.e., S(M8)···N(R100), as shown in 2 is decreased in the M8,20L mutant [PLA2 ,63, a smL mutant . This wo2 domain. For this domain group, the phylogenetic dendrogram was already analyzed by Ohno et al. [2 involved in venom of snakes inhabiting the southern islands of Japan. Mapping the common S···O and S···N interactions observed by the database analysis, we found that most of the S···X interactions make clusters on the dendrogram. The results suggested a possible role of S···X interactions in molecular evolution of proteins.On the other hand, an evolutional aspect of the S···X interactions was analyzed for the sPLAo et al.  using th i.e., S(C26)···Oγ(T99) and S(C65)···O(Q69), and one common S···N interaction, i.e., S(C58)···N(P117), were characterized. The locations along the amino acid sequence are shown in RNase A  is a typC65)···OQ, and oneIn some RNase A structures complexed with a substrate, close S···X contacts between the S atom of the C65 residue and the substrate were found. Examples are S(C65)···O(ADT) in 8RSA , S(C65)·i.e., S(C20)···O(E17) and S(C19)···O(L15), were found within A and B chains, respectively, among the 23 high-resolution (≤2.0 Å) structures. Insulin  is a pepi.e., S(C127)···O(I124), and three common S···N interactions, i.e., S(C30)···Nε(W123), S(C80)···N(N65), and S(C127)···Nη(R5), were characterized as shown in Lysozyme  consists2 and sPLA2 were described in reference [Details of the database analysis of the S···X interactions in PLAeference . SimilarThe three-dimensional structure, hence the function, of a protein is controlled by the interplay of a number of weak nonbonded interactions, such as hydrogen bond, van der Waals forces, and hydrophobic interaction. According to the results from the database analyses and theoretical calculation summarized in this review, it would be concluded that hypervalent S···X interactions are also a member of such weak interactions. ab initio calculation. For four particular proteins, i.e., PLA2, RNase A, insulin, and lysozyme, unique S···X interactions have been characterized, and some were suggested to play roles in the stability of the native structures and the functions to some extent.Sulfur-containing functional groups of cystine (an SSC group) and methionine (a CSC group) were previously considered to be just hydrophobic moieties in protein structures, but they are indeed able to form specific nonbonded interactions with nearby polar non-hydrogen atoms  in folded proteins. A unique directionality of the S···X interactions see  would bei.e., integration of the database analyses and theoretical calculation, will be useful for characterization of other weak nonbonded interactions hidden in molecules as well as protein structures. Finally, the statistical analyses using the both protein and organic molecule structure databases demonstrated that the order of the strength of the factors that control molecular structures in the solid state can be expressed as shown in


The resulting compounds, bis disulfide, C8H6O2S4S2, and bis diselenide, C8H6O2Se6, are isotypic.By  8H6O2S6 and C8H6O2S4Se2, are isotypic with very similar cell parameters. The complete molecules constitute the asymmetric units, despite being chemically perfectly symmetric. The most prominant differences in the metrical parameters arise from the distinct sizes of sulfur and selenium in the dichalcogenide bridges, with C—S—S—C and C—Se—Se—C torsion angles of 70.70 (5) and 68.88 (3)°, respectively. The crystal packing is determined by weak non-classical hydrogen-bonding interactions. One carbonyl oxygen but not the other participates in C—H⋯O interactions zigzagging along the b axis, forming infinite chains. This is complemented by an intramolecular C—H⋯S interaction and further intermolecular C—H⋯S (C—H⋯Se) interactions, resulting in a three-dimensional network. The interactions involving the bridging chalcogenides form chains protruding along the c axis.The two title compounds, C In related disulfides they range from 52.08 to 109.82°  are essentially planar, with maximum deviations from the least-squares plane of 0.028 and 0.022 Å for the disulfide and for the diselenide, respectively, corresponding to the distances from atom S1 to the O1—S1—S2—C1—C2—C3 plane in both cases. The dihedral angles between the O1—S1—S2—C1—C2—C3 and the O2—S5—S6—C6—C7—C8 planes are 33.8 (2)° for the disulfide and 28.89 (11)° for the diselenide. Here, a smaller torsion angle around the dichalcogenide bridge is accompanied by a smaller angle between the two planes of the 1,3-ene-dithiol-2-one moieties.B⋯O1i interactions zigzagging along the b axis, forming infinite chains  Å for the disufide and 3.369 (5) Å for the diselenide. This is complemented by two intramolecular interactions between the two chalcogens of the dichalcogenide bridges and the adjacent methyl substituents (C4—H4A⋯S3/Se1 and C5—H5A⋯S4/Se2) with D⋯A distances of 3.244 (2) for S3, of 3.234 (2) for S4, of 3.354 (4) for Se1, and of 3.341 (4) for Se2. Further intermolecular C—H⋯S and C—H⋯Se interactions contribute to the formation of a three-dimensional network. The interactions involving the bridging chalcogenides form chains protruding along the c axis . The first such thione crystal structure was reported in 1999 by Cerrada et al., which comprises an S—S-linked [C3S5—C3S5]2− dianion 2Cp complexes by coordination of thiolate sulfur to iron  by Kumar et al. selenolothiophen-6-yl}diselenide was formed unexpectedly by the reaction of 2-[(triphenylphosphonio)methyl] thiophene chloride with sodium hydrogen selenite , and LDA  was added dropwise over 5 min. The mixture was allowed to stand for 35 min, warmed to ice-bath temperature and after a further 10 minutes quenched with a saturated aqueous solution of NH4Cl (around 20 ml). The organic phase was diluted with EtOAc, separated and the aqueous phase re-extracted with Et2O (2 × 15 ml). The combined organic phases were washed with brine, dried and the solvent evaporated in vacuo to give a yellowish oil as crude product. This was purified by chromatography (silica gel), eluting with EtOAc/petroleum ether (40/60) 3:97 v/v to give 4-methyl-5-tri-n-butylstannyl-1,3-dithiol-2-one as the major product. During purification, a yellowish oily fraction was isolated and subsequently stored at 253 K, forming large yellow crystals. Crystallographic evaluation of these crystals reveals the formation of the side product bis disulfide.Preparation of bis diselenide: The synthesis was carried out under an inert gas atmosphere of nitrogen, whereas the purification steps were carried out in air. To a solution of 4-methyl-5-tri-n-butylstannyl-1,3-dithiol-2-one  in freshly distilled dioxane (5 ml) was added freshly sublimed selenium dioxide . The reaction mixture was heated at reflux temperature for 6 h. After cooling, the solution was filtered through celite. Solvent removal gave an orange solid . Yellow crystals suitable for crystallographic analysis were obtained by recrystallization from acetone.iUso(H) = 1.5Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018007454/wm5446sup1.cifCrystal structure: contains datablock(s) CSV72a12, it14ii. DOI: 10.1107/S2056989018007454/wm5446CSV72a12sup2.hklStructure factors: contains datablock(s) CSV72a12. DOI: 10.1107/S2056989018007454/wm5446it14iisup3.hklStructure factors: contains datablock(s) it14ii. DOI: 1843766, 1843765CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the 1:1 cocrystal of nicotinamide and 2-chloro-5-nitrobenzoic acid, the molecules form hydrogen bonds through O—H⋯N, N—H⋯O, and C—H⋯O interactions along with N—H⋯O dimer hydrogen bonds of nicotinamide. Further additional weak π–π interactions stabilize the molecular assembly of this cocrystal. 7H4ClNO4·C6H6N2O, nicotinamide (NIC) and 2-chloro-5-nitrobenzoic acid (CNBA) cocrystallize with one molecule each of NIC and CNBA in the asymmetric unit. In this structure, CNBA and NIC form hydrogen bonds through O—H⋯N, N—H⋯O and C—H⋯O interactions along with N—H⋯O dimer hydrogen bonds of NIC. Further additional weak π–π interactions stabilize the molecular assembly of this cocrystal.In the title 1:1 cocrystal, C In the asymmetric unit, an (CNBA)O–H⋯N interaction plays a prime role in the molecular recognition of this cocrystal  crystallizes in the monoclinic space group al Fig. 1.et al., 1990via C—H⋯O hydrogen bonding and form a tetrameric ring with two molecules each of NIC and CNBA with et al., 1990bc plane O—H⋯N(NIC) hydrogen bond and additional (NIC)N—H⋯O(CNBA) and (NIC)C—H⋯O(CNBA) hydrogen bonds are observed Fig. 2. In thisne Fig. 3.CrystalExplorer  and nicotinamide  in a minimum amount of ethanol and made up to a volume of 10 ml. Ten different combinations of the mixture were prepared using ethanol–hexane as the solvent mixture over the ratio range 1:1 to 1:10. The mixture was kept in a 5 ml beaker and covered with parafilm, with four to five small holes in it. These solutions were allowed to evaporate slowly at room temperature (27 °C) over several days to obtain single crystals. After a few days, colourless crystals were obtained from ethanol–hexane solutions with concentration ratios of 1:10, 1:2 and 1:4. The melting point of the obtained crystal was 159.7 °C.Crystal data, data collection, and structure refinement details are summarized in Table 210.1107/S2056989019013859/eb2025sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989019013859/eb2025Isup2.hklStructure factors: contains datablock(s) I. DOI: 1958621, 1958621CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N]. A carboxylic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water molecules and VO2F2− ions of adjacent molecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.The crystal structure of the title molecular complex, [Ag It has recently been shown 2(tr)2}2+ binuclear fragment, two N atoms remain uncoordinated and have potential for further interactions. In aqueous reaction media, vanadium oxofluorides exist in anionic forms with weakly coordinated water molecules that are very labile toward N-donor ligand substitution. Thus, a combination of an AgI–triazole cation and VOF anions lead to the neutral tetranuclear {AgI2(VVO2F2)2(tr)4} unit, which was found in the structure of the title [Ag2(VO2F2)2(tr-ad-COOH)4]·4H2O complex I  bond lengths , while the other two 1,2,4-triazole groups combine the Ag and V centres [Ag⋯V= 3.5376 (6) Å]. The VV atom possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N] with short V—O bonds , V—F bonds  and an elongated V—N bond [2.152 (3) Å]. The polyhedra can be more precisely described by the Reedijk’s factor τ 2(tr)4} is formed. A search in the Cambridge Structural Database 2[Mo4O13]}·2H2O  Å , while another COOH group, as a hydrogen-bond acceptor, is directed toward the F atom of a {VO2F2} anion . Two water molecules are interbonded [O2W—H3W⋯O1W = 2.753 (4) Å] and additionally act as hydrogen-bond donors with O and F atoms from the neighboring {VO2F2} anions and as hydrogen-bond acceptor (in the case of O2W ) with the O3 atom from an adjacent carboxylic group. Some weak contacts between the triazole C—H groups and F atoms of the VOF anions are also observed.The structure of k Figs. 2 and 3 ▸.tr-ad-COOH) was synthesized in 63% yield by refluxing 3-amino-adamantane-1-carboxylic acid , tr-ad-COOH , V2O5  and 5 mL of water with aqueous HF  was added into a Teflon vessel. Then the components were heated at 423 K for 24 h and slowly cooled to room temperature over 50 h, yielding light-yellow prisms of I .1--3-carboxyadamantane (2), C—H = 0.98 Å (adamantane CH) and with Uiso(H) = 1.2Ueq(C). O-bound hydrogen atoms were located in a difference-Fourier map and then refined with O—H = 0.82 Å (carboxylic) or 0.85 Å (H2O) with Uiso(H) = 1.5Ueq(O).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989019006844/zq2246sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019006844/zq2246Isup2.hklStructure factors: contains datablock(s) I. DOI: 1915603CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information: