Similarly, molecule (2) presents the same bridging group, but it connects two nearly planar appendants, each comprising a phenyl ring bonded with a hydroxyl and two aldehyde groups. Compound (2) exhibits a strong visible luminescence when excited with ultraviolet radiation.The molecule of , and 5,5′-bis, C19H16O6, (2), crystallize with one molecule in the asymmetric unit. In molecule (1), a >C(CH3)2 group bridges two nearly planar salicylaldehyde groups [r.m.s deviations = 0.010 (1) and 0.025 (2) Å], each comprising a planar phenyl ring bonded with a hydroxyl and an aldehyde group. Similarly, compound (2) has the same bridging group, but it connects two nearly planar appendants [r.m.s deviations = 0.034 (1) and 0.035 (1) Å], each comprising a phenyl ring bonded with a hydroxyl and two aldehyde groups. Molecule (1) exhibits a bridge angle of 109.5 (2)° with the salicylaldehyde planes subtending a dihedral angle of 88.4 (1)°. In contrast, molecule (2) presents a bridge angle of 108.9 (2)° with its appendants subtending a dihedral angle of 79.6 (3)°. Both molecules exhibit two intramolecular O—H⋯O hydrogen bonds involving the phenolic H atoms and carboxyl O-atom acceptors. In the crystal of (2), O—H⋯O hydrogen bonds between one of the hydroxyl H atoms and a carboxyl O atom from a symmetry-related molecule form a chain along [102) exhibits a strong visible luminescence when excited with ultraviolet radiation.The title compounds 5,5′-bis, C These precursor compounds present a >C(CH3)2 group that bridges two salicylaldehyde moieties (1) or two phenyl groups with an hydroxyl and two aldehyde appendants (2). The various functional groups in these molecules determine their chemical and physical properties, and the ability to modify them provides the title compounds with a wide versatility and the multifunctionality required for synthesizing safer and better performance materials for future civilian and military applications. For instance, the title compounds may be used for the non-toxic, isocyanate-free synthesis of polyurethanes  is a new, solid-state photoluminescence material that emits radiation in the spectroscopic range between 490 and 590 nm upon ultraviolet light excitation, with potential use as an organic light emitting diode, laser frequency harmonic generator, or photoelectric converter.As polymers play an undeniable role in our everyday lives, extensive resources and safety evaluations are devoted toward the development and marketing of the most suitable and effective polymer species for a given application , the salicylaldehyde fragment containing atom C4 (S1A) is near planar [r.m.s. deviation = 0.010 (1) Å], with a maximum out-of-plane deviation of 0.020 (2) Å for the O1 atom. Similarly, its companion salicylaldehyde fragment (S1B) is near planar [r.m.s. deviation = 0.025 (2)], with a maximum out-of-plane deviation of 0.050 (2) Å for the O3 atom. The bridge angle C4—C1—C11 measures 109.5 (2)° and the S1A and S1B planes subtend a dihedral angle of 88.4 (1)°. Molecule (1) exhibits two intramolecular hydrogen bonds between the phenolic hydrogen atoms and carboxyl O-atom acceptors  presents two near planar appendants, denoted A1 and A2 for the appendants containing C4 and C11, respectively, . Each appendant comprises a hydroxyl and two aldehyde groups. Similar to (1), the salicylaldehyde fragments with atoms C4–C9/C11/O1/O2 (S2A) or C12–C17/C18/O6/O5 (S2B) in (2) adopt a near planar geometry [r.m.s. deviation = 0.024 (1) Å for S2A and 0.036 (1) Å for S2B]. The additional carbonyl groups C10—O3 and C18—O4 on the phenyl rings are twisted slightly out of the S2A and S2B planes, respectively, as evidenced by their respective torsion angles C5—C6—C10—O3 [−2.9 (4)°] and C13—C14—C18—O4 [−179.1 (3)°]. These additional groups increase the steric hindrance between the appendants and methyl bridge groups in (2), perhaps decreasing both the bridge angle C4—C1—C12 [108.9 (2)°] and the dihedral angle between the A1 and A2 planes [88.4 (1)°] relative to (1). Molecule (2) presents two intramolecular hydrogen bonds involving the phenolic hydrogen atoms with the carboxyl O-atom acceptors (Table 21).Molecule  and (2) exhibit several intramolecular H⋯H contacts that are shorter than the sum of the H-atom van der Waals radii. These contacts occur between the methyl group H atoms and adjacent phenyl group H atoms . Superimposition of the atoms C1/C2/C3/C4/C11 of (1) with the corresponding atoms of (2) ° and the S1B and S2B planes subtending an angle of 35.1 (1)°.Both (1) along the a axis. van der Waals contacts between the O atoms and H atoms of adjacent molecules  dominate the intermolecular interactions. In addition, bifurcated contacts between atom C17 and atoms H3 and O3 of adjacent molecules  contribute to the crystal packing. As in molecule (1), O⋯H contacts play a key role in the intermolecular interactions of (2). However, unlike (1), these interactions result mostly from hydrogen bonding between the phenolic hydrogen atoms and the carboxyl oxygen atoms of adjacent molecules  Figs. 4 and 5 ▸.et al., 2016et al., 2009et al., 2012et al., 2005et al., 20173), a common chemical known also as bisphenol A,  and 5-[(3-formyl-4-hydroxyphenyl)methyl]-2-hydroxybenzaldehyde (4)  and (2) and further discussion. Molecule (3) presents a submolecular structure of the title compounds, as it only lacks the aldehyde groups found in (1) or (2). In contrast, (4) exhibits a pair of salicylaldehyde groups as (1) or (2), except that they are linked by a >CH2 bridge, instead of a >C(CH3)2 bridge.A search of the Cambridge Structural Database  crystallizes with three independent molecules in the asymmetric unit. Each molecule presents a pair of planar phenol fragments  subtending dihedral angles of 77.81 (3), 86.15 (4) and 84.34 (4)°, respectively, and respective bridge angles of 109.2 (1), 109.5 (1), and 108.1 (1)°. In general, both (1) and (2) have similar geometric parameters to (3), although their corresponding phenol groups are less planar than those of (3). This manifestation results most likely because the phenyl groups of the title compounds contain aldehyde groups in addition to the hydroxyl groups. The O atoms of these aldehyde groups participate in hydrogen bonding with the hydroxyl H atoms, thus partially displacing the hydroxyl O atoms away from the phenol planes. A superimposition of the atoms in (1) with the corresponding atoms of one of the three structures of (3) shows that the differences in the atom positions of the two structures are hardly discernible  and its counterpart of (3)]. An overlay of structure (1) onto either structure two or three of (3) yields comparable results. A similar analysis of structures (2) and (3) yields a r.m.s. deviation of 1.14 Å with maximum displacement of 0.605 (2) Å for the C6 atom of (2) and its counterpart in (3). Again, we obtain comparable results overlaying either structure two or three of (3) onto (1).Compound  exhibits a pair of near planar salicylaldehyde fragments [r.m.s. deviation = 0.0153 (2) and 0.0238 (9) Å] forming a dihedral angle of 85.96 (4)°, similar to (1). Its bridge angle of 113.6 (1)° is much greater than that of (1) or (2), however. A superimposition of the salicylaldehyde group atoms of (4)  with corresponding atoms of (1) reveals nearly identical atomic positions of the two groups [r.m.s. deviation = 0.0160 Å], with the companion salicylaldehyde group planes [centroid-to-centroid distance measuring = 4.68 (2) Å] subtending a dihedral angle of 6.81°. A similar analysis for structures (2) and (4) yields a r.m.s. deviation = 0.027 Å with companion salicylaldehyde groups planes [centroid-to-centroid distance measuring = 4.21 (1) Å] forming a dihedral angle of 7.4 (1)°.Molecule  and (2), respectively).The title compounds were synthesized following modified literature procedures (Özdemir 1): A combination of compound (3) , paraformaldehyde , and magnesium(II) chloride  were suspended in tetrahydrofuran , placed under a stream of N2, and stirred. Then, triethylamine  was added dropwise to the reaction mixture at ambient temperature and stirred under reflux for 16 h. At the conclusion of the reaction, the mixture was cooled to room temperature before the addition of diethyl ether (500 mL). The organic solution was sequentially extracted with aqueous 1 M HCl (3 × 500 mL) and water (3 × 500 mL), dried over Na2SO4 or MgSO4, filtered, and the volatiles were removed under reduced pressure. The solid residue was purified with a series of hexane washes and then dried under vacuum to afford the desired product (1) as a white solid . Slow diffusion of hexanes into a benzene solution saturated with (1) afforded single crystals of (1).Compound (2): A mixture of (3)  and hexamethylenetetramine  was dissolved in trifluoroacetic acid  under ambient conditions. The reaction mixture was stirred at 403 K for 2.5 h and subsequently cooled to room temperature before aqueous HCl  was added slowly. The reaction mixture was stirred at 383 K for 16 h, cooled to room temperature, and the resulting organic phase extracted with dichloromethane . Then, this organic phase was dried over MgSO4, filtered, and the volatiles were removed under reduced pressure. The resulting solid was purified with a series of hexanes washes and dried under vacuum to afford the novel product (2) as a neon yellow solid . Slow evaporation of a DCM solution saturated with (2) afforded single crystals suitable for X-ray diffractometry.Compound (1) 1H NMR : δ 1.70 , 6.92 , 7.35 , 7.43 , 9.86 , 10.93  ppm. 13C NMR : δ 30.47, 41.86, 117.85, 120.15, 130.92, 136.20, 141.67, 160.10, 196.74 ppm. (2) 1H NMR : δ 1.75 , 7.81 , 10.19 , 11.53  ppm. 13C NMR : δ 30.31, 30.59, 42.08, 123.05, 135.53, 141.31, 162.20, 191.99 ppm; low-resolution mass spectrometry (atmospheric pressure ionization); Thermo Fisher Scientific (ISQ–EC): m/z [M]+: calculated = 340.33; measured: 340; and luminescence spectrum (Horiba Jobin Yvon Fluoromax 3 Spectrofluorimeter): 10−5  M/acetonitrile; λexc = 356 nm; λem = 539 nm .Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker 400 MHz spectrometer. Chemical shifts (δ) are given in ppm: (1) and most in (2) were refined in a riding-model approximation with C—H = 0.93 or 0.96 Å, Uiso(H) = 1.2Ueq(C) or 1.5Ueq(Cmethyl) and O—H = 0.82 Å and Uiso(H) = 1.5Ueq(O). In (2), atoms H10, H11, H18, and H5A were refined independently with isotropic displacement parameters.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018016316/lh5885sup1.cifCrystal structure: contains datablock(s) 1, 2. DOI: 10.1107/S2056989018016316/lh58851sup4.hklStructure factors: contains datablock(s) 1. DOI: 10.1107/S2056989018016316/lh58852sup5.hklStructure factors: contains datablock(s) 2. DOI: 1879532, 1879531CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, two molecules are associated into an inversion dimer via a pair of C—H⋯π interactions. The dimers are linked by another pair of C—H⋯π interactions, forming a ribbon along the c-axis direction.In the title compound, C 27H29BrN2, the carbazole ring system is essentially planar, with an r.m.s. deviation of 0.0781 (16) Å. An intramolecular N—H⋯N hydrogen bond forms an S(6) ring motif. One of the tert-butyl substituents shows rotational disorder over two sites with occupancies of 0.592 (3) and 0.408 (3). In the crystal, two molecules are associated into an inversion dimer through a pair of C—H⋯π interactions. The dimers are further linked by another pair of C—H⋯π interactions, forming a ribbon along the c-axis direction. A C—H⋯π interaction involving the minor disordered component and the carbazole ring system links the ribbons, generating a network sheet parallel to (100).In the title compound, C Thus, the title compound has two tert-butyl groups on the carbazole moiety. The title compound is a suitable model to investigate an intramolecular hydrogen bond between the heteroaromatic N—H and the N atom of the imino group. We report herein on its molecular and crystal structures.Carbazole derivatives have been widely applied in various fields such as pharmaceuticals  Å at atom C8. There is an intramolecular N—H⋯N hydrogen bond involving the amino group (N3—H3) in the carbazole ring and an imine N atom (N2), generating an S(6) ring motif  and 0.408 (3).The molecular structure of the title compound is shown in Fig. 1f Table 1. The dihA—H22C⋯Cg1i in the major disorder component or C21B—H21E⋯Cg1i in the minor disorder component; Cg1 is the centroid of the C25–C30 ring; symmetry code as in Table 1Cg2ii; Cg2 is the centroid of the C4–C9 ring; symmetry code as in Table 1c-axis direction bis[N-methanimine]  and 4-bromoaniline  were treated in xylene (10 ml) at 423 K under inert gas overnight, followed by evaporation. The recrystallization of the residue from a solvent mixture of acetone and methanol  afforded single crystals of the title compound suitable for X-ray structure analysis . 1H NMR  δ = 1.47 , 1.49 , 7.22 , 7.47–7.58 , 7.67 , 8.13 , 8.26 , 8.72 , 10.55 . HR–MS (m/z): calculated for [C27H30BrN2]+, m/z = 461.1587; found, 461.1627.3,6-Di-Uiso(H) = 1.2Ueq(C). Orientational disorder of the tert-butyl substituent (C20–C23) around the C13—C20 bond axis is observed and the occupancies refined to 0.592 (3) and 0.408 (3).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989019012374/is5522sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989019012374/is5522Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019012374/is5522Isup3.cmlSupporting information file. DOI: 1951647CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


R)- and (S)-camphor thiosemicarbazone, which crystallizes in the centrosymmetric space group C2/c, is reported.A racemic mixture of ( R)- and (S)-camphorquinone with thiosemicarbazide yielded the title compound, C11H17N3OS [common name: (R)- and (S)-camphor thiosemicarbazone], which maintains the chirality of the methylated chiral carbon atoms and crystallizes in the centrosymmetric space group C2/c. There are two molecules in general positions in the asymmetric unit, one of them being the (1R)-camphor thiosemicarbazone isomer and the second the (1S)- isomer. In the crystal, the molecular units are linked by C—H⋯S, N—H⋯O and N—H⋯S interactions, building a tape-like structure parallel to the (R21(7) and R22(8) graph-set motifs for the H⋯S interactions. The Hirshfeld surface analysis indicates that the major contributions for crystal cohesion are from H⋯H (55.00%), H⋯S (22.00%), H⋯N (8.90%) and H⋯O (8.40%) interactions.The equimolar reaction between a racemic mixture of ( R1R2C=O group and it was pointed out that the R1R2C=N—N(H)C(=S)NH2 compound was the main product of the condensation reaction  and soft (S) donor atoms in chain  chemistry can be traced back to the beginning of the 20th century, when thiosemicarbazide was used for the chemical characterization of the et al., 2009II, ZnII and FeII/III and reducing the bioavailability of these essential metals, which impacts the growth of tumor cells  inhibition in vitro, a key biological target for cancer research - and the other the (1S)-isomer. For the first molecule, the 1R and the 4S chiral centers are labelled C2 and C5, and the thiosemicarbazone unit is nearly planar with a N1—N2—C11—N3 torsion angle of −4.7 (2)° ° ° Fig. 1. In the )° Fig. 2. The twoi, N3—H17⋯O1ii, C5—H5⋯S2i and N5—H32⋯S1iii interactions  and di (x axis) values are the closest external and internal distances  from given points on the Hirshfeld surface contacts -camphor 4-phenylthiosemicarbazone -camphor 4-phenylthiosemicarbazone. For the literature structure, the decrease of the contributions from other possible interactions is assumed to be due to the geometric impediment of the phenyl ring. The impact of steric effects on the intermolecular interactions sites can be seen in the graphical representation of the Hirshfeld surface in Fig. 9R)-camphor 4-phenyl-TSC molecules crystallize as discrete units, being connect by very weak interactions. The most frequent intermolecular interactions for the crystal cohesion of the phenyl-TSC derivative are (in %) H⋯H = 55.9, H⋯C/C⋯H = 16.8, H⋯S/S⋯H = 11.0, H⋯O/O⋯H = 7.8 and H⋯N/N⋯H = 7.0. The replacement of one H atom by the phenyl group in the terminal amine entity strongly impacts on, for example, the contribution of the intermolecular H⋯S/S⋯H interactions, which changed from 22.00% to 11.00%. Finally and remarkably, in the comparison molecule, intermolecular H⋯C/C⋯H interactions make the next highest contibution to the Hirshfeld surface; this interaction is comparatively less relevant for the title compound (4.5%).To the best of pur knowledge and from using database tools such as R- and S-camphor was oxidized with SeO2 to the respective 1,2-diketone  = 1.2Ueq and C—H bond distances of 0.98 Å for tertiary carbon atoms and 0.97 Å for secondary C atoms. The N—H bond distances are 0.86 Å. Finally, Uiso(H) = 1.5Ueq(C) for the methyl groups, with C—H bond distances of 0.96 Å. A rotating model was used for the latter H atoms.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989019016980/rz5268sup1.cifCrystal structure: contains datablock(s) I, publication_text. DOI: 10.1107/S2056989019016980/rz5268Isup2.hklStructure factors: contains datablock(s) I. DOI: 1973095CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Several O—H⋯N and N—H⋯O hydrogen-bonding interactions exist between the [Zn(H 2O)6](NO3)2·2C6H5N5, crystallizes in the space group P3− anion and one half of a [Zn(H2O)6]2+ cation (2O)6]2+ cation and the N atoms of the tetrazolide ring, and between the nitrate anions and the N—H groups of the pyridinium ring, respectively, giving rise to a three-dimensional network. The 5-(pyridinium-3-yl)tetrazol-1-ide molecules show parallel-displaced π–π stacking interactions; the centroid–centroid distance between adjacent tetrazolide rings is 3.6298 (6) Å and that between the pyridinium and tetrazolide rings is 3.6120 (5) Å.Hexaaquazinc(II) dinitrate 5-(pyridinium-3-yl)tetrazol-1-ide, [Zn(H The hexaaquazinc(II) complex exhibits regular octahedral geometry 6]X2  cocrystallized with 5-(pyridinium-3-yl)tetrazol-1-ide tetrazol-1-ide zwitterion, one NOy Table 1, and they Table 1. The geo2O)6]2+, through O—H⋯N hydrogen bonds, exhibiting D⋯A distances in the range 2.7446 (17)–2.8589 (17) Å. Additionally, the pyridinium ring is involved in N—H⋯O hydrogen bonding to nitrate atom O4, with an N⋯O distance of 2.7384 (18) Å. These interactions are shown in the crystal packing diagram  plane. These parallel-displaced π–π interactions lead to interplanar distances of 3.21 (1) and 3.10 (3) Å, and two centroid–centroid distances  complex cations and nitrate ions serves to hold the structure together Table 2. The N aam Fig. 3. The strs Table 3. The cens Table 3.baab2O)6]X2·2C6H5N5 structures, as more hexaaquazinc(II) complexes can interact with the N atoms of the tetrazole units. Parallel-displaced π–π stacking interactions occur in the title compound and in [Mg(H2O)6]X2·2C6H5N5. In [Mg(H2O)6]Cl2·2C6H5N5, the pyridinium–tetrazolide zwitterions have alternating orientations in the supramolecular arrangement, whereas in the title compound, the zwitterions are oriented in the same direction, allowing a possible coupling transition between dipole moments similar to J-aggregates  cation with a halide counter-ion [chloride  and ZnCl2 (2 mmol) were dissolved in 6 ml of distilled water. This mixture was transferred to a glass bottle and then heated at 378 K for 24 h. The pH was adjusted using a HNO3 (66%) solution immediately after mixing the reactants, and was monitored with a pH meter (pH2700 Oakton) until reaching a pH of 2.0. The reaction mixture was then cooled to 318 K and kept at this temperature for 16 h. The colourless block-shaped crystals obtained were washed with ethanol to give 353 mg (yield 30%) of the title compound.All the reactants and chemicals were purchased from Sigma Aldrich and utilized without further purification. A mixture of 3-cyanopyridine (4 mmol), NaNUiso(H) = 1.2Ueq(C). Moreover, all H atoms in the hexaaquazinc(II) complex were refined with a distance restraint of O—H = 0.85 Å and with Uiso(H) = 1.5Ueq(O).Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S205698901801112X/cq2025sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S205698901801112X/cq2025Isup3.hklStructure factors: contains datablock(s) I. DOI: 1860162CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The ergogenic effect of βA has also been demonstrated for 2000-m rowing performance prompting interest in whether βA may be beneficial for sustained aerobic exercise. This study therefore investigated the effect of two βA dosing strategies on 30-min rowing and subsequent sprint performance.− 1, βA1); ii) matched total βA ; or iii) cornflour placebo . Participants completed a laboratory 30-min rowing time-trial, followed by 3x30-seconds (s) maximal sprint efforts at days 0, 14 and 28 (T1-T3). Total distance (m), average power (W), relative average power (W·kg− 1), cardio-respiratory measures and perceived exertion were assessed for each 10-min split. Blood lactate ([La-]b mmol·L− 1) was monitored pre-post time-trial and following maximal sprint efforts. A 3-way repeated measures ANOVA was employed for main analyses, with Bonferonni post-hoc assessment (P ≤ 0.05).Following University Ethics approval, twenty-seven healthy, male rowers  were randomised in a double-blind manner to 4 weeks of: i) βA , including absolute average power  and relative average power output . These findings were potentially explained by within-group significance for the same variables for the first 10 min split (P ≤ 0.01), and for distance covered (P = 0.01) in the second 10-min split. However, no condition x time interactions were observed. No significant effects were found for sprint variables (P > 0.05) with comparable values at T3 for mean distance , average power  and lactate .Total 30-min time-trial distance significantly increased from T1-T3 within βA1 only  may be warranted based on within-group observations.Whilst daily βA may confer individual benefits, these results demonstrate limited impact of βA (irrespective of dosing strategy) on 30-min rowing or subsequent sprint performance. Further investigation of βA dosage > 2.4 g·d Following a 5-min seated period, 2-min baseline expired air samples were collected via the Douglas bag method  and anal−]b was assessed following the final collection period only.All time-trials were conducted on the same Concept 2 air braked rowing ergometer  with resistance set at 5 for standardisation. Participants undertook a self-paced, continuous warm-up at 100 W for 5-min, after which the unit display was modified to display time remaining to minimise extraneous influences on pacing strategy . Partici−]b, RPE and performance data (distance rowed (m), average power (W)) were recorded on completion of each sprint. At the mid-point of each sprint, standardised verbal encouragement was given to all participants to promote maximal engagement.Following a standardised 5-min inactive rest period, participants completed three 30-s maximal sprint efforts with 60-s inactive recovery in between. b (mmol·L− 1) , absolute VO2 (L·min− 1)  or relative VO2 (ml·kg− 1·min− 1) .Intervention groups were matched for age (yrs), rowing experience (yrs), body-height (m), body-mass (kg) and body-fat (%) at baseline Table . Non sigP = 0.22, ηp2 = 0.11). A significant effect was shown for time only , with βA1 distance increasing from 7397 ± 195 m at T1 to 7580 ± 171 m by T3 only .Data for distance rowed (m) during the 30-min time trial are shown as absolute a) and relative b) values in Fig. P = 0.05, ηp2 = 0.12) with βA1 from 194.8 ± 18.3 W (T1) to 204.2 ± 15.5 (T3) (P = 0.04). No differences were reported within group for βA2 (200.3 ± 9.8 W (T1) to 208.8 ± 8.0 W (T3); P > 0.05) or PL (173.0 ± 13.8 W (T1) to 174.8 ± 13.7 W (T3); P > 0.05). When adjusted for body-mass, average power output expressed as a) absolute and b) relative change is shown in Fig. − 1) between T1 and T3  for βA1 only . A significant between group main effect was reported , with post-hoc analysis indicating an overall difference between βA2 and PL only (P = 0.04). However, no group x time interactions were shown for absolute changes in average power to weight ratio . When data was expressed as relative change in average power, no significant between group differences were observed ; despite small improvements of 0.13 ± 0.06 W·kg− 1 for βA1 and 0.11 ± 0.05 W·kg− 1 for βA2, in contrast to negligible changes of 0.01 ± 0.06 W·kg− 1 for PL.Similarly, mean power significantly increased for time only  for βA1 only , however RPE was maintained throughout the intervention (average RPE: 7.7 ± 0.2 (T1), 7.8 ± 0.2 (T2), 7.8 ± 0.3 (T3) P > 0.05). In contrast, average RPE significantly increased by T3  for both βA2 (7.1 ± 0.5 (T1) to 7.7 ± 0.4 (T3); P = 0.04) and PL (6.5 ± 0.4 (T1) to 7.3 ± 0.03 (T3); P = 0.01). Average VO2 was maintained across all trials with no group x time interactions reported (βA1: 3.12 ± 0.12 L·min− 1 (T1) to 3.14 ± 0.10 (T3); βA2: 3.17 ± 0.10 L·min− 1 (T1) to 3.24 ± 0.14 (T3); PL: 2.93 ± 0.13 L·min− 1 (T1) to 2.86 ± 0.14 (T3); P > 0.05).Average HR significantly increased by T3 , with βA1 significantly increasing between T1-T2 (P = 0.03), T1-T3 (P = 0.004) representing a 3.65% (T1-T2) and 4.52% (T1-T3) distance increase, respectively. Likewise, βA2 also increased distance covered significantly by 2.55% from T2-T3 (P = 0.01). Accompanying these effects for distance, time effects  for absolute power was observed in βA1 only between T1-T2 (P = 0.03) and T1-T3 (P = 0.01). These represented a 14.04 and 14.61% increase in watts, respectively. Time effects  for power to weight was observed in βA1 only, between T1-T2 (P = 0.02) and T1-T3 (P = 0.01). These represented a 6.20 and 6.75% increase in W·kg− 1, respectively.No group x time interactions were shown for overall 0-10 min time trial performance  between T1 and T3  for βA1  and βA2 , but not PL (P > 0.05). In contrast, average RPE , VE , VO2 , VCO2  and RER  were maintained across all trials with no significant interactions reported.A significant effect was observed for changes in HR , with βA1 increasing distance rowed by 54 ± 14 m between T1-T3 (P = 0.01). Other performance variables such as absolute power  and power to weight  failed to reach significance overall. Average HR , VE , VO2 , VCO2 , RPE , and RER  were maintained across all trials with no significant interactions reported.No group x time interactions were shown during the second 10-min split  in distance covered or other performance variables (P > 0.05). Average HR , VE , VO2 , VCO2  RPE  and RER  were maintained across trials with no significant group x time interactions reported.No group x time interactions were shown for overall 21–30 min time trial distance covered , or time  effects were observed at any time-point for distance covered. Likewise, power , power to weight , HR , RPE  and [La-]b  failed to reach significance.No significant between-group effects existed at T1 with all groups rowing 166.0 ± 2.5 m , on 30-min rowing time trial and subsequent anaerobic sprint performance. A recent 2018 ISSN Position Stand  stated tThe findings from the current study support previous research on 10-km running performance , wherebymilieu interieur’ from homeostatic perturbations caused by supra-maximal levels of intracellular acidosis. However, whilst the current cohorts [La−]b were clearly elevated following each sprint bout, the mean [La−]b post time trial and during associated sprint efforts for βA1 were not significantly affected by βA consumption compared to PL, possibly suggesting an absence of meaningful carnosine facilitated buffering at the current dosage.Regarding the anaerobic sprint data, no significant interaction effects were observed for any variables. This was unexpected as previously Suzuki et al.  noted a − 1), it is feasible that one explanation for a lack of significant findings with βA2 may have been influenced as a result of variances in lean muscle mass.A novel aspect of this study was the inclusion of an alternate day dosing strategy . Previous research has suggested that the primary facilitator of muscle carnosine concentration is the total dose consumed, not factors such as baseline content or daily dose . The curOther reasons for variation caused by dosing may reside in the pharmacokinetics of βA, with previous research  exhibiti−]b, RPE and HR were recorded throughout the test, blood pH was not. Subsequently, it must be conceded that the capacity to assess or infer whether effects were associated with carnosine directed (pH) buffering are limited. Additionally, due to a commonly reported side effect of βA , particesthesia , 48.− 1 for four-weeks is not sufficient to maximise muscle carnosine content [− 1 of βA each day for 24 weeks, observing gene expression, muscle carnosine content and cycling capacity (CCT110%) [− 1 [Beyond the delivery method of βA, previous research demonstrated that at an average daily dose of 5.2 g·day content . More reCCT110%) . Interes0%) [− 1 ) or dura0%) [− 1  may be w− 1) for longer periods (> 28 days) should also be considered.In conclusion, regardless of dose strategy, when compared to placebo, βA does not enhance sustained aerobic performance or subsequent high intensity efforts. However, the within-group finding that daily βA use increased 30-min rowing time trial performance warrants further investigation. The inclusion of higher dosing strategies (> 2.4 g·day


In the crystal, the molecules are joined by C—H⋯O contacts into infinite chains along the  18H23FO5, was synthesized by reacting diethyl malonate with 1-(4-fluorophenyl)-3-methylbut-2-en-1-one. The molecule adopts a loose conformation stabilized by weak C—H⋯O and C—H⋯π interactions. In the crystal, the molecules are joined by C—H⋯O contacts into infinite chains along the b-axis direction with a C(6) graph-set motif. Hirshfeld surface analysis and fingerprint plots demonstrate the predominance of H⋯H, O⋯H and F⋯H intermolecular interactions in the crystal structure.The title compound, C The molecular conformation is stabilized by an intramolecular C—H⋯O hydrogen bonds and C—H⋯π interaction °; the dihedral angles formed by aromatic ring with adjacent and opposite ester groups are 56.66 (4) and 16.08 (4)°, respectively. The dihedral angle between aromatic ring and ketone carbonyl unit is 14.04 (5)°.The title compound crystallizes in the monoclinic crystal system in the space group on Fig. 1 and shorB⋯O2, which join the molecules into infinite chains with graph-set motif C(6) —CH2 and C6H4—C(=O)—CH2—CH2—CH(COO)2 gave 102 and 62 hits, respectively. Among them, two hits, (S)-ethyl-2-(4-t-butylbenzylsulfanyl)-4-(4-fluorophenyl)-4-oxobutanoate -2-(1-(4-nitrophenyl)-1,4-dioxopentan-3-yl) malonate . Single crystals of the title compound were obtained by slow evaporation from acetone solvent at room temperature.To a stirred solution of diethyl malonate  in tetrahydrofuran (5 ml), sodium hydride  was added at 273 K. The reaction mixture was allowed to stir for 15 min. A solution of 1-(4-fluorophenyl)-3-methylbut-2-en-1-one  in THF was added into the reaction mixture. The reaction mixture was then allowed to stir overnight at room temperature. The completion of the reaction was monitored by thin layer chromatography. The reaction mixture was quenched with saturated ammonium chloride and extracted with ethyl acetate (2 × 25 ml). The combined organic layer was washed with water (2 × 25 ml), brine (25 ml), dried over sodium sulfate and evaporated under reduced pressure to obtain the crude product, which was purified by column chromatography using 60–120 mesh silica gel with ethyl acetate and hexane eluent (Uiso = 1.2 or 1.5Ueq(C). The methyl groups were allowed to rotate.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989018012094/yk2116sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018012094/yk2116Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018012094/yk2116Isup3.cmlSupporting information file. DOI: 1863914CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The asymmetric unit of the title pyridiniminium halide salt comprise of one cation and one anion. In the crystal, molecules are linked by N—H⋯Br and C—H⋯O hydrogen bonds, C—H⋯π interactions, and π–π interactions into layers. The intermolecular interactions in the crystal structure are quantified by Hirshfeld surface analysis. 17H23N2O+·Br−, the adamantyl moiety and the pyridiniminium ring are inclined to the ketone bridge by torsion angles of −78.1 (2) (C—C—C=O) and 58.3 (2)° (C—C—N—C), respectively, and the ketone bridge has a C—C—C—N torsion angle of 174.80 (15)°. In the crystal, the cations are connected into chains parallel to the c axis by C—H⋯O hydrogen bonds. The chains are further linked into layers parallel to the bc plane by N—H⋯Br and C—H⋯Br hydrogen bonds, C—H⋯π interactions and π–π stacking interactions [centroid-to-centroid distance = 3.5657 (11) Å]. A Hirshfeld surface analysis, which comprises the dnorm surface, electrostatic potential map and two-dimensional fingerprint plots, was carried out to verify the contribution of the various intermolecular interactions.In the cation of the title salt, C The ketone bridge is in an antiperiplanar conformation [C1—C11—C12—N1 = 174.80 (15)°]. The dihedral angle formed by the pyrimidinium ring with the ketone bridge is 59.77 (14)°. Bond lengths and angles in the cation are within normal ranges  Å], indicating partial double-bond character. Similar bond lengths are found in related compounds with an N+=C double bond  Å].In the crystal, the cations are linked into chains along the s Table 1. The chaCrystalExplorer3.1  in the electrostatic potential map indicates hydrogen-acceptor potential, whereas the hydrogen donors are represented by positive electrostatic potential (blue region) . This observation is further confirmed by the respective electrostatic potential maps where Br1 shows negative electrostatic potential as a hydrogen acceptor . Beside those two short intermolecular contacts, the C—H⋯O and C—H⋯π interactions are shown as light-red spots on the dnorm surface . The reciprocal H⋯Br/Br⋯H and H⋯O/O⋯H interactions with 15.9% and 7.6% contributions, respectively are present as sharp symmetrical spikes at de + di ≃ 2.4 and 2.5 Å, respectively . The reciprocal H⋯C/C⋯H interactions appear as two symmetrical narrow wings at de + di ≃ 2.5 Å and contribute 7.8% to the Hirshfeld surface . The reciprocal N⋯H/H⋯N interactions appear as a symmetrical V-shaped wing in the FP map with de + di ≃ 2.7 Å and contribute 2.7% to the Hirshfeld surface . The percentage contributions for other intermolecular contacts are less than 2.6%.A quantitative analysis of the intermolecular interactions can be made by studying the fingerprint plots (FP); characteristic pseudo-symmetry wings in the FP Fig. 6. The mos Å Fig. 6b. The rly Fig. 6c and 6ece Fig. 6d. The rce Fig. 6f. The pet al., 2017et al., 2018A mixture of 1-adamantly bromomethyl ketone  and 4-aminopyridine  was dissolved in 10 ml of toluene at room temperature, followed by stirring at 358 K for 18 h. The completion of the reaction was marked by the amount of the separated solid from the initially clear and homogeneous mixture of the starting materials. The solid was filtered and washed by ethyl acetate. The final pyridiniminium salt was obtained after the solid had been dried under reduced pressure to remove all volatile organic compounds (Said Uiso(H) = 1.2Ueq(C). The N-bound H atoms were located in a difference-Fourier map and freely refined. One outlier (100) was omitted in the last cycles of refinement.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989018009131/rz5239sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018009131/rz5239Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018009131/rz5239Isup3.cmlSupporting information file. DOI: 1851334CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


A weak C—Hmethoxymethyl⋯π interaction is also observed.The title compound is built up by two dioxolo, two pyridine, one pyridazine and one pyran rings. The two dioxolo rings are in envelope conformations, while the pyran ring is in twisted-boat conformation. The pyradizine ring is oriented at dihedral angles of 9.23 (6) and 12.98 (9)° with respect to the pyridine rings, while the dihedral angle between the two pyridine rings is 13.45 (10)°. In the crystal, C—H 27H30N4O6·H2O, the two dioxolo rings are in envelope conformations, while the pyran ring is in a twisted-boat conformation. The pyradizine ring is oriented at dihedral angles of 9.23 (6) and 12.98 (9)° with respect to the pyridine rings, while the dihedral angle between the two pyridine rings is 13.45 (10)°. In the crystal, O—Hwater⋯Opyran, O—Hwater⋯Omethoxymethyl and O—Hwater⋯Npyridazine hydrogen bonds link the molecules into chains along [010]. In addition, weak C—Hdioxolo⋯Odioxolo hydrogen bonds and a weak C—Hmethoxymethyl⋯π interaction complete the three-dimensional structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (55.7%), H⋯C/C⋯H (14.6%), H⋯O/O⋯H (14.5%) and H⋯N/N⋯H (9.6%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Electrochemical measurements are also reported.In the title compound, C O-triphosphate can be used as a potential substrate for fluorescence detection and imaging of DNA pyridazine and its derivatives has been a goal of chemists in recent years. 5--2′-deoxyuridine-5′-B (O2/O3/C2–C4) and C (O4/O5/C5–C7), are in envelope conformations. Atoms O3 and O4 are at the flap positions and are displaced by 0.442 (2) and −0.397 (2) Å, respectively, from the least-squares planes of the four atoms. A puckering analysis of the pyran ring A (O1/C1/C2/C4–C6), gave the parameters QT = 0.6508 (25) Å, q2 = 0.6451 (25) Å, q3 = −0.0865 (26) Å, φ = 214.6 (2)° and θ = 97.64 (23)°, indicating a twisted-boat conformation. The pyradizine ring D (N1/N2/C14–C17) is oriented at dihedral angles of 9.23 (6) and 12.98 (9)°, respectively, to the pyridine rings E (N3/C18–C22) and F (N4/C23–C27), while the dihedral angle between the two pyridine rings is 13.45 (10)°. The methoxymethyl moiety is nearly co-planar with the pyradizine ring, as indicated by the O6—C13—C14—C15 torsion angle of −172.8 (2)°.The title molecule contains two dioxolo, two pyridine, one pyridazine and one pyran rings Fig. 1. The pyrwater⋯Opyran, O—Hwater⋯Omethoxymethyl and O—Hwater⋯Npyridazine hydrogen bonds  analysis  have a symmetrical distribution of points, Fig. 5c, with the thin and thick edges at de + di = 2.85 and 2.78 Å. The pair of characteristic wings in the fingerprint plot delineated into H⋯O/O⋯H contacts  arises from the O—H⋯O and C—H⋯O hydrogen bonds  arises from the O—H⋯N hydrogen bonds  have a wide spike with the tip at de = di = 1.75 Å.The most important interaction is H⋯H, contributing 55.7% to the overall crystal packing, which is reflected in Fig. 5s Table 1 as well s Table 1 and has ts Fig. 5e, 9.6% s Table 1 as well ts Fig. 5g, 2.4% dnorm plotted onto the surface are shown for the H⋯H, H⋯C/C⋯H, H⋯O/O⋯H and H⋯N/N⋯H interactions in Fig. 6a–d, 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⋯O/O⋯H and H⋯N/N⋯H interactions suggest that van der Waals interactions and hydrogen bonding play the major roles in the crystal packing  = [1 − Rt(HCl)/Rt(inh)] × 100, where Rt(inh) and Rt(HCl) are the charge-transfer resistances for MS immersed in HCl, with the title compound and without inhibitor. Nyquist representations of mild steel in 1 M HCl in the absence and presence of the inhibitor system are shown in Fig. 7The effect of the title compound as an inhibitor of the corrosion of mild steel (MS) were studied using electrochemical impedance spectroscopy in the concentration range of 10M HCl without and with various concentrations of the inhibitor. The impedance diagrams obtained have an almost semicircular appearance. This indicates that the corrosion of mild steel in aqueous solution is mainly controlled by a charge-transfer process. The impedance parameters are given in Fig. 8Rct is increased to a maximum value of 185 Ω cm2 for the inhibitor, showing a maximum inhibition efficiency of 91% at 10−3M. The decrease in Cdl from the HCl acid value of 200 µF cm−2, may be due to the increase in the thickness of the electrical double layer or to a decrease in the local dielectric constant  specimens in 1 et al., 2008viz. aquabiscopper(II) bis(trifluoromethanesulfonate) pyridazine]bis(μ2-azido)diazaidodicopper monohydrate]  complexes coordinated by 3,6-di(pyridin-2-yl)pyridazine ligands have been reported  was added to a solution of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (4 mmol) in toluene (20 ml). Stirring was continued at room temperature for 4 h. The solvent was removed under reduced pressure. The residue was separated by chromatography on a column of silica gel with ethyl acetate/hexane (1:2) as eluent. Colourless crystals were isolated on evaporation of the solvent (yield: 82%).6-Uiso(H) = 1.5Ueq(C-methyl) or 1.2Ueq(C) for all other H atoms.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989019009848/lh5910sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989019009848/lh5910Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019009848/lh5910Isup3.cdxSupporting information file. DOI: 1939591CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


II and CoII cations to form a polymeric complex chain propagating along the b-axis direction.The pyridine-2,6-dicarboxylate anions bridge the Ca 7H3NO4)2(H2O)4]·2H2O}n (1), the CoII ion is N,O,O′-chelated by two pyridine-2,6-dicarboxylate anions in a distorted N2O4 octahedral geometry, and two carboxylate O atoms of pyridine-2,6-dicarboxylate anions bridge tetraaquacalcium(II) units to form polymeric chains propagating along the b-axis direction. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds, and offset π–π stacking interactions [intercentroid distances = 3.551 (1) and 3.746 (1) Å] involving inversion-related pyridine rings link the polymeric chains and lattice water molecules to form a supramolecular three-dimensional framework.In the crystal of the title polymeric complex, {[CoCa(C Firstly, the O and N atoms in these ligands made them easy to chelate or bridge metal ions. Secondly, they can be completely or partially deprotonated to generate Hpdc− or pyc2−, displaying a variety of coordination modes. As a part of our ongoing studies on heterometallic frameworks, we describe here the synthesis and crystal structure of the title complex,1The controllable synthesis of heterometallic polymers, with their fascinating structures and outstanding properties, is still a challenge in crystal engineering  Å, interplanar distance = 3.309 (1) Å, slippage = 1.755 Å; Cg6⋯Cg6viii = 3.551 (1) Å, interplanar distance = 3.279 (1) Å, slippage = 1.363 Å; Cg5 and Cg6 are the centroids of pyridine rings N1/C1–C5 and N2/C8–C12, respectively; symmetry codes: (vii) −x + 1, −y + 1, −z; (viii) −x + 1, −y, −z + 1.In the crystal of k Table 2. Within et al., 2016+ and seven Na+, but no alkali earth metal heterometallic coordination polymers. Hence, the title compound 1 is the first reported heterometallic coordination polymer involving the ligand pyridine-2,6-dicarboxylic acid, CoII and an alkali earth metal (CaII).A search of the Cambridge Structural Database , Co(CH3COO)2·4H2O  and CaCl2  in 15 ml of distilled H2O was stirred for 10 min in air. 0.5 M NaOH was added dropwise and the mixture was turned into a Parr Teflon-lined stainless steel vessel and heated at 423 K for 3 d. Blue [purple in CIF?] block-shaped crystals of 1 were obtained in a yield of 70% .A mixture of HUiso(H) = 1.5Ueq(O). C-bound H atoms atoms were included in calculated positions and refined as riding: C—H = 0.93 Å with Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018007120/xu5921sup1.cifCrystal structure: contains datablock(s) 1, global. DOI: 1832782CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, the molecules are linked by N—H⋯O hydrogen bonds into supramolecular chains propagating along the [101] direction. 16H20N2O6S2, the mid-point of the C—C bond of the central ethane moiety is located on a twofold rotation axis. In the crystal, molecules are linked by N—H⋯O hydrogen bonds into supramolecular chains propagating along the [101] direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (43.1%), O⋯H/H⋯O (40.9%), C⋯H/H⋯C (8.8%) and C⋯C (5.5%) interactions.In the molecule of the title compound, C These effective drug molecules have an important role in the medical field, including as promising chemotherapeutic agents, and have been used in the treatment of many bacterial infections due to their physical, chemical and biological properties ]bis(4-methylbenzenesulfonamide).Sulfonamides are synthetic molecules which include the SO2vC (mm2) (H atoms excluded), with the twofold rotation axis bisecting the central C1—C1i bond. The molecule is Z-shaped with the N1—S1—C2—C3 torsion angle being −60.6 (3)°. The C1—O1 bond length of 1.429 (3) Å and the O1—N1 bond length of 1.426 (2) Å are close to the values reported for similar compounds (see the Database survey). The S1—O2 and S1—O3 distances are 1.4376 (17) and 1.4168 (19) Å, respectively while the S1—N1 and S1—C2 distances are 1.647 (3) Å and 1.747 (3) Å, respectively.The molecular structure of the title compound is illustrated in Fig. 13, ca 5% of the unit-cell volume.The crystal packing of the title compound features intermolecular N—H⋯O hydrogen bonds Table 1, which cet al., 2016S,2S,4S,5S)-2,5-bis[(p-toluenesulfonyl)amino]bicyclo(2.2.1)heptane amino]-1-thiohexitol -1-(toluenesulfonylamido)-3-(toluenesulfonylamidomethyl)-3,5,5-trimethylcyclohexane   surface resolution with the three-dimensional dnorm surfaces mapped over a fixed colour scale of −0.464 (red) to 2.052 (blue) Å using the CrystalExplorer  points associated with hydrogen atoms. It is characterized by an end point that points to the origin and corresponds to di = de = 1.08 Å, which indicates the presence of the H⋯H contacts in this study (43.1%). The C⋯H/H⋯C plot in Fig. 7vice versa. There are two symmetrical wings on the left and right sides (8.8%). Furthermore, there are C⋯C (5.5%), N⋯H/H⋯N (1.4%), O⋯C/C⋯O (0.1%) and S⋯H/H⋯S (0.1%) contacts in the title structure.The H⋯H plot shown in Fig. 7A view of the three-dimensional Hirshfeld surface of the title compound plotted over electrostatic potential energy in the range −0.095 to 0.123 a.u. using the STO-3G basis set at the Hartree–Fock level of theory is shown in Fig. 8The title compound was synthesized according to the method of Bauer & Suresh 1963. Single Uiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms. The NH H atom was located in a difference-Fourier maps and freely refined.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989018017437/xu5951sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018017437/xu5951Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018017437/xu5951Isup3.cmlSupporting information file. DOI: 1884045CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, the molecules are connected by weak intermolecular C—H⋯O and C—H⋯F hydrogen bonds into sheets parallel to (104). Weak intermolecular π–π interactions also occur.The molecular structure of the title chalcone derivative is nearly planar and the molecule adopts a  15H10FNO3, is nearly planar and the molecule adopts a trans configuration with respect to the C=C double bond. The nitro group is nearly coplanar with the attached benzene ring, which is nearly parallel to the second benzene ring. In the crystal, molecules are connected by pairs of weak intermolecular C—H⋯O hydrogen bonds into inversion dimers. The dimers are further linked by another C—H⋯O hydrogen bond and a C—H⋯F hydrogen bond into sheets parallel to (104). π–π interactions occur between the sheets, with a centroid–centroid distance of 3.8860 (11) Å. Hirshfeld surface analysis was used to investigate and quantify the intermolecular interactions.The molecular structure of the title chalcone derivative, C This non-linearity leads to frequency-mixing processes , the optical Kerr effect para-substituted phenyl rings and an enone connecting bridge °. The C7=O3 carbonyl group adopts an s-cis configuration with respect to the C8=C9 double bond as indicated by O3—C7—C8—C9 torsion angle of −0.8 (3)°. The molecule (excluding H atoms) is nearly planar with a maximum deviation of 0.103 (2) Å at atom O1 of the terminal nitro group. The nitro group is nearly coplanar with the attached C1–C6 benzene ring as indicated by the small dihedral angle of 7.9 (2)°. The C1–C6 and C10–C15 benzene rings make a small dihedral angle of 4.27 (8)° with each other.The asymmetric unit of the title chalcone derivative consists of a unique molecule, containing two ge Fig. 1. The molA⋯O3ii; symmetry code as in Table 1A⋯O1iii and C4—H4A⋯F1i; Table 1Cg1⋯Cg1iv,v and Cg2⋯Cg2iv,v = 3.8860 (11) Å, where Cg1 and Cg2 are the centroids of C1–C6 and C10–C15 benzene rings, respectively; symmetry codes: (iv) x − 1, y, z; (v) x + 1, y, z] ] correspond to the C11—H11A⋯O3 hydrogen bond. The C4—H4A⋯F1 and C15—H15A⋯O1 hydrogen bonds are indicated as two pairs of lighter red spots on the dnorm surface. The H12A⋯F1 contact, with its H⋯F distance shorter than the sum of van der Waals radii by 0.01 Å, appears as two tiny red spots on the dnorm surface. The donor and acceptor of a hydrogen bond with positive and negative electrostatic potentials, respectively, are represented as blue and red regions on the Hirshfeld surface mapped with electrostatic potential [Fig. 4b)]. The electrostatic potential of the F atom is less negative as compared to the O atoms of nitro and carbonyl groups, as indicated by the lighter red region. The H⋯O/O⋯H contacts are the most populated contacts and contribute 30.2% of the total intermolecular contacts, followed by H⋯H (20.6%), H⋯C/C⋯H (18.0%), H⋯F/F⋯H (13.1%) and C⋯C (10.1%) contacts -1-(4-nitrophenyl)-3-phenylprop-2-en-1-one -3-(4-fluorophenyl)-1-phenylprop-2-en-1-one  and 4-fluorobenzaldehyde  were dissolved in methanol (20 ml). A catalytic amount of NaOH was added to the solution dropwise with vigorous stirring. The reaction mixture was stirred for about 6 h at room temperature. The progress of the reaction was monitored by TLC. The formed crude product was filtered, washed repeatedly with distilled water and recrystallized from ethanol to obtain the title chalcone derivative. Yellowish single-crystals suitable for X-ray diffraction were obtained from an acetone solution by slow evaporation at room temperature.Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989018017450/is5506sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018017450/is5506Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018017450/is5506Isup3.cmlSupporting information file. DOI: 1036743CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, inversion-related molecules form dimers through intermolecular N—H⋯O hydrogen bonds with the dimers associated along the  20H17N3O3 , is built up from a benzodiazepine ring system linked to pyridyl and pendant dihydropyran rings, where the benzene and pyridyl rings are oriented at a dihedral angle of 43.36 (6)°. The pendant dihydropyran ring is rotationally disordered in a 90.899 (3):0.101 (3) ratio with the orientation of each component largely determined by intramolecular N—HDiazp⋯ODhydp (Diazp = diazepine and Dhydp = dihydropyran) hydrogen bonds. In the crystal, molecules are linked via pairs of weak intermolecular N—HDiazp⋯ODhydp hydrogen bonds, forming inversion-related dimers with R22(26) ring motifs. The dimers are further connected along the b-axis direction by π–π stacking interactions between the pendant dihydropyran and pyridyl rings with centroid–centroid distances of 3.833 (3) Å and a dihedral angle of 14.51 (2)°. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (50.1%), H⋯C/C⋯H (17.7%), H⋯O/O⋯H (16.8%), C⋯C (7.7%) and H⋯N/N⋯H (5.3%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing.The title compound, C In fact, many 1,5-benzodiazepines are best known to possess biologically diverse activities such as anti-inflammatory, hypnotic, anti-HIV-1, anticonvulsant and antimicrobial (Roma A (C1–C6) is oriented at a dihedral angle of 43.36 (6)° with respect to the pyridyl ring C (N3/C10–C14). The pendant dihydropyran ring D (O1/C15–C19) shows a 90.899 (3):0.101 (3) disorder with the minor component rotated by 174.6 (4)° from the orientation of the major component. The orientation of both components is largely determined by intramolecular N2—H2A⋯O2 or N2—H2A⋯O3A hydrogen bonds (Table 1D gave the parameters Q = 0.127 (2) Å, θ = 108.0 (8)° and φ = 79.6 (8)° while for the seven-membered diazepine ring B (N1/N2/C1/C6–C9), the parameters are Q(2) = 0.8888 (13) Å, Q(3) = 0.2070 (13) Å, φ(2) = 201.03 (8)° and φ(3) = 293.9 (4)°.The title compound, (I)s Table 1. A puckeDiazp⋯ODhydp (Diazp = diazepine and Dhydp = dihydropyran) hydrogen bonds  = 3.833 (3) Å with a dihedral angle of 14.51 (2)°; Cg1 and Cg2 are the centroids of rings D (O1/C15–C19) and C (N3/C10–C14), respectively].In the crystal, the molecules are linked via pairs of weak intermolecular N—Hs Table 1, formingon Fig. 2 by π–π-sCrystalExplorer17.5 , and those delineated into H⋯H, H⋯C/C⋯H, H⋯O/O⋯H, C⋯C, H⋯N/N⋯H, N⋯C/C⋯N, O⋯C/C⋯O, N⋯N, N⋯O/O⋯N and O⋯O contacts –(k), respectively, together with their relative contributions to the Hirshfeld surface. H⋯H interactions are the most important, contributing 50.1% to the overall crystal packing, and are shown in Fig. 5b) as widely scattered points of high density because of the large hydrogen content of the molecule. The two pairs of thin and thick spikes with the tips at de + di ∼2.27 and 1.95 Å, respectively, in Fig. 5b) are due to the short interatomic H⋯H contacts (Table 2c), with the tips at de + di ∼2.82 Å. The two pairs of thin and thick spikes with the tips at de + di = 2.67 and 2.40 Å, respectively, in Fig. 5d) are due to the N—H⋯O hydrogen bonds (Table 1e)] contacts contribute 7.0% to the HS and have symmetrical distribution of points, with the tips at de + di = 3.24 Å. The pair of characteristic wings in the fingerprint plot delineated into H⋯N/N⋯H contacts  has a pair of spikes with the tips at de + di = 1.49 Å. Finally, the N⋯C/C⋯N contacts [Fig. 5g)] contribute 1.5% to the HS and are viewed as a symmetrical distribution of points with pairs of thin edges at de + di = 3.36 Å.In order to visualize the intermolecular interactions in the crystal of the title compound, a Hirshfeld surface (HS) analysis –(e), 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⋯O/O⋯H and H⋯N/N⋯H interactions suggest that van der Waals interactions and hydrogen bonding play the major roles in the crystal packing (Hathwar To a suspension of 3-[1-(2-aminophenylimino)ethyl]-4-hydroxy-6-methylpyran-2-one (4 mmol) in ethanol (40 ml) were added 1.5 equivalents of 2-pyridinecarboxaldehyde and three drops of trifluoroacetic acid (TFA). The mixture was refluxed for 4 h. Cooling to room temperature induced the precipitation of a yellow solid, which was filtered off and washed with 20 ml of cold ethanol. Cooling to room temperature induced the precipitation of a yellow solid, which was filtered and washed with 20 ml of cold ethanol. Crystals suitable for X-ray analysis were obrained by recrystallization of the product from ethanol solution.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018017565/lh5888sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989018017565/lh5888Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018017565/lh5888Isup3.cdxSupporting information file. DOI: Click here for additional data file.10.1107/S2056989018017565/lh5888Isup4.cmlSupporting information file. DOI: 1884597CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


TS3, have been confirmed by resonant scattering. The roles of the water molecules and the C—H⋯π interactions in the crystal packing are highlighted.The absolute configurations of the 10 asymmetric carbons involved in the structure of the title limonoid,  26H28O5·0.5H2O (TS3) oxirenocyclopentaphenanthrofuran-3(3aH)-one hemihydrate], crystallizes with two independent molecules (1 and 2) in the asymmetric unit and one water molecule. TS3 is composed of three six-membered rings , three five-membered rings  and two epoxide rings. A group of five fused rings (A–E) is bonded to a furan ring (F) with a Csp3—Csp2 bond [1.500 (3) Å in molecule 1 and 1.499 (3) Å in molecule 2]. The absolute structures of the molecules in the crystal were determined by resonant scattering; Flack parameter = 0.05 (5). In the crystal, the individual molecules stack in columns along the b-axis direction. The water molecule bridges molecules 1 and 2 via Owater—H⋯O and C—H⋯Owater hydrogen bonds. Together with further C—H⋯O hydrogen bonds, linking molecules 1 and 2, the columns are linked to form slabs parallel to the ab plane. Within each column, molecules are also linked via C—H⋯π interactions involving the five-membered furan (F) rings.The title limonoid compound, C Rings A to E are fused (first compartment), while ring F is bonded to this first moiety by a Csp3—Csp2 bond, [C15—C19 = 1.500 (3) Å and C15B—C19B = 1.499 (3) Å], as shown in Fig. 1As previously reported, using one- and two-dimensional NMR techniques in combination with high-resolution mass spectroscopy studies /0.672 (2) Å for atoms C11/C11B and by 0.654 (2)/0.670 (2) Å for atoms C16/C16B. The six-membered ring C has a half-chair conformation in both molecules; the puckering parameters for molecule 1 are amplitude Q = 0.474 (2) Å, θ = 131.7 (2)° and φ = 40.9 (3)°, while for molecule 2 Q = 0.479 (2) Å, θ = 127.5 (2)°, φ = 42.9 (3)°. The five-membered rings B and E have envelope conformations with atoms C4/C4B and C15/C15B, respectively, as the flaps, being displaced from the mean plane of the other four atoms by 0.689 (2)/0.702 (2) Å and 0.526 (2)/0.454 (2) Å, respectively. The furan rings (F), are planar in both molecules.The six-membered rings TS3 comes from ten asymmetric carbon atoms , refined using Cu Kα radiation.The chirality of TS3, and details are given in Table 1via three weak hydrogen bonds  present in the structure of ds Fig. 3. The indt Table 1, stabilit Table 1 are linket al., 2016TS3 gave no hits. The moieties having the rings E and F have been seen in three cytotoxic limonoids, viz. aphanastatine, amoorastatine and hydroxyl-12-ammorastatine , but having different substituents, are known. Most of these compounds are reported as hemisynthesis products, while TS3 was obtained from a natural source.A search in the Cambridge Structural Database  and needle-like crystals, suitable for single crystal X-ray diffraction analysis, were obtained by slow evaporation of the solvents at room temperature after three days.The title compound was isolated from the root bark of  al. 2016. A smallUiso(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 210.1107/S2056989018009775/su5448sup1.cifCrystal structure: contains datablock(s) I, Global. DOI: 10.1107/S2056989018009775/su5448Isup2.hklStructure factors: contains datablock(s) I. DOI: 1854616CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the title molecule, di-methylhydroxy and 4-nitrobenzene groups cap a central di-substituted acetylene residue. The extended structure features flattened, hexameric clusters sustained by hydroxy-O—H⋯O(hydroxy) hydrogen bonds. 11H11NO3, is capped at either end by di-methylhydroxy and 4-nitrobenzene groups; the nitro substituent is close to co-planar with the ring to which it is attached [dihedral angle = 9.4 (3)°]. The most prominent feature of the molecular packing is the formation, via hydroxy-O—H⋯O(hydroxy) hydrogen bonds, of hexameric clusters about a site of symmetry 6 synthons and have the shape of a flattened chair. The clusters are connected into a three-dimensional architecture by benzene-C—H⋯O(nitro) interactions, involving both nitro-O atoms. The aforementioned interactions are readily identified in the calculated Hirshfeld surface. Computational chemistry indicates there is a significant energy, primarily electrostatic in nature, associated with the hydroxy-O—H⋯O(hydroxy) hydrogen bonds. Dispersion forces are more important in the other identified but, weaker intermolecular contacts.The di-substituted acetylene residue in the title compound, C The aggregates are disposed about a site of symmetry b). The crystal also features weak benzene-C—H⋯O(nitro) interactions, involving both nitro-O atoms. In essence, one nitro group of one molecule forms two such interactions with two symmetry-related molecules to form a supramolecular chain along the c-axis direction with helical symmetry (31 screw axis), Fig. 3a). An end-on view of the chain is shown in Fig. 3b). These weak benzene-C—H⋯O(nitro) interactions serve to link the six-molecule aggregates into a three-dimensional architecture, Fig. 4The spectacular feature of the molecular packing of (I)et al., 2019Crystal Explorer 17 , the donors and acceptors of O—H⋯O hydrogen bond involving the atoms of the hydroxyl group are characterized as bright-red spots. The faint-red spots near the phenyl-H10, H11 and nitro-O2, O3 atoms on the dnorm-mapped Hirshfeld surface in Fig. 5b) represent the effect of weak C—H⋯O interactions as listed in Table 1a), the C—H⋯π/π⋯H—C contacts listed in Table 2b) is an indication of the π–π stacking interaction between them .The Hirshfeld surface calculations for (I)a), and those delineated into H⋯H, O⋯H/H⋯O, C⋯H/H⋯C and C⋯C contacts –(e), respectively, and provide more information on the influence of short interatomic contacts upon the molecular packing. The percentage contributions from the different interatomic contacts to the Hirshfeld surface are summarized in Table 3de + di ∼1.8 Å in the fingerprint plot delineated into O⋯H/H⋯O contacts, Fig. 8c), are due to the presence of the O—H⋯O hydrogen bond, whereas the points corresponding to comparatively weak intermolecular C—H⋯O interactions, Table 1C atom and the benzene (C6–C11) ring, results in short interatomic C⋯H/H⋯C contacts, Table 2a), and by the pair of forceps-like tips at de + di ∼2.8 Å in Fig. 8d). The points corresponding to other such short interatomic contacts involving the acetylene-C5 and methyl-C3—H3c atoms at longer separations are merged within the plot. The arrow-shaped distribution of points around de + di ∼3.6 Å in the fingerprint plot delineated into C⋯C contacts, Fig. 8e), indicate π–π overlap between symmetry-related benzene (C6–C11) rings, as illustrated in Fig. 7b). The small percentage contributions from the other interatomic contacts listed in Table 3The overall two-dimensional fingerprint plot for (I)Eele), polarization (Epol), dispersion (Edis) and exchange-repulsion (Erep) terms after applying relevant scale factors ρ(r), where ρ is the electron density and λ2 is the second eigenvalue of the Hessian matrix of ρ. Crucially, through a three-colour scheme, a specific interaction can be identified as being attractive or otherwise. Thus, a green isosurface indicates a weakly attractive interaction whereas a blue isosurface indicates an attractive interaction; a repulsive interaction appears red. The isosurfaces for three identified intermolecular interactions are given in the upper view of Fig. 10a), a green isosurface is apparent for the conventional hydroxy-O—H⋯O(hydroxy) hydrogen bond. Similarly, green isosurfaces are seen between the interacting atoms involved in the phenyl-C—H⋯O(nitro), Fig. 10b), and the methyl-C—H⋯π(C11–C16), Fig. 10c), interactions.Non-covalent interaction plot (NCIplot) analyses provide a visual representation of the nature of the contact between specified species in crystals (Johnson versus sign(λ2)ρ(r). The non-covalent interaction peaks appear at density values less than 0.0 atomic units, consistent with their being weakly attractive interactions.The lower views of Fig. 10et al., 2010et al., 2016P21/c to form a hexameric clusters via hydroxy-O—H⋯O(hydroxy) hydrogen bonds as seen in (I)a); intramolecular hydroxy-O—H⋯O(carbonyl) hydrogen bonds are also apparent. In (III), the two independent molecules comprising the asymmetric unit associate about a centre of inversion in space group P21/n into a supramolecular dimer via pairs of hydroxy-O—H⋯O(hydroxy) and hydroxy-O—H⋯N(cyano) hydrogen bonds as shown in Fig. 11b). In this case, one independent hydroxy-oxygen atom and one cyano-nitrogen atom do not accept a hydrogen-bonding interaction. Three crystallographically independent molecules are also found in (II) (space group Pca21) and these self-associate to form a supramolecular chain via hydroxy-O—H⋯O(hydroxy) hydrogen bonds with non-crystallographic threefold symmetry, Fig. 11c). Finally, zigzag supramolecular chains sustained by hydroxy-O—H⋯O(hydroxy) hydrogen bonds are found in the crystal of (IV), Fig. 11d) in space group Pbca.There are four literature precedents for (I)et al., 19981H NMR : δ = 8.16 , 7.54 , 2.24  and 1.63  ppm. 13C NMR : δ = 147.2, 132.5, 129.8, 123.6, 99.2, 80.5, 66.7 and 31.3 ppm. Irregular colourless crystals of (I)The title compound was prepared as per the literature procedure (Bleicher Uiso(H) set to 1.2–1.5Ueq(C). The O-bound H atom was refined with a distance restraint of 0.82±0.01 Å, and with Uiso(H) = 1.5Ueq(O).Crystal data, data collection and structure refinement details are summarized in Table 610.1107/S2056989019010284/hb7841sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989019010284/hb7841Isup2.hklStructure factors: contains datablock(s) I. DOI: 1941466CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The manganese compound crystallized in the monoclinic space group 1/nP2 and exists as a centrosymmetric dimer.The title compound was prepared by a template method starting from manganese(II) nitrate with a Schiff base ligand. The product of condensation was between methyl carbazate and glyoxylic acid, and formed  2(C4H5N2O4)2(NCS)2(H2O)4]·4H2O (I), exists as a centrosymmetric dimer. Each dimeric unit consists of tridentate -chelating Schiff bases with symmetry-maintained μ-O-bridged carboxylate anions, terminally bound thiocyanate anions, and ligated and solvated water molecules. The complex exhibits a distorted octahedron geometry and the centrosymmetric μ-O-bridged carboxylate anions connect the two manganese atoms to form an M2O2 ring. In the crystal, the molecules are interlinked via strong N—H⋯O and O—H⋯O hydrogen-bonding contacts and weak O—H⋯S intermolecular interactions, forming a three-dimensional molecular network.The title compound, [Mn Among them, carbazates  are interesting as ligands in view of their variety of potential donor atoms such as oxygen and nitrogen. Interestingly, these neutral molecules can be expected to exhibit only one common coordination mode, i.e. N,O-chelating bidentate. This has been clearly observed in many metal complexes with a variety of anions such as formate benzaldehyde with ethyl carbazate  and the N-bonded NCS anion, whereas the μ-O-bridged carboxylate anions, azomethine nitrogen atom and a coordinated water molecule (O1W) occupy the equatorial positions. The two manganese atoms are connected via centrosymmetrically related μ-O-bridged carboxylate anions, forming a rhomboidal Mn2O2 unit about an inversion centre.The manganese title compound crystallizes in the monoclinic space group er Fig. 1. The asyO-bridged carboxylate anions are 2.1448 (9), 2.1905 (9) and 2.2606 (8), 2.2985 (8) Å, respectively. The Mn—N—C—S torsion angle in the NCS moiety is 103.5 (4)° and the bond angles for the coordinated atoms vary from 68.99 (3)–132.57 (4)°, indicating a distorted geometry.The separation of the Mn atoms is 3.645 (3) Å. The Mn—N(isothiocyanato) and Mn—N(azomethine) distances are 2.1289 (11) and 2.3388 (10) Å and the Mn—O distances involving the coordinated water molecules and μ-N⋯O2v [2.7971 (13) Å] hydrogen bond between adjacent dimers forms chains extending along the ac diagonal. The weak O4W—H4W1⋯S1iv interaction [3.3159 (12) Å] and O2W—H2W1⋯O4W hydrogen bond [2.7322 (14) Å] link the dimers, generating a two-dimensional network as shown in Fig. 2W, O3W and O4W are involved in O—H⋯O hydrogen-bonding interactions , 3206 (b) [ν(N—H)], 2096 (s) [ν(C≡N)], 1705 (s) [ν [νasym (C=O)], 1555 (s) [ν(C=N)], 1397 (s) [νsym(C=O)], 1067 (s) [ν(N—N)].Stoichiometric quantities of glyoxylic acid , ethylcarbazate  and ammonium thiocyanate  were dissolved in 30 mL of double-distilled water. To this homogeneous solution, Mn values were set to a multiple of Ueq(C) with 1.5 for CH3 and 1.2 for C—H groups, respectively. Positions and Uiso values of water and amine H atoms were freely refined.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989018014871/jj2203sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018014871/jj2203Isup2.hklStructure factors: contains datablock(s) I. DOI: 1870123CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The reaction of 2-methylthio-5-amino-1,3,4-thiadiazole with copper(II) acetate monohydrate resulted in the formation of the title binuclear compound 3H5N3S2) with copper(II) acetate monohydrate  resulted in the formation of the title binuclear compound, [Cu2(C2H3O2)4(C3H5N3S2)2] or [Cu2(OAc)4(Me-SNTD)2]. The structure has triclinic (PR22(12) ring motif. The molecules are further linked by C—H⋯π interactions between the thiadiazole rings and the methyl groups of the acetate units.The reaction of 2-methylthio-5-amino-1,3,4-thiadiazole (Me-SNTD; C The Cu—O bond lengths range from 1.962 (2) to 2.001 (2) Å and the Cu—N distance is 2.180 (3) Å. The Cu⋯Cu distance is 2.6727 (6) Å and each metal atom exhibits a Jahn–Teller-distorted octahedral geometry. The observed Cu—O2 bond length of 1.983 (2) Å is longer than the Cu—O1 distance of 1.962 (2) Å. The elongation of this Cu—O distance may be due to the intramolecular N3—H⋯O2 hydrogen bond (Table 1Each copper atom is displaced by 0.754 (3) Å from the plane defined by basal-plane atoms O1, O2, O3 and O4 towards the nitrogen atom, N2. The Cu1d Table 1. The coni hydrogen bond, forming a six-membered ring. The dimers are connected through an intermolecular N3—H3⋯O4ii hydrogen bond between the NH (Me-SNTD) and the carboxylate groups, forming chains propagating parallel to [001]. The above-mentioned hydrogen bonds give rise to π interactions between the thiadiazole rings and the acetate methyl groups generate a three-dimensional supramolecular framework s Table 1. Additiork Fig. 3.et al., 20162(OAc)4L2], where L is a ligand with an oxygen or nitrogen ligator atom, have been well explored. The structures of 2-methylthio-5-amino-1,3,4-thiadiazole and a complex of this molecule with cadmium have been deposited in the CSD [XUVPEK  and 2-methylthio-5-amino-1,3,4-thiadiazole  were dissolved separately in a mixture of methanol-dichloromethane , mixed together and stirred for 1.5 h. The green solid that precipitated was dissolved in methanol to form a green solution. Single crystals of the complex suitable for X-ray analysis were obtained by slow evaporation of the solution over a period of 10 d.Cu(OAc)Uiso(H) = 1.5Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989019010272/cq2032sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019010272/cq2032Isup2.hklStructure factors: contains datablock(s) I. DOI: 1941461CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


This is correlated with the formation of carboxylic acid inversion dimers linked by pairwise O—H⋯O hydrogen bonds in the crystal of the title compound rather than an intramolecular O—H⋯O hydrogen bond.The –COOH group of the title compound adopts a  11H8F3NO3, adopts a cis configuration across the –C=C– double bond in the side chain and the dihedral angle between the phenyl ring and side chain is 47.35 (1)°. The –COOH group adopts a syn conformation (O=C—O—H = 0°), unlike the anti conformation observed in related maleamic acids. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds are connected via N—H⋯O hydrogen bonds and C—H⋯O interactions into (100) sheets, which are cross-linked by another C—H⋯O interaction to result in a three-dimensional network. The Hirshfeld surface fingerprint plots show that the highest contribution to surface contacts arises from O⋯H/H⋯O contacts (26.5%) followed by H⋯F/F⋯H (23.4%) and H⋯H (17.3%).The title molecule, C This disparity is a result of O—Hc⋯O=Ca  intramolecular hydrogen bonds present in related structures and not observed in (I)The molecule of (I)in Fig. 1, similarvia pairwise O2—H2O⋯O3 hydrogen bonds  chains  chain in its own right  chains runs down the b-axis direction, thereby cross-linking the sheets into a three-dimensional network.In the crystal of (I)ds Fig. 2 forming ns Fig. 2, resultins Fig. 2. The N1—ht Fig. 2. In addiht Fig. 2 forming dnorm surfaces and two-dimensional fingerprint plots (FP) were generated to further investigate the intermolecular interactions in (I)et al., 2017N and H2O hydrogen atoms are due to their involvement as donors in stronger hydrogen bonds, while faint spots near H8 and H9 atoms are due to the weak C—H⋯O interactions involving these atoms , F⋯H/H⋯F , H⋯H , C⋯H/H⋯C , C⋯F/F⋯C  and F⋯F  interactions, with other contacts contributing the remaining 10.2%.In the Hirshfeld surface analysis, ms Fig. 3. Analysims Fig. 3 showed tN-(aryl)-maleamic acids have been reported to date with varied substituents  on the phenyl ring. Three of these, namely N-(phenyl)maleamic acid (CCDC refcode: LOSJUZ) maleamic acid (QUYJUQ) maleamic acid (PILVAI) anti O=C—O—H conformation and an intramolecular O—H⋯O hydrogen bond, as noted above. In LOSJUZ, adjacent molecules are linked by N—H⋯O hydrogen bonds into a flat ribbon, while in QUYJUQ, N—H⋯O hydrogen bonds link the molecules into zigzag chains propagating parallel to [001] and these chains are further linked into sheets by weak π–π interactions. In the crystal structure of PILVAI, symmetry-related molecules are linked by N—H⋯N hydrogen bonds, forming centrosymmetric amine–amide dimers. The dimers are linked by N—H⋯O and C—H⋯O hydrogen bonds and weak N—H⋯π and π–π interactions into a three-dimensional network.Nineteen N-(2-methylphenyl)maleamic acid  set to 1.2Ueq(C). The oxygen- and nitrogen-bound H atoms were located from difference-Fourier maps and freely refined.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989019006509/hb7816sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019006509/hb7816Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019006509/hb7816Isup3.cmlSupporting information file. DOI: 1914411CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


I centre within a S4 donor set. The three-dimensional molecular packing is sustained by amine-N—H⋯S(thione), N—H⋯N(triazolyl) and N—H⋯N(thiocyanate) hydrogen bonds.The centrosymmetric binuclear complex features a tetrahedral Ag H-1,2,4-triazole-5(4H)-thione-κ2S:S]bis{(thiocyanato-κS)silver(I)}, [Ag2(SCN)2(C2H3N3S)4], is generated by crystallographic inversion symmetry. The independent triazole-3-thione ligands employ the exocyclic-S atoms exclusively in coordination. One acts as a terminal S-ligand and the other in a bidentate (μ2) bridging mode to provide a link between two AgI centres. Each AgI atom is also coordinated by a terminal S-bound thiocyanate ligand, resulting in a distorted AgS4 tetrahedral coordination geometry. An intramolecular N—H⋯S(thiocyanate) hydrogen bond is noted. In the crystal, amine-N—H⋯S(thione), N—H⋯N(triazolyl) and N—H⋯N(thiocyanate) hydrogen bonds give rise to a three-dimensional architecture. The packing is consolidated by triazolyl-C—H⋯S(thiocyanate), triazolyl-C—H⋯N(thiocyanate) and S⋯S [3.2463 (9) Å] interactions as well as face-to-face π–π stacking between the independent triazolyl rings [inter-centroid separation = 3.4444 (15) Å]. An analysis of the calculated Hirshfeld surfaces shows the three major contributors are due to N⋯H/H⋯N, S⋯H/H⋯S and C⋯H/H⋯C contacts, at 35.8, 19.4 and 12.7%, respectively; H⋯H contacts contribute only 7.6% to the overall surface.The complete molecule of the binuclear title complex, bis[μ-1 I complex, (I)H-1,2,4-triazole-5(4H-thione) and thiocyanate ligands has been synthesized and its crystal and molecular structures determined as part of our on-going studies in this area , the heterocyclic ligand in (I)et al., 201812(SCN)]2 (I)P21/n and is disposed about a crystallographic centre of inversion. The HtrzSH molecules only employ their exocyclic thione-sulfur atoms in coordination, there being no Ag⋯N contacts of note. Each AgI atom is coordinated by a terminally bound HtrzSH molecule and by two thione-sulfur atoms derived from two μ2-bridging HtrzSH molecules. The coordination of each AgI atom is completed by a terminal, S-bound thiocyanate anion. The geometry around the silver centre defined by the S4 donor set is distorted tetrahedral with the S—Ag—S bond angles spanning about 25°, i.e. from a narrow 91.60 (2)° for S1—Ag—S1i, being subtended by the bridging S1 atoms, to a wide 127.43 (2)° for S2—Ag—S3; symmetry operation (i): 1 − x, 1 − y, 1 − z. The Ag2S2 core has the shape of a distorted rhombus as the Ag—S1 bond length of 2.5596 (7) Å is significantly shorter than the Ag—S1i bond of 2.8188 (7) Å. The Ag—S bond lengths fall in two distinct classes, with the Ag—S1b and Ag—St  bond lengths being similar and shorter than Ag—S1ib b Table 1. Despite2S2 core, with the dihedral angles between the core and the N1- and N4-rings being 88.99 (11) and 85.16 (11)°, respectively. The independent rings are close to being co-planar, exhibiting a dihedral angle of 8.38 (16)°. Finally, the N1-amine is orientated to be in close proximity to the S3-thiocyanato atom, enabling the formation of an intramolecular amine-N—H⋯S(thiocyanato) hydrogen bond (Table 2The five-membered rings lie prime to either side of the Agd Table 2. While tii = 3.4444 (15) Å and angle of inclination = 6.81 (16)° for (ii) x, y, z].The crystal of (I)et al., 2004et al., 2019Crystal Explorer 17  of the Hirshfeld surface plotted over dnorm for (I)i.e. S⋯S contacts, are noted. The closest of these, i.e. S1⋯S1iii = 3.2463 (9) Å , link the binuclear molecules into chains along the a-axis direction. On the Hirshfeld surface mapped over electrostatic potential (DFT 3-21G) shown in Fig. 4b), the faint-red and light-blue regions correspond to negative and positive electrostatic potential, respectively,As seen in Fig. 4a)–(f), respectively. The N⋯H/H⋯N contacts, at 35.8%, are the major contributor to the Hirshfeld surface. The S⋯H/H⋯S contacts (19.4%) also make a significant contribution. Other significant contributions come from the C⋯H/H⋯C (12.7%) and S⋯S (8.3%) contacts with H⋯H contacts, occurring at distances beyond the sum of the van der Waals radii, contributing only 7.6%. The next most significant contribution is made by N⋯C/C⋯N contacts (6.7%) arising in the main from the π–π stacking interactions between triazolyl rings.The full and delineated  two-dimensional fingerprint plots are shown in Fig. 5et al., 2017et al., 2017i.e. electrostatic (Eele), polarization (Epol), dispersion (Edis) and exchange–repulsion (Erep); these were obtained using the wave function calculated at the HF/3-21G level of theory. The results are summarized in Table 3−1, having a major electrostatic contribution (−142.4 kJ mol−1), and is associated with the following interatomic contacts: C2—H2⋯N7, C4—H4⋯N7 and π–π stacking of between triazole rings. The next most significant contribution, with a total energy of −125.0 kJ mol−1, arises from conventional hydrogen bonds, i.e. N1—H1N⋯N5, N4—H4N⋯N2 and N6—H6N⋯N7 as well as C2—H2⋯S3 interactions. The next attractive interaction, with Etot = −48.9 and Edis = −120.3 kJ mol−1, respectively, reflects the N3—H3N⋯S2 hydrogen bonding and S1⋯S1 secondary bonding contact.The energy frameworks were simulated –(c), respectively, by energy framework diagrams whereby the cylinders join the centroids of molecular pairs using a red, green and blue colour scheme; the radius of the cylinder is proportional to the magnitude of interaction energy.The magnitudes of intermolecular energies, NWChem package supporting information and their energies were calculated to be 3.011 and 6.173 eV, respectively. The HOMO is delocalized across the thiocyanato groups and the bridging region between the two dimers. The LUMO includes the delocalization around the triazole rings.The HOMO and LUMO energies for the atom positions in the crystal structure of (I)et al., 2016via the thione-S atom, as in (I)3P)2Cu(HtrzSH)Cl]·CH3CN, ]·CH3OH ]·H2O 2(HtrzS)(HtrzSH)·0.5H2O 2(HtrzSH)2]·2H2O}n 2Cl2]n Cl]n (HtrzSH)·0.5H2O 3Sn(HtrzS) (NO3)OH2]n 2(SO4)]n H-1,2,4-triazole-3-thiol  in distilled water (5 ml) was added followed by heating for 4.3 h during which time the precipitate slowly dissolved. The clear solution was filtered and kept to evaporate at ambient temperature. After a few days, colourless trapezoidal prisms of (I)in vacuo. M.p.: 413–417 K. IR : 2108 (s) (C≡N), 1479 (s) (C=N), 1248 (w) (C–N), 1054 (m) (C—S) + (C—N).Silver nitrate  and potassium thiocyanate  were dissolved in acetronitrile (25 ml) and a white precipitate formed. This mixture was heated at 323–325 K for 30 min. Then, a clear solution of 1Uiso(H) = 1.2Ueq. The maximum and minimum residual electron density peaks of 0.96 and 1.04 e Å−3, respectively, were located 0.83 and 0.77 Å from the N3 and Ag atoms, respectively.Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S2056989019016359/hb7868sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019016359/hb7868Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019016359/hb7868sup3.tifFig. S1 Image of the calculated HOMO and LUMO's for (I). DOI: 1969873CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, two supramolecular tapes, each sustained by amide-N—H⋯O(carbonyl) hydrogen bonds and ten-membered {⋯HNC 14H14N4O2·H2O, features a central C2N2O2 residue (r.m.s. deviation = 0.0205 Å) linked at each end to 3-pyridyl rings through methylene groups. The pyridyl rings lie to the same side of the plane, i.e. have a syn-periplanar relationship, and form dihedral angles of 59.71 (6) and 68.42 (6)° with the central plane. An almost orthogonal relationship between the pyridyl rings is indicated by the dihedral angle between them [87.86 (5)°]. Owing to an anti disposition between the carbonyl-O atoms in the core, two intramolecular amide-N—H⋯O(carbonyl) hydrogen bonds are formed, each closing an S(5) loop. Supramolecular tapes are formed in the crystal via amide-N—H⋯O(carbonyl) hydrogen bonds and ten-membered {⋯HNC2O}2 synthons. Two symmetry-related tapes are linked by a helical chain of hydrogen-bonded water molecules via water-O—H⋯N(pyridyl) hydrogen bonds. The resulting aggregate is parallel to the b-axis direction. Links between these, via methylene-C—H⋯O(water) and methylene-C—H⋯π(pyridyl) interactions, give rise to a layer parallel to (10The molecular structure of the title bis-pyridyl substituted diamide hydrate, C In the same way, complexation to metals may also be envisaged. It is therefore not surprising that there is now a wealth of structural information for these molecules occurring in co-crystals, salts and metal complexes, as has been reviewed recently Having both amide and pyridyl functionality, bis Å for N3 and 0.0321 (11) Å for C8. The N1- and N3-pyridyl rings form dihedral angles of 59.71 (6) and 68.42 (6)°, respectively, with the central plane and lie to the same side of the plane, having a syn-periplanar relationship. The dihedral angle formed between the pyridyl rings is 87.86 (5)°, indicating an almost edge-to-face relationship. The carbonyl-O atoms have an anti disposition enabling the formation of intramolecular amide-N—H⋯O(carbonyl) hydrogen bonds that close S(5) loops, Table 1The molecular structures of the two constituents comprising the crystallographic asymmetric unit of (I)via amide-N—H⋯O(carbonyl) hydrogen bonds leading to a sequence of inter-connected ten-membered {⋯HNC2O}2 synthons. Two such tapes are connected by hydrogen bonds provided by the water molecule of crystallization. Thus, alternating water molecules in helical chains of hydrogen-bonded water molecules, being aligned along the b-axis direction and propagated by 21 symmetry, connect to 3LH2via water-O—H⋯N(pyridyl) hydrogen bonds to form the one-dimensional aggregate shown in Fig. 2a). The presence of methylene-C—H⋯O(water) and methylene-C—H⋯π(pyridyl) contacts stabilizes a layer lying parallel to (10b).Significant conventional hydrogen bonding is noted in the crystal of (I)Crystal Explorer 17 dnorm mapping are electrostatic in nature as can be seen from the distinctive blue (electropositive) and red (electronegative) regions on the surface, albeit with varying intensity, Fig. 4a) and (b). This indicates no charge complementarity consistent with the interaction beings mainly dispersive in nature.To verify the nature of the aforementioned interactions, the a), the overall fingerprint plot of (I)3LH2, with splitting of the spike in the internal region due to the formation of the O—H⋯N hydrogen bond, Fig. 5e), suggesting a prominent role played by the water molecule in influencing the overall contacts in (I)4LH2 in which the overall surface contacts for 4LH2 are not very much influenced by the benzene molecule as demonstrated by the similar profiles for the solvate and individual 4LH2 molecule , i.e. H⋯H ∼2.26 Å [Σ(vdW) = 2.40 Å], O⋯H/H⋯O ∼1.88 Å [Σ(vdW) = 2.72 Å], C⋯H/H⋯C ∼2.62 Å [Σ(vdW) = 2.90 Å] and N⋯H/H⋯N ∼2.50 Å [Σ(vdW) = 2.75 Å].The quantification of the close contacts to the Hirshfeld surface was performed through the analysis of the two-dimensional fingerprint plots for (I)3LH2 molecule, the dominance of these contacts follows the order H⋯H , C⋯H/H⋯C , O⋯H/H⋯O  and N⋯H/H⋯N . While the aforementioned interactions are almost evenly distributed between the internal and external contacts for (I)3LH2 are found to either to be inclined towards the internal or external contact region compared with (I)versus -H⋯O- (9.5%) and -N⋯H- (8.8%) versus -H⋯N- (4.6%), respectively, Fig. 5c)–(e).As for the individual di + de 2.26 Å), O⋯H/H⋯O  and H⋯N . In particular, the second most dominant contacts are found to be heavily inclined toward -O⋯H- (30.5%) as compared to -H⋯O- (8.9%), presumably due to relatively large contact surface area.The hydrate molecule exhibits a completely different fingerprint profile, which is dominated by three major contacts, namely H⋯H 2 dimer connected by a ten-membered {⋯HNC2O}2 synthon has the greatest Eint energy of −73.0 kJ mol−1 which is comparable in energy to the classical eight-membered {⋯HOCO}2 synthon , O1W—H1W⋯N1 (−28.6 kJ mol−1), O1W—H2W⋯O1W (−26.2 kJ mol−1), C7⋯O1 (−20.7 kJ mol−1), C5—H5⋯N4 (−13.0 kJ mol−1) and C1—H1⋯O1W (−10.5 kJ mol−1) interactions. As expected, the N2—H2N⋯O1, N3—H3N⋯O2, O1W—H1W⋯N1 and O1W—H2W⋯O1W interactions are associated with distinct electropositive and electronegative sites and therefore, are mainly governed by electrostatic forces, while the rest of the close contacts are dispersive in nature. The relatively stable nature of the C12—H12⋯C7 and C6—H6A⋯O2 interactions as compared to the O1W—H1W⋯N1 and O1W—H2W⋯O1W interactions could be due to the presence of low repulsion energies in the former as compared to the latter.All associations between molecules in (I)N⋯O1/ N3—H3N⋯O2, O1W—H1W⋯N1 and O1W—H2W⋯O1W hydrogen bonding leading to a barricade-like electrostatic energy framework parallel to (a). This is further stabilized by the dispersion forces arising from other supporting interactions which result in another barricade-like dispersion energy framework parallel to (100), Fig. 6b). The overall energy framework for (I)c).The crystal of (I)3LH2 molecule in (I)i.e. Form I and Form II A comparison of the distribution of contacts on the Hirshfeld surfaces between the 3LH2 molecule in (I)Mercury This conclusion is consistent with the analysis of the packing similarity in which a comparison of (I)3LH2 molecule has been characterized in two polymorphs C(=O)N(H)CH2CO2H   to 84.61 (9)°. The comparable range for the S-shaped molecules, for which both dihedral angles are identical from symmetry, is 64.2 (3) to 84.79 (18)°.The N,N′-bis(pyridin-3-ylmethyl)oxalamide, was prepared according to the literature : 3578 ν(O—H), 3321 ν(N—H), 3141–2804 ν(C—H), 1687–1649 ν(C=O), 1524–1482 ν(C=C), 1426 ν(C—N), 710 ν(C=C).The precursor, Uiso(H) set to 1.2–1.5Ueq(C). The oxygen- and nitrogen-bound H atoms were located in a difference-Fourier map and refined with O—H = 0.84±0.01 Å and N—H = 0.88±0.01 Å, respectively, and with Uiso(H) set to 1.5Ueq(O) or 1.2Ueq(N). Owing to poor agreement, one reflection, i.e. (551), was omitted from the final cycles of refinement.Crystal data, data collection and structure refinement details are summarized in Table 610.1107/S2056989019016153/hb7869sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989019016153/hb7869Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989019016153/hb7869Isup3.cmlSupporting information file. DOI: 1969282CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


CO2 can be eliminated by renal replacement therapy but studies are scarce and clinical relevance is unknown. We prospectively studied CO2 and O2 behavior at different sample points of continuous veno-venous hemofiltration (CVVH) and build a model to calculate CO2 removal bedside.Carbon dioxide (CO2 (tCO2), CO2 flow (V̇CO2) and O2 flow (V̇O2) were compared between different sample points. The effect of citrate on transmembrane tCO2 was evaluated. Wilcoxon matched-pairs signed rank test was performed to evaluate significance of difference between 2 data sets. Friedman test was used when more data sets were compared.In 10 patients receiving standard CVVH under citrate anticoagulation, blood gas analysis was performed at different sample points within the CVVH circuit. Citrate was then replaced by NaCl 0.9% and sampling was repeated. Total CO2 in the effluent (26.0 ml/min) correlated significantly with transmembrane V̇CO2 (24.2 ml/min). This represents 14% of the average expired V̇CO2 in ventilated patients. Only 1.3 ml/min CO2 was removed in the de-aeration chamber, suggesting that CO2 was almost entirely cleared across the membrane filter. tCO2 values in effluent, before, and after the filter were not statistically different. Transmembrane tCO2 under citrate or NaCl 0.9% predilution also did not differ significantly. No changes in V̇O2 were observed throughout the CVVH circuit. Based on recorded data, formulas were constructed that allow bedside evaluation of CVVH-attributable CO2 removal.V̇CO2 is removed by CVVH and can be quantified by one simple blood gas analysis within the circuit. Future studies should assess the clinical impact of this observation.A relevant amount of COhttps://clinicaltrials.gov with trial registration number NCT03314363 on October 192,017.The trial was registered at The online version of this article (10.1186/s12882-019-1378-y) contains supplementary material, which is available to authorized users. Subsequently, citrate predilution was stopped and replaced for at least 20 min by NaCl 0.9% at similar flow. Blood gas analysis was repeated according to the same protocol.Inclusion and exclusion criteria are listed in Additional file 2 content (tO2) was calculated as Hb x Hb saturation × 1.35 . V̇CO2 dropped significantly between SP2 and SP3 [from 110.5 ± 9.6 ml/min to 84.5 ± 6.5 ml/min (p < 0.01)]. V̇CO2 at SP4 (26.0 ± 5.8 ml/min) and transmembrane V̇CO2 at SP4 (24.2 ± 2.6 ml/min) were not statistically different (p = 0.39).V̇CO2 (SP1) than V̇CO2 (SP5) [109.8 ± 7.1 ml/min vs. 81.7 ± 5.8 ml/min (p < 0.01)] and a 1.3 ml/min difference between V̇CO2 (SP3) and V̇CO2 (SP5) [83.0 ± 4.9 ml/min vs. 81.7 ± 5.8 ml/min (p = 0.01)].Results for NaCl 0.9% postdilution were plotted in Fig. 2 at SP5 (116.1 ± 9.7 ml/min) and “expected V̇CO2 at SP5” (94.4 ± 9.9 ml/min) , SP3 (25.0 ± 2.6 mmol/l) and SP4 (25.1 ± 2.6 mmol/l) were not statistically different (p = 0.51). tCO2 decreased significantly between SP1 and SP2 from 30.6 ± 2.3 mmol/l to 25.5 ± 2.8 mmol/l (p < 0.01). At all SP, tCO2 consisted of CO2 in gas form (pCO2) and HCO3-   Fig. .Fig. 6Ef2 at SP1, SP2, SP3 and SP5 was respectively 10.6 ± 3.7 ml/min,10.9 ± 3.9 ml/min, 10.3 ± 3.8 ml/min, and 10.9 ± 3.7 ml/min. V̇O2 at SP4 was 0 ml/min as effluent contains no Hb. V̇O2 (SP1) and V̇O2 (SP5) were not different (p = 0.33)  was statistically different, probably because the set CVVH fluid flow at these SP did not correspond with real fluid flow . By adding predilution fluid, tCO2 decreased between SP1 and SP2.As suggested by in vitro hemodialysis, COas HCO3- . The CO22 extraction. Only the short term effect of citrate upon CO2 removal was evaluated as an influencer of acid-base homeostasis. Over a longer time period, citrate could possibly affect CO2 clearance because it preserves membrane porosity better than heparin. tCO2 in blood passing through the CVVH circuit decreased as it was diluted by bicarbonate-free solutions. CVVH had no impact on V̇O2 because values remained constant at the different SP.Citrate anticoagulation did not influence tCO2 removal by CVVH in a clinical setting with the use of only one blood gas analysis in the extracorporeal circuit at a preexisting sample point. As these are the first data that were acquired in a CVVH setting, formulas could not be compared to data from other articles [Based on previous findings, different formulas were constructed to calculate COarticles . Further2 influences expired CO2.Several limitations of our study must be emphasized. First, despite the high number of analyses per patient, the sample size remains small and future studies in more patients are needed to confirm our results. Second, assumptions were made based on “snapshot” blood gas analysis. Continuous monitoring would be more precise. Third, fluid flows as set on CVVH may not correlate with real flow . In-circ2, both as gas and bicarbonate and measurable in the effluent, is removed during CVVH under citrate anticoagulation. Pre-filter tCO2 is the major determinant for CO2 removal. Citrate does not influence CO2 elimination. To a certain extent, bicarbonate fluids influence blood gases but data are too limited to permit relevant conclusions. Oxygen flow is not influenced by CVVH. CO2 removal by CVVH in bicarbonate-free conditions can be calculated by multiplying effluent or blood flow with CO2 content at a preexisting sample point. Their clinical relevance requires confirmation.A significant amount of COAdditional file 1:Inclusion and exclusion criteria that were used during the study. (DOCX 15 kb)Additional file 2:CVVH settings and postdilution fluid per patients. (DOCX 14 kb)