The natural convection boundary layer flow of a viscous incompressible fluid with temperature dependent viscosity and thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface has been investigated. The governing non dimensional form of equations is solved numerically by using finite difference scheme. The numerical results of velocity profile, temperature distribution and mass concentration as well as for skin friction, heat transfer rate and mass transfer rate are presented graphically and in tabular form for various values of dimensionless parameters those are generated in flow model during dimensionalization. From the obtained results, it is concluded that the exothermic catalytic chemical reactions is associated with temperature dependent viscosity and thermal conductivity. Further, it is concluded that the body shape parameter also plays an important quantitative role for change in velocity profile, temperature field and mass concentration behavior in the presence of exothermic catalytic chemical reaction. Merkin and Chaudhary .At this time, please address the following queries:Please clarify the sources of funding  for your study. List the grants or organizations that supported your study, including funding received from your institution.State what role the funders took in the study. If the funders had no role in your study, please state: “The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”If any authors received a salary from any of your funders, please state which authors and which funders.If you did not receive any funding for this study, please state: “The authors received no specific funding for this work.”Please include your amended statements within your cover letter; we will change the online submission form on your behalf.Reviewers' comments:5. Review Comments to the AuthorReviewer #1: The report presents the natural convection boundary layer flow of a viscous incompressible fluid with temperature-dependent viscosity and temperature-dependent thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface. I recommend major revision due to the following facts.1. In Eq. (3), the authors added (u^2/2x)n to the convective acceleration term.Comment: What does the new term means? How did you derive it?2. After Eq. (6), it was written that n = P(x) + Q(x). Whereas  is the wall temperature function and the  is the body shape function.Comment: The authors refer Readers to check "Pop, I. and Takhar, H. S. Free convection from a curved surface. Journal of Applied Mathematicsand Mechanics, 73 (1993), pp. 534 -539" for details.Comment: This is not acceptable. Update the research methodology with the derivation of such momentum equation.3. Research question is needed to harmonize the contribution of the report to the body of knowledge.Comment: Research questions are needed at the end of the introduction section. Research questions are needed. Note that the results in this report are typical answers to unknown questions. This is true because the manuscript provides some powerful answers to unknown questions. Note that the research questions must connect the title to the analysis of results, and conclusion. This would guide authors not to generate many results that are not consistent to provide insight. The author should update the manuscript with appropriate and relevant research questions at the end of the introduction section. This would guide the author to structure logical analysis of results. Logical questions are expected. This would help readers to link what is known in the literature with the novelty of this study.4. The similarity variables presented as Eq. (7) are dimensional. The unit of the first, u, is m^0.5 while that of v is m^{-1/4}, and that of y is also dimensional. Hence, the variables used to non-dimenzionalize the governing equation are not appropriate.Reviewer #2: Recommendation: Minor revisionAuthors should revise the manuscript according to the following comments.• Nomenclature is must.• Some grammatical and typo mistakes are found in the manuscript.• The governing differential equations describing the flow are non-linear. Is the solution obtained unique?• Specify the applications of considered physical model or geometry.• Introduction section should be made more concise to show previous work in the field. At present a lot of related researches are stated in the introduction. However, not sufficient analysis is presented. The authors should ask themselves: what are the problems with the presented researches? Why is the recent work needed? Hope these can improve the present work by following past articles.• Effect of Joule heating on MHD non‐Newtonian fluid flow past an exponentially stretching curved surface• Magnetohydrodynamic Cattaneo-Christov flow past a cone and a wedge with variable heat source/sink• Heat and mass transfer in MHD Casson nanofluid flow past a stretching sheet with thermophoresis and Brownian motion• Effect of asymmetrical heat rise/fall on the film flow of magnetohydrodynamic hybrid ferrofluid• Simultaneous solutions for first order and second order slips on micropolar fluid flow across a convective surface in the presence of Lorentz force and variable heat source/sink• Effect of thermal radiation on MHD Casson fluid flow over an exponentially stretching curved sheet• Influence of non-uniform heat source/sink on the three-dimensional magnetohydrodynamic Carreau fluid flow past a stretching surface with modified Fourier’s law• MHD Carreau Fluid Flow Past a Melting Surface with Cattaneo-Christov Heat Flux• Physical aspects on unsteady MHD‐free convective stagnation point flow of micropolar fluid over a stretching surface• Influence of viscous dissipation on MHD flow of micropolar fluid over a slendering stretching surface with modified heat flux model• A non‐Fourier heat flux model for magnetohydrodynamic micropolar liquid flow across a coagulated sheetNote: I want to see the revised version of the manuscript.https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool,  13 Apr 2021Response to Reviewers Comments (PONE-D-21-04681)Effects of Temperature Dependent Viscosity and Thermal Conductivity on Natural Convection Flow along a Curved Surface in the Presence of Exothermic Catalytic Chemical ReactionReviewer #1: The report presents the natural convection boundary layer flow of a viscous incompressible fluid with temperature-dependent viscosity and temperature-dependent thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface. I recommend major revision due to the following facts.In Eq. (3), the authors added (u^2/2x)n to the convective acceleration term.Comment: What does the new term means? How did you derive it.Response: During dimensionalization of the momentum equation we have equation of the form u ∂u/∂x+v ∂u/∂y+u^2/2 1/g_x (dg_x)/dx=γ_μ (∂θ/∂y)(∂u/∂y) +(1+γ_μ θ)((∂^2 u)/(∂y^2 ))+θ+ϕ,Here, as 1/x ® (P(x ®)+Q(x ®))=1/g_x (dg_x)/(dx ® )and P(x ® )+Q(x ® )=n and thus 1/x ® (n)=1/g_x (dg_x)/(dx ® )u ∂u/∂x+v ∂u/∂y+u^2/2x n=γ_μ (∂θ/∂y)(∂u/∂y) +(1+γ_μ θ)((∂^2 u)/(∂y^2 ))+θ+ϕ, 2. After Eq. (6), it was written that n = P(x) + Q(x). Whereas  is the wall temperature function and the  is the body shape function.Comment: The authors refer Readers to check "Pop, I. and Takhar, H. S. Free convection from a curved surface. Journal of Applied Mathematics and Mechanics, 73 (1993), pp. 534 -539" for details.Comment: This is not acceptable. Update the research methodology with the derivation of such momentum equation.Response: The detail derivation of n=P(x)+Q(x) is given in below steps:Since we know that d/dx (lnx)=1/xand d(lnx)=1/x dxwhich implies that 1/(d(lnx))=x/dx. (1) Also consider d/dx (ln g_x )=1/g_x (dg_x)/dxwhich implies d(ln g_x )=1/g_x dg_x. (2) Now combining the above two equations (1) and (2), we have (d lng_x)/(d lnx)=x/g_x (dg_x)/dx.Now using the non-dimensionless variables, we may write the above equations as(d lng_x)/(d lnx ®l)=(x ®l)/g_x (dg_x)/(dx ®l)which implies that(d lng_x)/(d lnx ®l)=x ®/g_x (dg_x)/(dx ® )and thus we have 1/x ® (d lng_x)/(d lnx ®l)=1/g_x (dg_x)/(dx ® ) (3)Also, we consider d/dx (lnT_w )=1/T_w (dT_w)/dx=0which implies that d lnT_w=0and thus, we can write (d lnT_w)/(d lnx ®l)=0 (4)Now from equation (3) and (4), we have 1/x ® ((d lnT_w)/(d lnx ® l)+(d lng_x)/(d lnx ® l))=1/g_x (dg_x)/(dx ® )which can also be written as 1/x ® (P(x ®)+Q(x ®))=1/g_x (dg_x)/(dx ® ) (5)Here, P(x ®), the wall temperature function and Q(x ®) the body shape function, are defined as P(x ® )=(d lnT_w)/(d lnx ® l), Q(x ® )=(d lng_x)/(d lnx ® l) . (6) 3. Research question is needed to harmonize the contribution of the report to the body of knowledge.Comment: Research questions are needed at the end of the introduction section. Research questions are needed. Note that the results in this report are typical answers to unknown questions. This is true because the manuscript provides some powerful answers to unknown questions. Note that the research questions must connect the title to the analysis of results, and conclusion. This would guide authors not to generate many results that are not consistent to provide insight. The author should update the manuscript with appropriate and relevant research questions at the end of the introduction section. This would guide the author to structure logical analysis of results. Logical questions are expected. This would help readers to link what is known in the literature with the novelty of this study.Response: The overall objectives of this research are to develop the mathematical model to study and compare the different modes of coupling the exothermic and catalytic chemical reaction via momentum, energy and mass concentration equation. Model predictions are used to assess the effects of different parameters on conversion of exothermic catalytic chemical reaction at heated curve generated by tangential component of acceleration due to gravity. The proposed model is used as the guidelines for the selection of a suitable coupling to achieve the desired applications. A numerical technique Finite Difference Method in conjunction with primitive variable formulation is used to investigate the coupling of exothermic reaction with catalyst particles. Furthermore, parametric effects of heated wall and mass concentration along the curved surface are studied and highlighted graphically and as well as in tabular form. 4. The similarity variables presented as Eq. (7) are dimensional. The unit of the first, u, is m^0.5 while that of v is m^{-1/4}, and that of y is also dimensional. Hence, the variables used to non-dimenzionalize the governing equation are not appropriate.Response: In the section of numerical analysis, we have used primitive variable formulation given as below: u=x^(1⁄2) U,v=x^((-1)⁄4) V, x=X,y=x^(1⁄4) Y,  θ=Θ(X.Y), C=Φ.  It is pertinent to mention that primitive variable are dimensionless, we use this transformation to get primitive form of partial differential equations, please see red terms in each equation  After using the aforementioned transformations, we have the following form of system of equations:U/2+X ∂U/∂X-Y/4 ∂U/∂Y+∂V/∂Y=0,[1/2+n/2] U^2+XU ∂U/∂X+(V-YU/4) ∂U/∂Y=γ_μ ∂Θ/∂Y ∂U/∂Y+(1+γ_μ Θ) (∂^2 U)/(∂Y^2 )+Θ+Φ,XU ∂Θ/∂X+(V-YU/4) ∂Θ/∂Y=1/Pr [ξ(∂Θ/∂Y)^2+(1+ξΘ) (∂^2 Θ)/(∂Y^2 )]+βλ^2 X^(1⁄2) (1+nγΘ)exp((-E)/(1+γθ))Θ,XU ∂Φ/∂X+(V-YU/4) ∂Φ/∂Y=1/Sc (∂^2 Φ)/(∂Y^2 )+λ^2 X^(1⁄2) (1+nγΘ)exp((-E)/(1+γθ))Φ.Reviewer #2: Recommendation: Minor revisionAuthors should revise the manuscript according to the following comments.• Nomenclature is must.Response: The nomenclature has been included in the revised manuscript.• Some grammatical and typo mistakes are found in the manuscript.Response: In the revised manuscript we have correct the grammatical issues.• The governing differential equations describing the flow are non-linear. Is the solution obtained unique?Response: Please if you focus on the graphs and boundary conditionsU_=0, V_=0,Θ_ =1, Φ_=1 at Y_j=0 U_→0, 〖 θ〗_→0, Φ_(i.j)→0 as Y_j→∞ In these graphs and all other graphs given in this study, the solutions are satisfying by the boundary conditions, it is evident of the correctness of the obtained results. • Specify the applications of considered physical model or geometry.Response: The proposed model is used as the guidelines for the selection of a suitable coupling to achieve the desired applications. The curved shaped geometry is used to design many problems of civil engineering as pressure barrier.• Introduction section should be made more concise to show previous work in the field. At present a lot of related researches are stated in the introduction. However, not sufficient analysis is presented. The authors should ask themselves: what are the problems with the presented researches? Why is the recent work needed? Hope these can improve the present work by following past articles.• Effect of Joule heating on MHD non‐Newtonian fluid flow past an exponentially stretching curved surface• Magneto hydrodynamic Cattaneo-Christov flow past a cone and a wedge with variable heat source/sink• Heat and mass transfer in MHD Casson nanofluid flow past a stretching sheet with thermophoresis and Brownian motion.• Effect of asymmetrical heat rise/fall on the film flow of magneto hydrodynamic hybrid Ferro fluid• Simultaneous solutions for first order and second order slips on micro polar fluid flow across a convective surface in the presence of Lorentz force and variable heat source/sink.• Effect of thermal radiation on MHD Casson fluid flow over an exponentially stretching curved sheet• Influence of non-uniform heat source/sink on the three-dimensional magneto hydrodynamic Carreau fluid flow past a stretching surface with modified Fourier’s law• MHD Carreau Fluid Flow Past a Melting Surface with Cattaneo-Christov Heat Flux• Physical aspects on unsteady MHD‐free convective stagnation point flow of micro polar fluid over a stretching surface• Influence of viscous dissipation on MHD flow of micro polar fluid over a slandering stretching surface with modified heat flux model• A non‐Fourier heat flux model for magneto hydrodynamics micro polar liquid flow across a coagulated sheetNote: I want to see the revised version of the manuscript.Response: Most relevant papers are added to enrich introduction (see in introduction ref [23] - [30]) in the revised manuscript.AttachmentResponse to Reviewers Comments.docxSubmitted filename: Click here for additional data file. 28 Apr 2021PONE-D-21-04681R1Effects of Temperature Dependent Viscosity and Thermal Conductivity on Natural Convection Flow along a Curved Surface in the Presence of Exothermic Catalytic Chemical ReactionPLOS ONEDear Dr. Ali,Thank you for submitting your manuscript to PLOS ONE. 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Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: We look forward to receiving your revised manuscript.Kind regards,Naramgari Sandeep, Ph.DAcademic EditorPLOS ONEJournal Requirements:Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.Reviewers' comments:Reviewer's Responses to Questions6. Review Comments to the AuthorPlease use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. Reviewer #1: The report presents the natural convection boundary layer flow of a viscous incompressible fluid with temperature-dependent viscosity and temperature-dependent thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface. I recommend minor revision due to the following facts.Q1. In Eq. (3), the authors added (u^2/2x)n to the convective acceleration term.Comment: What does the new term means? How did you derive it.In the report, the derivation presented by the Authors is in isolation. You are expected to derive it as a convective acceleration of momentum equation.Q2. After Eq. (6), it was written that n = P(x) + Q(x). Whereas  is the wall temperature function andthe  is the body shape function.This is the exact contribution of the report to the body of knowledge and it should be introduced under the introduction section. In fact, a paragraph is needed to announce this novelty.Q3. How do you study a fluid flow along a vertical surface without buoyancy forces? This is true because there is nothing like the associated dimensionless parameter called buoyancy parameter or Grashof number.Q4. Before Eq. 7, was defined as the tangential component of acceleration due to gravity. What is r in the definition?Reviewer #2: The revisions are Good but some references are not arranged properly. Hence I recommend for possible publication.https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool,  14 May 2021Reply to Review PONE-D-21-04681R1Effects of Temperature Dependent Viscosity and Thermal Conductivity on Natural Convection Flow along a Curved Surface in the Presence of Exothermic Catalytic Chemical Reaction PLOS ONEReviewer #1: The report presents the natural convection boundary layer flow of a viscous incompressible fluid with temperature-dependent viscosity and temperature-dependent thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface. I recommend minor revision due to the following facts.Q1. In Eq. (3), the authors added (u^2/2x)n to the convective acceleration term.Comment: What does the new term means? How did you derive it. In the report, the derivation presented by the Authors is in isolation. You are expected to derive it as a convective acceleration of momentum equation.Response: The detail derivation of momentum equation is given as below:The dimensioned form of momentum equation in article is given as underu ∂u/∂x+v ∂u/∂y=1/ρ ∂/∂y (μ ∂u/∂y)+g_x β_T (T-T_∞ )+g_x β_C (C-C_∞) (1)Dimensionless variables x ®=x/l,y ®=y/l Gr^(1/4),u ®=u/U_s ,v ®=v/V_s Gr^(1/4),θ=(T-T_∞)/(T_w-T_∞ ) ,ϕ =(C-C_∞)/(C_w-C_∞ ) (2)To convert the equation (1) into dimensionless form we use the dimensionless variables defined in equation (2), for this we find the term s one by one appeared in the equation (1)u ∂u/∂x=U_s u ® (∂U_s u ®)/(∂x ®l)=(U_s^2)/l u ® (∂u ®)/(∂x ® )+〖U_s u ®〗^2/l (∂U_s)/(∂x ® )u ∂u/∂x=(U_s^2)/l u ® (∂u ®)/(∂x ® )+〖U_s u ®〗^2/l ∂/(∂x ® ) (g_x β_T ΔT)^(1/2)u ∂u/∂x=(U_s^2)/l u ® (∂u ®)/(∂x ® )+〖U_s u ®〗^2/l (g_x β_T ΔT)^(1/2) 1/(2√(g_x )) (dg_x)/(dx ® ) u ∂u/∂x=(U_s^2)/l [u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )] (3)Nowv ∂u/∂y=U_s v ®Gr^(-1/4) (∂U_s u ®)/(∂ly ®Gr^(-1/4) )=(U_s^2)/l v ® (∂u ®)/(∂y ® ) (4)Now1/ρ ∂/∂y (μ ∂u/∂y)=1/ρ [∂μ/∂y ∂u/∂y+μ (∂^2 u)/(∂y^2 )] (5)Considering ∂μ/∂y=∂/∂y μ_o (1+γ^* (T-T_∞))∂μ/∂y=∂/(∂y ®lGr^(-1/4) ) (μ_o (1+γ^* ΔTθ))∂μ/∂y=(μ_o γ^* ΔT)/(lGr^(-1/4) ) ∂θ/(∂y ® )∂μ/∂y=(μ_o γ_T)/(lGr^(-1/4) ) ∂θ/(∂y ® ) (6)∂u/∂y=(∂U_s u ®)/(∂y ®lGr^(-1/4) )=U_s/(lGr^(-1/4) ) (∂u ®)/(∂y ® ) (7)(∂^2 u)/(∂y^2 )=(∂U_s u ®)/(∂y ®lGr^(-1/4) )=U_s/(lGr^(-1/2) ) (∂^2 u ®)/(∂y ®^2 ) (8)Put eqs. (6)-(8) in eq. (5) we have 1/ρ ∂/∂y (μ ∂u/∂y)=1/ρ [(μ_o γ_μ)/(lGr^(-1/4) ) ∂θ/(∂y ® ) U_s/(lGr^(-1/4) ) (∂u ®)/(∂y ® )+(μU_s)/(lGr^(-1/2) ) (∂^2 u ®)/(∂y ®^2 )]1/ρ ∂/∂y (μ ∂u/∂y)=1/ρ [(μ_o γ_μ U_s)/(l^2 Gr^(-1/2) ) ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+〖μ_o (1+γ_μ θ)U〗_s/(l^2 Gr^(-1/2) ) (∂^2 u ®)/(∂y ®^2 )]1/ρ ∂/∂y (μ ∂u/∂y)=(μ_o U_s)/(ρl^2 Gr^(-1/2) ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]Where γ_(μ=) γ^* ΔT1/ρ ∂/∂y (μ ∂u/∂y)=(μ_o U_s)/(ρl^2 Gr^(-1/2) ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )] (9)Put the eqs. (3-4) and Eq. (9) in eq. (1)(U_s^2)/l [u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )]=(μ_o U_s Gr^(1/2))/(ρl^2 ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]+g_x β_T ΔTθ+g_x β_C ΔCϕ [u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )]=(μ_o Gr^(1/2))/(ρlU_s ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]+(〖lg〗_x β_T ΔTθ)/(U_s^2 )+(〖lg〗_x β_C ΔTϕ)/(U_s^2 ) u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )=(νGr^(1/2))/(lU_s ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]+(〖lg〗_x β_T ΔTθ)/(U_s^2 )+(〖lg〗_x β_C ΔCϕ)/(U_s^2 )u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )=(νGr^(1/2))/(lU_s ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]+(〖lg〗_x β_T ΔTθ)/(U_s^2 )+(〖lg〗_x β_C ΔCϕ)/(U_s^2 )Where U_s=(g_x β_T ΔTl)^(1/2),Gr=(g_x β_T ΔTl^3)/ν^2 and U_sc=(g_x β_T ΔCl)^(1/2),Gr^*=(g_x β_T ΔCl^3)/ν^2 So u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )=(νGr^(1/2))/(lU_s ) [γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )]+(U_s^2 θ)/(U_s^2 )+(U_s^2 ϕ)/(U_s^2 )u ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )=γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )+θ+ϕ (10)Where the detail derivation of n=P(x)+Q(x) is given in below steps:Since we know thatd/dx (lnx)=1/xandd(lnx)=1/x dxwhich implies that1/(d(lnx))=x/dx. Also considerd/dx (ln g_x )=1/g_x (dg_x)/dxwhich impliesd(ln g_x )=1/g_x dg_x. (d lng_x)/(d lnx)=x/g_x (dg_x)/dx.Now using the non-dimensionless variables, we may write the above equations as(d lng_x)/(d lnx ®l)=(x ®l)/g_x (dg_x)/(dx ®l)which implies that(d lng_x)/(d lnx ®l)=x ®/g_x (dg_x)/(dx ® )and thus we have 1/x ® (d lng_x)/(d lnx ®l)=1/g_x (dg_x)/(dx ® ) Also, we consider d/dx (lnT_w )=1/T_w (dT_w)/dx=0which implies that d lnT_w=0and thus, we can write (d lnT_w)/(d lnx ®l)=0 Now from equation (c) and (d), we have1/x ® ((d lnT_w)/(d lnx ® l)+(d lng_x)/(d lnx ® l))=1/g_x (dg_x)/(dx ® )which can also be written as 1/x ® (P(x ®)+Q(x ®))=1/g_x (dg_x)/(dx ® ) Here, P(x ®), the wall temperature function and Q(x ®) the body shape function, are defined asP(x ® )=(d lnT_w)/(d lnx ® l), Q(x ® )=(d lng_x)/(d lnx ® l) . Now (10) becomesu ® (∂u ®)/(∂x ® )+u ®^2/2(P(x ® )+Q(x ®))+v ® (∂u ®)/(∂y ® )=γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )+θ+ϕ (11) Now P(x ® )+Q(x ® )=nThus (11) becomesu ® (∂u ®)/(∂x ® )+u ®^2/2 1/g_x (dg_x)/(dx ® )+v ® (∂u ®)/(∂y ® )=γ_μ ∂θ/(∂y ® ) (∂u ®)/(∂y ® )+(1+γ_μ θ)(∂^2 u ®)/(∂y ®^2 )+θ+ϕ Which is dimensionless form of momentum equation along curved surface, and n is the body shape parameter.Q2. After Eq. (6), it was written that n = P(x) + Q(x). Whereas  is the wall temperature function andthe  is the body shape function. This is the exact contribution of the report to the body of knowledge and it should be introduced under the introduction section. In fact, a paragraph is needed to announce this novelty.Response: In current paper we are investigated the natural convection flow over a two dimensional body of arbitrary geometric configuration in the presence of exothermic catalytic chemical reaction. The momentum, energy, and mass concentration equations are a general form suitable for laminar natural convection flows along curved surface in the inclusion of exothermic catalytic reaction. For body of arbitrary shape, the special case in which P(x ® )+Q(x ® )=n, thus the body shape parameter (index parameter) n has chosen 0<n≤1/2 which is main novelty of this work.Note: This paragraph has inserted in the introduction section.Q3. How do you study a fluid flow along a vertical surface without buoyancy forces? This is true because there is nothing like the associated dimensionless parameter called buoyancy parameter or Grashof number.Response: Please if you see the dimensionless variables used to dimensionalize the flow model Dimensionless variables x ®=x/l,y ®=y/l Gr^(1/4),u ®=u/U_s ,v ®=v/V_s Gr^(1/4),θ=(T-T_∞)/(T_w-T_∞ ) ,ϕ =(C-C_∞)/(C_w-C_∞ )  Here Grashof number is used as y ®=y/l Gr^(1/4), v ®=v/V_s Gr^(1/4) where Gr=(gβ∆Tx^3)/ν^2 , which is infact responsible for buoyancy force and it is used in dimensionalization . Dimensionless temperature variable θ=(T-T_∞)/(T_w-T_∞ ), it is the ratio of temperature difference. The problem under consideration is based on natural convection heat transfer, natural convection occurred because of the difference in density, and difference in density is due to the difference in temperature. The contribution of θ in momentum is obvious and sufficient answer to question.Q4. Before Eq. 7, was defined as the tangential component of acceleration due to gravity. What is r in the definition?Response: Here, x is the boundary layer coordinate along the curved surface while r and z are the horizontal and vertical coordinates of the points of the shape curve z=z(r) respectively. It is pertinent to mention that here flow is along the curved surface and dr/dz=0 means there is no flow inner side of the curve. The coordinate z is the vertical distance measure from the lower stagnation point (Please see fig. 1 flow configuration and coordinate system).Reviewer #2: The revisions are Good but some references are not arranged properly. Hence I recommend for possible publication.Response: We have focused on references, all the references are now in good order and well targeted to the problem under consideration.AttachmentResponse to Reviewers Comments.docxSubmitted filename: Click here for additional data file. 17 May 2021Effects of Temperature Dependent Viscosity and Thermal Conductivity on Natural Convection Flow along a Curved Surface in the Presence of Exothermic Catalytic Chemical ReactionPONE-D-21-04681R2Dear Dr. Ali,We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.Within one week, you’ll receive an e-mail detailing the required amendments. 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For more information, please contact Kind regards,Naramgari Sandeep, Ph.DAcademic EditorPLOS ONEAdditional Editor Comments :The revised version is acceptable for publication.Reviewers' comments: 19 Jul 2021PONE-D-21-04681R2 Effects of Temperature Dependent Viscosity and Thermal Conductivity on Natural Convection Flow along a Curved Surface in the Presence of Exothermic Catalytic Chemical Reaction Dear Dr. Ali:I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. onepress@plos.org.If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact plosone@plos.org. 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The electrophilic activation of B−H bonds in the carborane moiety gives rise to a proton transfer from boron to nitrogen at slightly elevated temperatures, as rationalized by the isolation of a mixture of the zwitterionic isomers 12‐ and 7‐[2‐(tBuN{H}CH)C6H4Te(CB11H11)] in ratios ranging from 62 : 38 to 80 : 20.The aryltellurenyl cation [2‐( B−H bond activation: The Lewis superacidic aryltellurenyl cation [2‐(tBuNCH)C6H4Te]+ increases the Brønsted acidity of the weakly coordinating carborane anion (CB11H12)− by more than 120 orders of magnitude. Upon heating, the formal B−H bond is converted into an acidic N−H bond, while a Te−B bond is formed. A mechanism for the electrophilic substitution is proposed. Main‐group elements mediating bond activation of small molecules and catalytic transformations have attracted considerable attention in recent years.tBuNCH)C6H4Te]+ (I), containing an imino donor functionality can be regarded as an intramolecular regular N→Te Lewis pair, however, the intramolecularly coordinating 2‐tert‐butyl‐iminomethylphenyl group compensates the electron deficiency at the tellurium atom only insufficiently .tBuNCH)C6H4Te][X] 3}4]−) show significant Te⋅⋅⋅O and Te⋅⋅⋅F interactions in the solid state, whereas in nonpolar solvents the electrolytic dissociation remains incomplete. In an effort to obtain an essentially isolated [2‐(tBuNCH)C6H4Te]+ (I) cation, we turned our attention to an alternative WCA, namely, the closo‐carborane anion [CB11H12]−, which is known as robust entity with a very low reactivity.tBuNCH)C6H4TeCl (II)11H12]tBuNCH)C6H4Te][CB11H12] (1), which was isolated as yellow crystals in 99 % yield (Scheme 1 is shorter than that of (tBuNCH)C6H4Te][O3SCF3] (2.113(1) Å), but longer than those of (tBuNCH)C6H4Te][SbF6] (2.076(2) Å) and (tBuNCH)C6H4Te][Al{OC(CF3)3}4] (2.051(4) Å). The cation and anion of 1 are associated by a prominent Te⋅⋅⋅H contact (2.550(1) Å) with the B−H functionality in the B12 position.1 is in fact only metastable and susceptible to further transformations at slightly elevated temperatures, both in CH2Cl2 and the solid state. Gentle heating of 1 in inert solvents produced a mixture of two isomeric dinuclear donor‐acceptor complexes [2‐(tBuNCH)C6H4Te⋅D][CB11H12] C6H4Te]CB11H11 (5 a) and 2 b, D=7‐[2‐(tBuN{H}CH)C6H4Te]CB11H11 (5 b)) in ratio 80 : 20,2 a(2 b) (3.034(1) Å) is substantially longer than that of [MesTe(TeMes2)](O3SCF3) (2.808(1) Å)2)](SbF6) (2.765(1) Å)2 a(2 b) (2.228(1) Å) is substantially longer than in 1. As a result, the corresponding Te→Te vibration mode in Raman spectra of 2 a(2 b) (122 cm−1) is considerably shifted bathochromically in comparison to ([MesTe(TeMes2)](SbF6) (143 cm−1) indicating a rather weak Te−Te bond.2 a(2 b) is virtually insoluble in CH2Cl2 and aromatic solvents, it very easily dissolves in THF via dissociation of the Te→Te bond . Consequently, the formation of 1 equiv. of [2‐(tBuNCH)C6H4Te⋅THF][CB11H12] (3) is observed along with releasing of (1−x) equiv. of 12‐[2‐(tBuN{H}CH)C6H4Te]CB11H11 (5 a) and x equiv. of 7‐[2‐(tBuN{H}CH)C6H4Te]CB11H11 (5 b) from the mixture of 2 a and 2 b in molar ratio (1−x):x (Scheme tBuNCH)C6H4TeCl with Ag[CB11H12] directly afforded the mononuclear donor‐acceptor complexes [2‐(tBuNCH)C6H4Te⋅D][CB11H12] 3 (D=THF) and 4 (D=DMAP) as yellowish crystals in 95 % and 83 % yield  with the following activation parameters: ΔG≠298=118.4 kJ mol−1; ΔH≠=114.9 kJ mol−1; ΔS≠=−11.8 J mol−1 K−1. The most straightforward way providing the quantitative yield of the zwitterionic species 5 a and 5 b (in a ratio of 62 : 38) was heating of complex 3 in the solid state at 140 °C for 2.5 h, which effectively removes the THF (details in the Supporting Information). The formation of 5 a and 5 b (donors D in case of 2 a(2 b)) may be rationalized by hydrogen transfer from the B−H functions in the B12 and B7 positionscloso‐carborane anion [CB11H12]− to the lone pair of the N atom in 1, upon which a Te−B12(B7) bond is formed. This hydrogen transfer is facilitated by the cooperative reactivity of the intramolecular regular N→Te Lewis pair. While the Lewis acidic Te site reverses the formal polarity of the B−H bond from hydridic to protic, the Lewis basic N‐atom serves as a final proton acceptor within its gradual transfer from the Te atom to the N atom . Thus, the Lewis super acid [2‐(tBuNCH)C6H4Te]+ (I) has activated the closo‐carborane ion [CB11H12]−, which serves as a proton donor. In fact, such a bond arrangement gives a unique insight into a long unresolved issue of electrophilic activation of closo‐[CB11H12]− (see below).3) to dark red, but also by a dramatic change in the δ(125Te) valuesII site to neutral in the zwitterionic 5 a(5 b) by the Te−B12(B7) bond formation. Consequently, the boron atom at the B12 position of the free [CB11H12]− anion of 3 resonating in 11B NMR at −7.3 ppm is high‐field shifted upon formation of Te−B12 bond in compound 5 a to −11.5 ppm. While the unsubstituted B12 atom in case of 5 b containing Te−B7 bond resonates slightly more low‐field at −5.8 ppm, the signal of boron atom at the B7 position is shifted to high field from δ(11B)=−13.7 ppm in 3 to δ(11B)=−17.3 ppm. Interestingly, both Te−B12 and Te−B7 atoms in 5 a and 5 b are in 11B NMR significantly low‐field shifted (Δδ ∼7 ppm) in comparison to analogously monoiodo substituted derivatives of closo‐carbadodecaborate.5 a(5 b) features a weak intramolecular hydrogen bond of the type N−H⋅⋅⋅Te (N−H: 0.860(2) Å, H⋅⋅⋅Te (2.568(1) Å, N⋅⋅⋅Te: 3.320(1) Å), in which Te serves as unprecedented hydrogen bond acceptor. This bonding situation is a result of the 5 a(5 b) formation mechanism (see below) enforcing the E configuration of the protonated imino CH=NH+ moiety for both products, which is manifested by observation of typical 3J values (acquired in CD2Cl2) of 17.3 and 17.4 Hz, respectively. Although the intramolecular hydrogen bond of the type N−H⋅⋅⋅Te was found in the solid state, the coupling constant 1J=85.3 Hz for both 5 a and 5 b in the solution spectra lies in range for protonated imines.5 a and 5 b contain such bonding interaction, FTIR is showing no shift of the N−H bond ν vibration in the solid state sample (5 a: 3244 cm−15 b: 3295 cm−1) in comparison to adducts 2 a and 2 b (3244 cm−1 and 3297 cm−1) having no N−H⋅⋅⋅Te interaction. Finally, deprotonation of 5 a(5 b) was achieved upon addition of triethylamine, which afforded a mixture of [Et3NH][12‐{2‐(tBuNCH)C6H4Te}CB11H11] (6 a) and [Et3NH][12‐{2‐(tBuNCH)C6H4Te}CB11H11] (6 b) in the same molar ratio as given by parent compounds 5 a(5 b), which was isolated as orange oil in quantitative yield (Scheme δ(15N)=−172.1 ppm acquired in [D8]THF for 5 a(5 b) is shifted to low field for 6 a and 6 b up to −35.4 and −32.8 ppm, respectively. Despite the assessable lone pair of the N atom in the 6 a(6 b) for coordination of Te atom, we can conclude that in this case no N→Te interaction is present, as δ(15N) for these compounds approaches the value of δ(15N) for the unsubstituted parent Schiff base, namely (tBuNCH)C6H5 .The aryltellurenyl cation, + (I) induces an electrophilic activation of the 12‐ or 7‐B−H bond in the closo‐carborane ion5 a and 5 b. The proton transfer from 1’ to 5 a is associated with an energy gain of 193.3 kJ mol−1 and most likely proceeds via a concerted wagging motion involving the transition state TS with double triangular arrangement of N, Te and B12−H, which accounts for an activation barrier of 118.1 kJ mol−1  as discussed above. The AIM bond topology of TS reveals a curved Te−H(B) bond path, indicating the onset of Te−B bond formation ) of 0.59 eÅ‐3 and considerably negative total energy over ED ratio (H/ρ(r)) of −0.38 a.u., covalent bonding aspects of the Te−H contact in the TS are much higher than in 1 (ρ(r)=0.34, H/ρ(r)=−0.21 a.u.) and 5 a (ρ(r)=0.23, H/ρ(r)=−0.14 a.u.). This is supported by the NCI, which shows a ring‐shaped and red‐colored NCI basin enclosing the Te−H and Te−B bonding axes, in contrast to the disc‐shaped and blue‐colored NCI basins in 1 and 5 . In 5 a, only the N (77 %) and now protic H (23 %) atoms contributions are relevant, supporting a coordinative Te⋅⋅⋅H bonding mode C6H4Te]+ (I), and the weakly coordinating closo‐carborane anion [CB11H12]− give rise to a metastable contact ion pair [2‐(tBuNCH)C6H4Te][CB11H12] (1), in which the B−H bond in the 12‐ or 7‐position of closo‐[CB11H12]− is activated by the proximity of a Lewis superacidic cation, the Brønsted acidity of the closo‐carborane is extremely increased, and this triggers proton transfer and the formation of 12‐[2‐(tBuN{H}CH)C6H4Te]CB11H11 (5 a) and 7‐[2‐(tBuN{H}CH)C6H4Te]CB11H11 (5 b) in ratios ranging from 62 : 38 to 80 : 20.1 can be regarded as a snapshot of the first step of the electrophilic substitution of closo‐[CB11H12]−, which is poorly understood in general.closo‐[CB11H12]−[22] involving the formation of three‐center bonded intermediate [MeBH]+. We are currently investigating the utility of I for the activation of small molecules.In summary, the aryltellurenyl cation [2‐ should be addressed to the authors.Supporting InformationClick here for additional data file.


The dihydroquinoxaline moiety, with the exception of the N atom, is essentially planar with the attached phenyl ring inclined to it by 11.64 (6)° and the inner part of the methylpropanoate group nearly perpendicular to it. In the crystal, inversion dimers formed by C—H⋯O hydrogen bonds are connected into oblique stacks by π-stacking and C—H⋯π(ring) interactions. 18H16N2O3, the dihydroquinoxaline moiety, with the exception of the N atom is essentially planar with the inner part of the methylpropanoate group (CH2—CH2—O) nearly perpendicular to it. In the crystal, inversion dimers formed by C—H⋯O hydrogen bonds are connected into oblique stacks by π-stacking and C—H⋯π(ring) interactions.In the title molecule, C The overall conformation is determined in part by the intramolecular C5—H5⋯O3 and C14—H14⋯O1 hydrogen bonds  Å (r.m.s. deviation of the nine fitted atoms = 0.0116 Å). N1 lies 0.0526 (12) Å below the mean plane. The C9–C14 phenyl ring is inclined to the above plane by 11.64 (6)° while the inner part  Å, dihedral angle = 12.20 (6)°] and in addition C16—H16B⋯O3ii and C18—H18A⋯Cg2iii interactions . The crystal packing also shows a C17=O3⋯Cg2 interaction .In the crystal, inversion dimers are formed by C4—H4⋯O3et al., 2016II yielded 30 hits of which those most similar to the title molecule have the formula III with R = Me and R′ = CH2CO2H   and side (bottom) views of the Hirshfeld surface plotted over dnorm in the range −0.1367 to 1.2965 a.u. One of the intramolecular C—H⋯O hydrogen bonds is indicated by the arrow at the left in the front view while those leading to the formation of the inversion dimers are shown by the arrows on the right of the front view. The C—H⋯π(ring) interaction and the π-stacking interactions are represented by the red spots designated by arrows in the side view. Fig. 3b presents the same two views of the surface plotted over the shape-index. In the front view, the π-stacking interaction is evident at the center as an orange triangle surrounded by blue triangles. Fig. 3c has the same two views of the surface plotted over the curvature index, with the flat area in the center indicating the locus of the π-stacking interaction. Fig. 4a) and those delineated into H⋯H contacts , H⋯O/O⋯H contacts , H⋯C/C⋯H contacts  and C⋯C contacts .An effective means of probing intermolecular interactions is Hirshfeld surface analysis  were added 2-bromoethyl acetate , potassium carbonate  and a catalytic quantity of tetra-n-butylammonium bromide. The reaction mixture was stirred at room temperature for 24 h. The solution was filtered and the solvent removed under reduced pressure. The residue thus obtained was chromatographed on a silica gel column using a hexane/ethyl acetate 9.5: 0.5 mixture as eluent. The solid obtained was recrystallized from ethanol solution to afford colorless column-like specimen of the title compound. Yield: 0.50 g, 67%; m.p. 471–473 K.To a solution of 2-oxo-3-phenyl-1,2-dihydroquinoxaline  in 1H NMR  δ (ppm): 8.24 ; 7.91 ; 7.82 ; 7.53 ; 7.25 ; 4.73 ; 3.92 ; 2.23 .13C NMR  δ (ppm):46.15 (N—CH2); 61.15 (O—CH2); 114.38, 123.82, 127.01, 127.72, 128.13, 128.96, 129.68, 130.33, 130.45,130.62 (CH—Ar); 132.78, 133.36, 135.40, 136.05, 154.24(Cq); 156.92 (C=O); 177.82 (O—C=O).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989021005247/vm2249sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989021005247/vm2249Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021005247/vm2249Isup3.cmlSupporting information file. DOI: 2062956CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Additional N—H⋯O hydrogen bonds link the chains into layers parallel to (100).The title molecule adopts an angular conformation. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds together with C—H⋯π(ring) interactions form chains extending along the  13H16N4O, adopts an angular conformation. In the crystal a layer structure is generated by N—H⋯O and N—H⋯N hydrogen bonds together with C—H⋯π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (53.8%), H⋯C/C⋯H (21.7%), H⋯N/N⋯H (13.6%), and H⋯O/O⋯H (10.8%) interactions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/ 6–311 G level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 5.0452 eV.The title molecule, C Bond diB⋯O1, and N2—H2A⋯N1 hydrogen bonds, together with C11—H11⋯Cg2 interactions . The positive electrostatic potential (blue region) over the surface indicates hydrogen-donor potential, whereas the hydrogen-bond acceptors are represented by negative electrostatic potential (red region). The shape-index . The most important interaction is H⋯H, contributing 53.8% to the overall crystal packing, which is reflected in Fig. 6b as widely scattered points of high density due to the large hydrogen content of the molecule, with the tip at de = di = 1.18 Å. In the presence of C—H interactions, the pair of characteristic wings in the fingerprint plot delineated into H⋯C/C⋯H contacts (21.7% contribution to the HS), Fig. 6c, has the tips at de + di = 2.76 Å. The pair of scattered points of spikes in the fingerprint plot delineated into H⋯N/N⋯H, Fig. 6d (13.6%), have the tips at de + di = 2.01 Å. Finally, the H⋯O/O⋯H contacts, Fig. 6e, make only a 10.8% contribution to the HS and have a low-density distribution of points.The overall two-dimensional fingerprint plot , hardness (η), ionization potential (I), dipole moment (μ), electron affinity (A), electrophilicity (ω) and softness (σ) are collated in Table 3N-(2-amino-5-methylphenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide system. The energy band gap [ΔE = LUMOE − HOMOE] of the molecule is 5.0452 eV, and the frontier molecular orbital energies, HOMOE and LUMOE, are −5.3130 and −0.2678 eV, respectively.The structure in the gas phase of the title compound was optimized by means of density functional theory. The density functional theory calculation was performed by the hybrid B3LYP method and the 6–311 G basis-set, which is based on Becke’s model acetamide fragment yielded multiple matches. Of these, two had an N-(2-aminophenyl) substituent comparable to (I)et al., 2019cN-(2-{[(4-methylphenyl)methylidene]amino}phenyl) on nitrogen 2. The second one (III)  on nitrogen 2. The pyrazole ring (N3/N4/C10–C12) in XITFUE is inclined to the C1–C6 benzene ring by 70.83 (8)°. In YODZEZ, the dihedral angle between the mean planes of the 2-aminophenyl and pyrazolyl rings is 65.63 (8)°. In (I)A search of the Cambridge Structural Database -4-(2-oxopropylidene)-1,5-benzodiazepin-2-one and a stoichiometric amount of hydrazine were refluxed in ethanol (40 mL) for 2 h. After concentration of the solvent volume to 20 mL, the solution was allowed to stand; the precipitate formed was filtered off and then recrystallized in ethanol. Single crystals were obtained after recrystallization from methanol in the presence of MnCl2·4H2O, which was left at room temperature for 72 h. Yield: 70%.2 g (9.3 mmol) of  global, I. DOI: 10.1107/S205698902100503X/dj2025Isup5.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S205698902100503X/dj2025Isup3.cmlSupporting information file. DOI: 2083102CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The layered crystal packing is further consolidated by van der Waals and C—H⋯π interactions.In the crystal, molecules are linked by pairs of N—H⋯O hydrogen bonds into ribbons along the  14H12N4O7·0.224H2O, is nearly planar with a maximum deviation from the least-squares plane of 0.352 (1) Å. The molecular conformation is stabilized by an intramolecular N—H⋯O hydrogen bond, generating an S(6) ring motif. In the crystal, molecules are linked by centrosymmetric pairs of N—H⋯O hydrogen bonds, forming ribbons along the c-axis direction. These ribbons connected by van der Waals contacts, forming sheets parallel to the ac plane. There are also intermolecular van der Waals contacts and and C—H⋯π interactions between the sheets. A Hirshfeld surface analysis indicates that the most prevalent interactions are O⋯H/H⋯O (41.2%), H⋯H (19.2%), C⋯H/H⋯C (12.2%) and C⋯O/ O⋯C (8.4%).In the crystal, the whole molecule of the title compound, C The title molecule Fig. 1 is nearlc-axis direction  to the Hirshfeld surface. The other large contributions to the Hirshfeld surface are from H⋯H , C⋯H/H⋯C  and C⋯O/O⋯C  interactions. All contributions to the Hirshfeld surface are listed in Table 3The Hirshfeld surface for the title molecule was performed and its associated two-dimensional fingerprint plots were prepared using et al., 2016H-imidazol-5-yl)methylidene]-1-methylhydrazinyl}pyridine methylidene]-1-methylhydrazinyl}-1H-benzimidazole monohydrate methylidene]hydrazinyl}-1H-benzimidazole hydrate unknown solvate -2-methylhydrazinylidene]methyl}-1H-imidazol-3-ium trifluoromethanesulfonate monohydrate methylene]-1-methylhydrazineyl}pyridin-1-ium) bis(trifluoromethanesulfonate) , an interesting example of a non-typical F⋯O interaction was found whose length, 2.859 (2) Å, is one of the shortest ever reported.Diazotization: 2.09 g (10 mmol) of dimethyl 5-aminoisophthalate were dissolved in 50 mL of water, the solution was cooled on an ice bath to 273 K and 0.69 g (10 mmol) of NaNO2 were added; 2.00 mL of HCl were then added in 0.5 mL portions over 1 h. The temperature of the mixture should not exceed 278 K.Azocoupling: NaOH  was added to a mixture of 10 mmol (1.28 g) of barbituric acid with 25.00 mL of water. The solution was cooled on an ice bath and a suspension of 3,5-bis(methoxycarbonyl)benzenediazonium chloride, prepared according to the procedure described above, was added in two equal portions under vigorous stirring for 1 h. The formed precipitate of the title compound was filtered off, recrystallized from methanol and dried in air. Crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution.The title compound: Yield, 68% (based on barbituric acid), yellow powder soluble in DMSO, methanol, ethanol and DMF. Analysis calculated for C14H12N4O7 (Mr = 348.27): C, 48.28; H, 3.47; N, 16.09; found: C, 48.25 H, 3.41; N, 16.03%. ESI–MS: m/z: 349.2 [Mr + H]+. IR (KBr): 3160, 3090 and 2846 ν(NH), 1745 and 1663 ν(C=O), 1610 ν(C=O⋯H) cm−1. 1H NMR (300.130 MHz) in DMSO-d6, internal TMS, δ (ppm): 8.20–8.36 , 11.32 , 11.54 , 14.08 . 13C{1H} NMR . δ: 55.6 (2OCH3), 119.54 (2Ar—H), 121.8 (Ar-H), 127.4 (2C—COOCH3), 133.25 (C=N), 142.87 (C—NHN=), 150.24 (C=O), 160.32 (C=O), 161.90 (C=O⋯H) and 166.56 (2COOCH3).Uiso(H) = 1.2 or 1.5Ueq(C). There is a small cavity in the crystal, which is only partially occupied by a water molecule, with an occupancy of 0.224 (5), and its hydrogen atoms could not be located.Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S2056989021006563/yk2153sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989021006563/yk2153Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021006563/yk2153Isup3.cmlSupporting information file. DOI: 2091530CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The two fused five-membered rings and their N-bound aromatic substituents form a pincer-like motif. In the crystal, a combination of C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π(ring) interactions leads to the formation of layers parallel to the  33H26N4O4, the two fused five-membered rings and their N-bound aromatic substituents form a pincer-like motif. The relative conformations about the three chiral carbon atoms are established. In the crystal, a combination of C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π(ring) interactions leads to the formation of layers parallel to the bc plane. A Hirshfeld surface analysis indicates that the most significant contributions to the crystal packing are from H⋯H (44.3%), C⋯H/H⋯C (29.8%) and O⋯H/H⋯O (15.0%) contacts.In the title compound, C The pyrrolooxazole fragment is folded along the C2⋯C5 axis by 62.63 (8)° while the dihedral angle between the C2/C3/N2/C4/C5 and C27–C32 rings is 67.11 (8)°. The C9–C14 and C15–C20 rings are inclined to the C6/C7/N3/N4/C8 ring by 32.32 (9) and 33.52 (9)°, respectively.A puckering analysis of the oxazole fragment  and Fig. 5b) show the front and back sides of the three-dimensional Hirshfeld surface of the title compound plotted over dnorm in the range −0.3067 to 1.6634 a.u. The red spots highlight the interatomic contacts, including the C—H⋯O hydrogen bonds.A Hirshfeld surface analysis and the associated two-dimensional fingerprint plots were performed with a–d, respectively. The other minor contributions to the Hirshfeld surface are by N⋯H/H⋯N (6.5%), C⋯C (1.8%), O⋯C/C⋯O (1.3%), N⋯O/O⋯N (0.5%), O⋯O (0.5%) and N⋯C/C⋯N (0.3%) contacts. The large number of H⋯H, C⋯H/H⋯C and O⋯H/H⋯O interactions suggest that van der Waals interactions and hydrogen bonding play the major roles in the crystal packing , C⋯H/H⋯C (29.8%) and O⋯H/H⋯O (15.0%) contacts Table 2 are illuR,7aS)-1,3,5,6,7,7a-hexahydro-3-(2-hydroxyphenyl)-1,1-diphenylpyrrolooxazol-6-ol benzenamine oxide  in toluene (15 ml) was heated at 373 K under reflux for 24 h, the reaction was monitored by TLC. The endo isomer was filtered off as a major product. The title compound was recrystallized from a mixture of toluene and petroleum ether as colorless crystals in 60% yield; mp: 469–471 K.A mixture of Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989021002358/ex2041sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989021002358/ex2041Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021002358/ex2041Isup3.cmlSupporting information file. DOI: 2067379CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


To predict the clinical manifestations of α-globin gene aberration for genetic counseling, we examined the prevalence of the α-globin triplication and the genotype–phenotype correlation in this subpopulationA cohort of 7644 subjects was selected from nine ethnicities covering four regions in Guizhou province of China. Peripheral blood was collected from each participant for routine blood testing and hemoglobin electrophoresis. PCR-DNA sequencing and Gap-PCR were used to identify the thalassemia gene mutations. Chi-square tests and one-way analysis of variance (ANOVA) were used to statistically analyze the data.anti4.2/αα accounted for 0.523% (40/7644), the αααanti3.7/αα for 0.235% (18/7644), and the αααanti3.7/–SEA for 0.013% (1/7644). The αααanti4.2/αα is more prevalent than the αααanti3.7/αα in Guizhou. In addition, the frequency of the HKαα/αα (that by GAP-PCR is like αααanti4.2/-α3.7) was 0.235% (18/7644). Ethnically, the Tujia group presented the highest prevalence (2.47%) of α-globin triplication. Geographically, the highest frequency of the α-globin triplication was identified in Qiannan region (2.23%). Of the triplicated α-globin cases, 5 coinherited with heterozygote β-thalassemia and presented various clinical manifestations of anemia.We found that the frequency of α-globin triplication in Guizhou province was 0.772% (59/7644). Genotypically, the αααThese data will be used to update the Chinese triplicated α-globin thalassemia database and provide insights into the pathogenesis of thalassemia. These findings will be helpful for the diagnosis of thalassemia and future genetic counseling in those regions. Based oαanti4.2 , 12. Theulations –13. In aunctions , 15. ButGuizhou province, located in southwestern China, is one of the regions with the highest rate of α-thalassemia in Asia . The popGuizhou province contains four regions. Two representative counties/cities from each region were taken for study. Inclusion criteria: subjects whose residence in these regions exceeded 3 years at the time of recruitment, regardless of age, sex, and ethnicity. In total, 7866 participants were recruited by simple random sampling method from 8 counties/cities  in four regions  of Guizhou province in China from February 2014 to June 2016. Eventually, blood samples and health information were collected from 7644 qualified people for investigation based on the inclusion criteria  and hemoglobin electrophoresis .http://www.HGVS.org/varnomen).Approximately 3 ml of peripheral blood was collected from each subject. DNA extraction was conducted by using the Magen nucleic acid extraction kit . Four pairs of globin gene specific PCR primers  were designed and synthesized by the Beijing Genome Institute (BGI)-Shenzhen. For identification of HKαα, next-generation sequencing plus Gap-PCR were adopted. All the globin gene-specific PCR primers were owned and patented by the BGI-Shenzhen, and unpublicized. PCR was carried out in a volume of 25 μl with an amplification reaction system containing 1 pair of tag primers, 50–200 ng DNA, and 2 × Gold Star Taq Master Mix (Kangwei century). The PCR amplification was performed using the ABI9700 . The PCR conditions: 95 °C 10 min; 95 °C 30 s, 60 °C 30 s, 72 °C 50 s, 35 cycles; 72 °C 5 min, 15 °C hold; PCR conditions for copy number variations: 95 °C 10 min; 95 °C 30 s, 60 °C 60 s, 24 cycle; 15 °C hold. Whole genome DNA sequencing was performed to detect globin gene defects by the Beijing Genome Institute (BGI)-Shenzhen through next-generation sequencing technology . Gap-PCRContinuous variables are summarized by descriptive statistics, including the mean and range or standard deviation. Categorical variables are presented as number and percentage, and the comparisons of frequencies and mean were completed by using the Chi-square test and one-way analysis of variance (ANOVA). A statistically significant difference was defined as a p < 0.05. Statistical analyses were performed with SPSS 17.0 .Of the 7644 qualified participants, 3817 were males and 3827 were females, the participants’ ages ranged from 5 to 68 (average age 25 ± 3.4) years, 1027 (13.44%) were minors, and 6617 (86.56%) were adults. The geographical residence pattern of the subjects was as follows: Qianbei  region, 2904 (37.99%); Qiannan , 491 (6.42%); Qianxi , 952 (12.45%); and Qiandongnan , 3297 (43.13%). There were nine ethnicities inhabiting those regions: Han, 4475 (58.5%); Dong, 890 (11.6%); Miao, 737 (9.6%); Buyi, 486 (6.4%); Shui, 325 (4.3%); Tujia, 243 (3.2%); Yao, 151 (2%); Gelao, 141 (1.8%); and Zhuang 196 (2.6%).anti4.2/αα accounted for 0.523% (40/7644), the αααanti3.7/αα for 0.235% (18/7644), and 1 subject carried a αααanti3.7 allele and a –SEA allele (genotype: αααanti3.7/–SEA), accounting for 0.013% (1/7644). Thus, the αααanti4.2/αα is more prevalent than the αααanti3.7/αα in Guizhou province (p < 0.05). In addition, we identified 18 cases of the HKαα/αα carriers, accounting for 0.235% (18/7644).As listed in Table anti4.2/αα was identified in the Tujia ethnic group (1.65%), followed by the Han, Dong, Shui, Buyi, and Miao. The frequency of the αααanti4.2/αα in the Tujia group was significantly higher than in the Miao (p = 0.015), Dong (p = 0.022), and Buyi (p = 0.045). For the αααanti 3.7/αα genotype, the highest rate was observed in the Tujia group as well, followed by the Dong, Han, Buyi, and Miao. No αααanti 3.7/αα carrier was observed in the Shui group. No triplicated α-globin genes were detected in the Zhuang, Yao, and Gelao groups.As listed in Table p = 0.03), Qianbei (p = 0.001), and Qianxi (p = 0.0045). There was no significant difference observed between the other regions. While the prevalence of the αααanti 4.2/αα genotype was significantly higher in Qiannan region than in other regions, the αααanti3.7/αα was commonly found in Qiannan and Qiandongnan regions. However, although the frequency of the αααanti3.7/αα was higher in Qiandongnan, there was no statistically significant distribution difference between those regions (p > 0.05). In addition, the HKαα/αα was mainly distributed in Qiandongnan, but its distribution had no statistically significant difference between those regions (p > 0.05). The αααanti3.7/– SEA was quite rare in those regions, and only one case was detected in Qiandongnan.As listed in Table anti3.7/–SEA case, and 18 cases of the HKαα/αα did not presented any clinical manifestations such as anemia at the time of examination. The blood parameters including the red blood cells (RBC), hemoglobin (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), HbA, HbA2, and HbF were measured and statistically analyzed through ANOVA. No significant parameter difference was identified among the three different genotype groups (p > 0.05) (Tables 0 (HBB: c.126_129delCTTT) and αα/αααanti4.2 (Table 0 (HBB:c.52A > T) and the αα/αααanti4.2.The frequency of thalassemia-gene carriers in Guizhou is 11.03%, with 7.41% of α-thalassemia-gene frequency and 3.23% of β-thalassemia-gene frequency (unpublished data). Therefore, the frequency of α-thalassemia is higher than β-thalassemia in Guizhou province, China. While deletion of α-globin genes causes α-thalassemia, the triplicated α-globin genes alone rarely cause obvious clinical symptoms. All 59 carriers of the triplicated α-globin genes including the αααanti4.2/αα, αααanti3.7/αα. Although the HKαα shows by GAP-PCR the positivity for αααanti4.2 and -α3.7, it is not considered as α-globin triplication due to no real extra copy of the α-globin gene existed in the HKαα allele. Observations have indicated that α-globin triplication alone does not cause detectable clinical manifestations [anti3.7 and αααanti4.2 was different between the two subpopulations. In our study, the ratio of αααanti3.7/αααanti4.2 was 0.47 (0.248% αααanti3.7/0.523% αααanti4.2) in Guizhou province, while it was 3.0 (0.9% αααanti3.7/0.3% αααanti4.2) in Guangdong province. This finding suggests that the αααanti4.2 triplication is rather common in Guizhou, while the αααanti3.7 is prevalent in Guangdong region.To date, at least two genotypes of α-globin triplication have been described: αααstations . Howeverstations , and in anti4.2 in Tujia was significantly higher (1.65%) than in any other ethnic group. This is the first report that Tujia have a higher frequency of α-globin triplication. Whether this higher rate of α-globin triplication is caused by a founder effect or not requires further investigation. Although previous studies have reported that the frequencies of α-globin defects in the Zhuang and Yao ethnic groups were significantly higher than that in the Han ethnic group in Guangxi, another province in southwestern China [Ethnically, the Tujia group presented the highest prevalence (2.47%) of the α-globin triplication. In particular, the prevalence of αααrn China , we did anti4.2 in Qiannan was also higher than in other regions. The other type of α-globin triplication, αααanti3.7/–SEA, and the non-α-triplication HKαα/αα had no significant geographical differences. In addition, we did not identify any anti-HKαα allele, although we found that the frequency of HKαα allele was 0.235%, significantly higher than previously reported. To exclude the presence of HKαα in case of positivity for the -α3.7 and αααanti4.2, next-generation and Gap-PCR are needed to be simultaneously performed. Interestingly, while the HKαα is hardly observed in other regions, it was relatively common in Qiandongnan and its frequency is comparable to that of the αααanti 4.2 triplication there . The frequency difference of the α-globin triplication between Qiannan and any other region was statistically significant. Moreover, the frequency of ααα%. The franti4.2, and αααanti3.7 carriers were all within the normal range, which is consistent with previous reports [anti4.2, and αααanti3.7 will not present clinical manifestations such as anemia. Of note, although the HKαα carriers presented a normal range of hematological parameters, their RBC, hemoglobin, MCH, and MCV were all slightly lower than the αααanti4.2 and αααanti3.7 carriers, implying that the particular cluster structure that could reduce the α-globin gene expression.In our study, the hematological parameters and hemoglobin electrophoresis data of the HKαα, ααα reports , 22. Theanti3.7/–SEA did not presented any clinical manifestations such as anemia at the time of examination, which is consistent with previous reports [As mentioned above, the triplicated α-globin genes alone barely lead to detectable clinical phenotypes. In this study, of the 59 cases of α-globin genes triplication, 5 cases coinherited with β-globin gene mutation(s) while the other 54 subjects did not present any clinical symptoms. Although many reports have stated that α-globin triplication can exacerbate the symptoms of β-thalassemia, the issue is still controversial because the expected worsened anemia has not occurred in all cases , 18. In  reports , 23.Currently, Gap-PCR and PCR combined with RDB (reverse dot blot) methods are commonly used to detect α-globin gene deletions and the β-globin gene defects, but they usually miss the triplicated α-globin genes. In this study, whole genome NGS combined with Gap-PCR was adopted to screen for all types of α-globin and β-globin gene alterations, including α-globin gene deletion, triplication, splicing mutations, which would be expected to increase the detection sensitivity and improve the diagnosis of β-thalassemia.This epidemiological study has identified the current α-triplication genotypes and their prevalence and distribution in Guizhou province, which will be used to update the triplicated α-globin thalassemia database, provide insights into the pathogenesis of thalassemia and shed light on the diagnosis of thalassemia in southwestern China.


The title compound crystallizes with half of a molecule per asymmetric unit and exhibits bond lengths and angles typical of α-diketones. A network of C—H⋯F contacts and π–π stacking interactions is observed within the structure. 14H6F4O2, crystallizes with half of a molecule per asymmetric unit and exhibits bond lengths and angles typical of α-diketones. A network of C—H⋯F contacts and π–π stacking interactions is observed within the structure.The title compound, C The title α-diketone, 1,2-bisethane-1,2-dione, is used as a precursor in the production of hexabenzocoronenes  and similar α,α-diketones crystallize in trigonal or monoclinic space groups, respectively , and exhibits the expected bond lengths and angles for α-diketone sp2 hybridized atoms. Interestingly, the C5—C6—C7—O1 torsion angle [7.55 (19)°] of the title compound is larger compared to the same torsion angle in bis(4-fluorophenyl)ethane-1,2-dione . A network of C—H⋯O interactions is also observed between the carbonyl oxygen and H5. This interaction is significantly weaker for 1,2-bisethane-1,2-dione in comparison to benzil (O⋯H = 2.42 Å) and bis(4-fluorophenyl)ethane-1,2-dione (O⋯H = 2.40 Å). As a result, the π–π stacking and C—H⋯ F interactions play a vital role in how the compound packs within the crystal structure.A view of crystal packing of the title compound is presented in Fig. 2ne Fig. 3. Similaret al., 2016A search of the Cambridge Structural Database pentane-1,4-dione.Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989021005363/yk2148sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989021005363/yk2148Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021005363/yk2148Isup3.cdxSupporting information file. DOI: Click here for additional data file.10.1107/S2056989021005363/yk2148Isup4.cmlSupporting information file. DOI: 2085161CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond between the hydroxy substituent on the benzene ring and one of the carbonyl groups of the acridinedione unit. 27H33NO5, a 3,3,6,6-tetramethyltetrahydroacridine-1,8-dione ring system carries an ethyl acetate substituent on the acridine N atom and an o-hydroxyphenyl ring on the central methine C atom of the dihydropyridine ring. The benzene ring is inclined to the acridine ring system at an angle of 80.45 (7)° and this conformation is stabilized by an intramolecular O—H⋯O hydrogen bond between the hydroxy substituent on the benzene ring and one of the carbonyl groups of the acridinedione unit. The ester C=O oxygen atom is disordered over major and minor orientations in a 0.777 (9):0.223 (9) ratio and the terminal –CH3 unit of the ethyl side chain is disordered over two sets of sites in a 0.725 (5): 0.275 (5) ratio. In the crystal, C—H⋯O hydrogen bonds combine to link the molecules into a three-dimensional network. van der Waals H⋯H contacts contribute the most to the Hirshfeld surface (66.9%) followed by O⋯H/H⋯O (22.1%) contacts associated with weak hydrogen bonds.In the title compound, C In contrast, the central C13/N1/C1/C6–C8 ring can best be described as a flattened boat with N1 and C7 displaced by 0.146 (1) and 0.191 (14) Å, respectively, from the remaining four C atoms. The bond lengths and angles in the title molecule agree reasonably well with those found in closely related molecules . The relative contributions of the other interactions in descending order are: O⋯H/H⋯O (22.1%), C⋯H/H⋯C (9.2%), O⋯O (1.3%), N⋯H/H⋯N (0.2%) and N⋯C/C⋯N (0.2%). This illustrates that the C—H⋯O interactions contribute significantly to the crystal packing.The overall two-dimensional fingerprint plot is illustrated in Fig. 4ts Fig. 4b. The rH)-yl]acetic acid [Cambridge Structural Database -yl]acetate -dione -dione -1,8-dioxo-2,3,4,5,6,7,8,9-octahydroacridin-10(1S(8) ring. In the crystal, the molecules are linked by O—H⋯O, C—H⋯O and C—H⋯π interactions, forming a three-dimensional network. In VANBUK, the central 1,4-dihydropyridine ring adopts a shallow sofa conformation (with the C atom bearing the bromophenol ring as the flap), whereas the pendant cyclohexene rings both have twisted-boat conformations. The molecule features an intramolecular O—H⋯O hydrogen bond, which closes an S(8) ring. In the crystal, molecules are linked by C—H⋯O interactions, forming C(12) chains propagating along the c-axis direction. In the crystal of SILBIB, O—H⋯O, C—H⋯O and C—H⋯π(ring) hydrogen bonds combine with an Br—O and unusual C—Br⋯π(ring) halogen bonds to generate a three dimensional network with molecules stacked along the a-axis direction. In the acridinedione moiety of PUSJEU, the central dihydropyridine ring adopts a flattened-boat conformation, with the N atom and the methine C atom displaced from the mean plane of the other four atoms by 0.0513 (14) and 0.1828 (18) Å, respectively. The two cyclohexenone rings adopt envelope conformations, with the tetrasubsituted C atoms as the flap atoms. In the crystal, molecules are linked via a pair of C—H⋯O hydrogen bonds, forming inversion dimers, which are, in turn, linked by C—H⋯O hydrogen bonds, forming slabs lying parallel to (001).The DABSAD compound crystallizes with two molecules in the asymmetric unit. In each molecule, the central 1,4-dihydropyridine ring adopts a shallow sofa conformation (with the C atom bearing the phenol ring as the flap), whereas the pendant cyclohexene rings both have twisted-boat conformations. Each molecule features an intramolecular O—H⋯O hydrogen bond, which closes an To a mixture of dimedone , ethyl glycinate hydrochloride  and salicaldehyde  in ethanol (20 ml), triethyl amine  was added. The reaction mixture was heated under reflux for 5 h at 353–358 K then left to cool. The separated solid was filtered off, dried and recrystallized from ethanol solution as yellow plates of the title compound, yield 68%, m.p. 497 K.Uiso(H) = 1.2Ueq (C) and O—H = 0.84 Å, Uiso(H) = 1.5Ueq (O). Atom O3 of the oxo group and terminal methyl group (C17) of the ethyl acetate substituent are disordered over two sites in 0.777 (9):0.223 (9) (for O3 and O3A) and 0.725 (5):0.275 (5) (for C17 and C17A) ratios, respectively.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989021001341/hb7967sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989021001341/hb7967Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021001341/hb7967Isup3.cmlSupporting information file. DOI: 2061379CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


A linear supramolecular chain featuring amine-N—H⋯O(nitro) hydrogen bonding is noted in the crystal.The N 22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetrahedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethylene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitrobenzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitrobenzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supramolecular chain along the b-axis direction features amine-N—H⋯O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C—H⋯O(nitro) and π(chelate ring)–π(phenyl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C—H⋯O(nitro) and nitro-O⋯π(phenyl) interactions.The title zinc bis(thiosemicarbazone) complex, [Zn(C These ligands usually act as monodentate or bidentate ligands and coordinate with transition and non-transition metal ions either in neutral or anionic form through thione/thiolate-sulfur and azomethine/imine-nitrogen donor atoms ° for the S1—Zn—N1 chelate angle, to a wide 131.16 (2)°, for S1—Zn—S2, consistent with an approximate tetrahedral geometry. The mode of coordination of the thiosemicarbazone ligands leads to the formation of five-membered chelate rings. These are nearly planar with r.m.s. deviations of 0.0459 and 0.0152 Å for the S1- and S2-containing rings, respectively. However, the maximum deviation from the plane through the S1-chelate ring of −0.0613 (9) Å for the N1 atom suggests an alternate description of the conformation of the S1-ring might be valid. Another description might be an envelope conformation with the zinc atom lying 0.209 (3) Å out of the plane of the four remaining atoms (r.m.s. deviation = 0.0005 Å). The dihedral angle between the mean plane through the rings is 73.28 (3)°. There are three formal double bonds in each thiosemicarbazone anion. Owing to chelation, the configuration about the endocyclic imine bond is Z whereas that about the exocylic imine bond is E; the configuration of the ethylene bond is E.The molecular structure of (I)N-bound phenyl and nitrobenzene rings is 72.41 (5), 16.96 (11) and 40.48 (6)°, respectively, for the S1-ring compared with 82.47 (6), 20.33 (5) and 13.18 (4)°, respectively, for the S2-ring. Similarly, the pairs of dihedral angles between the imine- and N-bound phenyl rings, i.e. 59.15 (6) and 76.48 (8)°, and N-bound phenyl and nitrobenzene rings, i.e. 43.23 (8) and 22.64 (4)°, show notable differences; the dihedral angles between the imine-phenyl and nitrobenzene rings are comparable, i.e. 82.28 (7) and 85.67 (7)°. Finally, the nitro groups present different relative orientations with respect to the benzene rings they are connected to, with the N4-nitro group being twisted out of the plane. This is shown in the value of the C2—C3—N4—O1 torsion angle of 161.88 (18)° compared with −0.4 (3)° for the C26—C25—N8—O3 torsion angle.Some major differences are noted in the conformations of the ligands. Thus, the sequence of dihedral angles formed between the chelate ring and the imine-phenyl, b-axis direction, Table 2a). The hydrogen bonds involve the N7-amine, there being no apparent role for the N3-amine in the supramolecular aggregation. A phenyl-C44—H⋯O4(nitro) contact provides extra stability to the chain and indicates the nitro-O4 atom forms two contacts. Chains assemble about the 21-screw axis via a combination of phenyl-C37—H⋯O3(nitro) and π–π contacts. The π–π contacts are of particular interest in that the participating rings are a phenyl and a chelate ring, as highlighted in Fig. 2b); such interactions are now well recognized in the supramolecular chemistry of metal complexes and impart significant energies of stabilization to the packing ⋯Cgi is 3.5559 (11) Å with an inter-planar angle = 6.70 (8)° and slippage of 0.34 Å for symmetry operation (i): x, y, z. The links between chains to consolidate the three-dimensional architecture are of the type phenyl-C14—H⋯O1(nitro) and nitro-O1⋯π(phenyl), Table 2Cg(C23–C28)ii = 3.4788 (19) Å with angle at O1 = 108.71 (13)° for (ii): 1 − x, 1 − y, 1 − z. A view of the unit-cell contents is shown in Fig. 3Conventional amine-N7—H⋯O4(nitro) hydrogen bonds are noted in the crystal of (I)Crystal Explorer 17 dnorm-mapped Hirshfeld surface of Fig. 6dnorm-mapped Hirshfeld surface. However, the π–π interaction appears as a flat surface on the curvedness-mapped Hirshfeld surface of Fig. 8a), the nitro-O⋯π interaction is shown as red concave and blue bump regions on the shape-index-mapped Hirshfeld surface of Fig. 8b).The faint-red spots observed on the a)–(f), respectively. The percentage contributions from each interatomic contact are summarized in Table 4b), with the peak tipped at de = di ∼2.2 Å corresponding to the H24⋯H44 contact, Table 3de + di ∼2.0 and 2.6 Å, respectively, Fig. 9c) and (d). The H⋯S/S⋯H contacts contribute 8.6% and appear as two blunt-symmetric wings at de + di ∼2.9 Å in Fig. 9e). This feature reflects the long-range H⋯S/S⋯H contact evinced in the packing with a separation of 0.1 Å shorter than the sum of their van der Waals radii, Table 3de + di ∼2.6 Å in the fingerprint plot of Fig. 9f), the contribution to the overall Hirshfeld surface is only 5.2%. The other 11 interatomic contacts have a negligible effect on the molecular packing as their accumulated contribution is below 11%, Table 4The overall two-dimensional fingerprint plot for (I)d,p) level of theory. The total energy (Etot) was calculated by summing four energy components, comprising the electrostatic (Eele), polarization (Epol), dispersion (Edis) and exchange-repulsion (Erep) energies. The independent energy components as well as the Etot are tabulated in Table 5Edis energy term still makes the major contribution to the interaction energies partly due to the presence of π–π, N—O⋯π, C—H⋯O and C—H⋯C interactions. The total Edis components of all pairwise interactions sum to −432.1 kJ mol−1, whereas the total Eele sums to −190.2 kJ mol−1. The stabilization of the crystal through the contribution of the dispersion forces is emphasized by the energy framework diagram, Fig. 10b axis.The pairwise interaction energies between molecules in the molecular packing of (I)N-bound ethyl species with a terminal phenyl ring -N-phenylhydrazine-1-carbothioamide, (VI), was filtered, washed with cold ethanol and dried in vacuo after which it was used without further purification. Compound (VI)  was dissolved in hot absolute ethanol (50 ml), which was added to a solution of Zn(CH3COO)2·2H2O  in hot absolute ethanol (40 ml). The mixture was heated (348 K) and stirred for about 10 min, followed by stirring for about 1 h at room temperature. The white precipitate obtained was filtered, washed with cold ethanol and dried in vacuo. Single crystals were grown at room temperature by slow evaporation of (I)v/v 20 ml). Yield: 90%, m.p. 511–512 K. FT–IR (ATR (solid) cm−1): 3428 ν(N—H), 1593 ν(C=N), 1335 ν(N—N), 579 ν(Zn—N), 489 ν(Zn—S). UV–Visible: λmax ): 250 , 292 , 433 . ICP–AES: Experimental %Zn = 7.26, Theoretical %Zn = 7.53.Analytical grade reagents were used as procured and without further purification. 4-Phenyl-3-thiosemicarbazide  and 4-nitrochalcone  were dissolved separately in hot absolute ethanol (50 ml) and mixed while stirring. About five drops of concentrated hydrochloric acid were added to the mixture and the mixture was heated (348 K) while stirring for about 30 min. The yellow precipitate, (2Uiso(H) set to 1.2Ueq(C). The N-bound H atoms were located in a difference-Fourier map, but were refined with an N—H = 0.88±0.01 Å distance restraint, and with Uiso(H) set to 1.2Ueq(N).Crystal data, data collection and structure refinement details are summarized in Table 710.1107/S2056989021007398/mw2178sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989021007398/mw2178Isup2.hklStructure factors: contains datablock(s) I. DOI: 2097106CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The dihedral angle between the aromatic rings in the title compound is 31.84 (8)°; N—H⋯O and C—H⋯O hydrogen bonds and π–π stacking interactions connect molecules in the crystal, producing a three-dimensional network. 16H12F5N3O, the dihedral angle between the aromatic rings is 31.84 (8)°. In the crystal, the molecules are linked into dimers possessing crystallographic twofold symmetry by pairwise N—H⋯O hydrogen bonds and weak C—H⋯O hydrogen bonds and aromatic π–π stacking interactions link the dimers into a three-dimensional network. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from F⋯H/H⋯F (41.1%), H⋯H (21.8%), C⋯H/H⋯C (9.7%) C⋯C (7.1%) and O⋯H/H⋯O (7.1%) contacts. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine  in PLATON. The solvent contribution was not included in the reported molecular weight and density.In the title compound, CSpek 2015. Acta Cr R)C=N—NHR grouping possess controllable E/Z isomerization around the C=N double bond, which makes them good candidates for the construction of functional materials  Å. The backbone of the molecule is non-planar with a dihedral angle of 31.84 (8)° between the C1–C6 pentaflourobenzene and C11–C16 benzene rings and the acetamide group lies almost perpendicular. The C5—C6—C7—N2, C6—C7—N2—N3, C7—N2—N3—C11, N2—N3—C11—C16 and C6—C7—C8—N1 torsion angles are −28.19 (17), 174.02 (10), −176.33 (11), 5.90 (18) and 122.80 (12)°, respectively.The title molecule Fig. 1 crystallCg1⋯Cg1b = 3.7137 (10) Å, slippage = 1.158 Å, Cg1⋯Cg2b = 3.7015 (9) Å, slippage = 1.407 Å, and Cg1⋯Cg2a = 3.7016 (9) Å, slippage = 1.148 Å; where Cg1 and Cg2 are the centroids of the C1–C6 and C11–C16 rings, respectively; symmetry codes: (a) 1 − x, y, z; (b) 1 − x, 1 − y, 1 − z]. Together, these generate a three-dimensional network  in blue and negative electrostatic potential is indicated in red (hydrogen-bond acceptors).a. The percentage contributions to the Hirshfeld surfaces from various interatomic contacts (Table 2b), H⋯H , C⋯H/H⋯C  C⋯C  and O⋯H/H⋯O . Other contact types including N⋯H/H⋯N, N⋯C/C⋯N and N⋯N contacts account for less than 5.4% of the Hirshfeld surface mapping and presumably have minimal directional impact on the packing.The overall two-dimensional fingerprint map for the title compound is shown in Fig. 4s Table 2 are F⋯H/s Table 2b, H⋯H -1-benzylidene-2-phenylhydrazine skeleton are (E)-3-chloro-N′-(2-fluorobenzylidene)thiophene-2-carbohydrazide ethylidene]isonicotinohydrazide -bis[(thiophen-2-yl)methylidene]hydrazine ethylidene]nicotinohydrazide  Å. The molecular skeleton is approximately planar, the terminal five- and six-membered rings forming a dihedral angle of 5.47 (9)°. In the crystal, molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds into zigzag chains propagating in [100].The hydrazide derivative SOJQAL adopts an E conformation with respect to the azomethine bond. The pyridyl and fluorobenzene rings make dihedral angles of 38.58 (6) and 41.61 (5)° respectively with the central C(=O)N2CC unit, resulting in a non-planar molecule. The intermolecular interactions comprise two classical N—H⋯O and N—H⋯N hydrogen bonds and four non-classical C—H⋯O and C—H⋯F hydrogen bonds. These interactions are augmented by a weak π–π interaction between the benzene and pyridyl rings of neighbouring molecules, with a centroid–centroid distance of 3.9226 (10) Å. This leads to a three-dimensional supramolecular assembly in the crystal.The molecule of HIXRAJ adopts an The asymmetric unit of MIHROK03 comprises two independent half-molecules, each residing on a centre of symmetry. The two molecules are essentially planar. In the crystal, weak C—H⋯π interactions join the two symmetry-independent molecules into interlinked chains parallel to [011].E conformation with respect to the azomethine double bond whereas the N and methyl C atoms are in a Z conformation with respect to the same bond. The ketonic O and azomethine N atoms are cis to each other. The non-planar molecule [the dihedral angle between the benzene rings is 7.44 (11)°] exists in an amido form with a C=O bond length of 1.221 (2) Å. In the crystal, a bifurcated N—H⋯ hydrogen bond is formed between the amide H atom and the keto O and imine N atoms of an adjacent molecule, leading to the formation of chains propagating along the b-axis direction.The molecule of ZISSAX adopts an via hydrogen bonding of the carboxyl groups. In addition, there is an N—H⋯O hydrogen bond between the amino group and the carbonyl O atom.In TINWIX, the aromatic rings are almost perpendicular, making a dihedral angle of 89.26 (5)°. The carboxyl group is coplanar with the aromatic ring to which it is attached [dihedral angle = 1.70 (17)°]. The packing involves inversion-symmetric dimers bridged E)-1-[(perfluorophenyl)methylene]-2-phenylhydrazine , tetramethylethylenediamine (TMEDA) , CuCl  and CCl4 . After 1–3 h , the reaction mixture was poured into a 0.01 M solution of HCl , and extracted with dichloromethane (3 × 20 ml). The combined organic phase was washed with water (3 × 50 ml), brine (30 ml), dried over anhydrous Na2SO4 and concentrated in vacuo using a rotary evaporator. The residue was purified by column chromatography on silica gel using appropriate mixtures of hexane and dichloromethane (3/1–1/1). Colourless prisms of the title compound suitable for X-ray analysis were obtained by slow evaporation of a dichloromethane solution (69%); m.p. 405 K. Analysis calculated for C16H12F5N3O: C 53.79, H 3.39, N 11.76; found: C 53.73, H 3.36, N 11.71%. 1H NMR  δ 3.04 , 6.50–7.33 . 13C NMR  δ 33.58, 108.97, 116.87, 120.75, 124.11, 124.76, 140.95, 146.33, 149.87, 150.91, 155.21. ESI–MS: m/z: 358.24 [M + H]+.A 20 ml screw-neck vial was charged with DMSO (10 ml), (Uiso(H) = 1.2 or 1.5Ueq (C). The residual electron density was difficult to model and therefore the SQUEEZE routine  contains approximately three electrons.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989021007349/hb7979sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989021007349/hb7979Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021007349/hb7979sup3.docxElectrostatic potential map. DOI: Click here for additional data file.10.1107/S2056989021007349/hb7979Isup4.cmlSupporting information file. DOI: 1878189CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


III complex was synthesized from the substitution reaction between the (ppy)2Ir(μ-Cl)2Ir(ppy)2  dimer and 1,1-bis(diphenylphosphanyl)methane  under an argon gas atmosphere. The IrIII atom is coordinated by two C,N-bidentate ppy anions, a unidentate dppm ligand and a chloride anion in a distorted octahedral IrC2N2PCl arrangement.The title Ir III complex, [Ir(C11H8N)2Cl(C25H22P2)], was synthesized from the substitution reaction between the (ppy)2Ir(μ-Cl)2Ir(ppy)2  dimer and 1,1-bis(diphenylphosphanyl)methane  under an argon gas atmosphere for 20 h. The IrIII atom is coordinated by two C,N-bidentate ppy anions, a unidentate dppm ligand and a chloride anion in a distorted octahedral IrC2N2PCl arrangement. The N donor atoms of the ppy ligands are mutually trans while the C atoms are cis. Intramolecular aromatic π–π stacking between the phenyl rings of ppy and dppm, and C—H⋯Cl interactions are observed. In the crystal, C—H⋯Cl and C—H⋯π contacts link the molecules into a three-dimensional network. A Hirshfeld surface analysis was carried out to further quantify the intermolecular interactions, and indicated that H⋯H contacts (63.9%) dominate the packing.The title Ir The bond lengths of Ir1—N1, Ir1—N2, Ir1—C11 and Ir1—C22 are 2.051 (2), 2.062 (2), 2.004 (3) and 2.032 (3) Å, respectively. As expected, the averaged Ir–C and Ir—N bond lengths are much shorter than the Ir—Cl and Ir—P bonds, based on the sizes of the different species.The asymmetric unit of (I)2(dppm)]PF6 e.g., Hao et al., 20192(dppm)](PF6) iridium(III) are reported to be 2.503 (19) trans bond angles deviate from the ideal 180° [170.97 (9)–175.37 (8)°], similar to related compounds methane (dppm) often occurs as a bidentate ligand (Cg5⋯Cg7 = 3.621 (1) Å and between the phenyl rings of the dppm molecule (C29–C34 and C36–C41), Cg8⋯Cg9 = 3.997 (1) Å  Å], C30—H30⋯Cl1 [C⋯Cl = 3.664 (4) Å] and C35—H35A⋯Cl1 [C35⋯Cl = 3.460 (3) Å]  Å Fig. 2. Three wÅ] Fig. 3 are obse⋯π (ring) interactions are found in the crystal packing  of the C17–C22 phenyl ring (H3⋯Cg6 = 2.83 Å). In addition, C—H⋯π(ring) interactions are also found between the dppm phenyl rings of neighbouring molecules: C26—H26 ⋯Cg10 , C38—H38⋯Cg10 (H38⋯Cg10 = 2.81 Å) and C40—H40⋯Cg8 (H40⋯Cg8 = 2.95 Å). In addition, pairwise intermolecular hydrogen bonds are observed between C14—H14 of the pyridine ring of the ppy ring and Cl1  with the functions de and di, which are the distances from an indicated area on the Hirshfeld surface to the nearest atoms outside and inside the surface, respectively. The white, red, and blue areas on the dnorm-mapped Hirshfeld surfaces show intermolecular contacts that are equal to, shorter than, and longer than the sum of their van der Waals (vdW) radii, respectively. A pair of intermolecular contacts are shown as red spots on the Hirshfeld surface close to the Cl1 atom of the adjoining molecule and the H14 atom of the associated pyridine ring. The spots indicate hydrogen-bond donor-to-acceptor interactions of C14—H14⋯Cl1 and vice versa  while Fig. 6b)–(d) depict the contacts of the H⋯H (63.9%), C⋯H/H⋯C (29.5%) and H⋯Cl/Cl⋯H (4.4%) interactions, respectively.Additional insights into the weak intermolecular contacts in the crystal packing of (I)sa Fig. 5. The relSciFinder ]+; dppm = bis(diphenylphosphanyl)methane bidentate ligand. However, none of the remaining publications describe a monomeric IrIII complex similar to the title compound. The seven hits include the octahedral crystal structures of IrIII complexes with a bis(2-phenylpyridine)iridium(III) backbone and ancillary ligands of both N-donor, P-donor and O-donor ligands. There are a tris-complex of Ir(ppy)3 ]; dppel = 1,2-bis(diphenylphosphanyl)ethylene, [Ir(ppy)2(dppp)]; dppp = 1,3-bis(diphenylphosphanyl)propane and [Ir(ppy)2(dppe)]; dppe = 1,2-bis(diphenylphosphanyl) ethane] ]PF6, [Ir(dfppy)2(P^N)]PF6 and [Ir(dfmppy)2(P^N)]PF6 where P^N = 2-[(diphenylphosphanyl) methyl]pyridine, dfppy = 2-pyridine and dfmppy = 2--4-methylpyridine ]PF6    and refined as riding with Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989021000955/hb7961sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989021000955/hb7961Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989021000955/hb7961Isup3.molSupporting information file. DOI: 2058995CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


In the crystal, molecules are linked by C—H⋯O hydrogen bonds, generating  22H15N3O4, is built up from a central imidazopyridine ring system connected to a nitroso group, a phenyl ring and a 2-oxo-2-phenylethyl acetate group. The imidazo pyridine ring system is almost planar (r.m.s. deviation = 0.017 Å) and forms dihedral angles of 22.74 (5) and 45.37 (5)°, respectively, with the phenyl ring and the 2-oxo-2-phenylethyl acetate group. In the crystal, the molecules are linked into chains parallel to the b axis by C—H⋯O hydrogen bonds, generating R21 (5) and R44 (28) graph-set motifs. The chains are further linked into a three-dimensional network by C—H⋯π and π-stacking interactions. The intermolecular interactions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.5%), H⋯O/O⋯H (20.0%), C⋯O/O⋯C (6.5%), C⋯N/N⋯C (6.2%), H⋯N/N⋯H (4.5%) and C⋯C (4.3%) interactions.The title compound, C N-heterocycles as the core structure, including imidazopyridine and its derivatives, which are used in medicinal chemistry Numerous drugs contain a] pyridine ring system is planar with an r.m.s deviation of 0.017 Å and a maximum deviation of 0.028 (1) Å for atom C11. The mean plane through the fused ring system makes dihedral angles of 22.74 (5) and 45.37 (5)° with the phenyl ring (C1–C6) and the 2-oxo-2-phenylethyl acetate group (C14–C22), respectively. The dihedral angle between the two aromatic rings (C1–C6 and C17–C22) is 59.63 (5)°. The molecular conformation is stabilized by two weak intramolecular C9—H9⋯O1 and C1—H1⋯N1 hydrogen bonds, generating S(6) ring motifs (Table 1The molecular structure of (I)s Table 1.iii and C10—H10⋯O2iii hydrogen bonds, forming chains that propagate parallel to the b axis and enclose A⋯O4i and C15—H15B⋯O1ii hydrogen bonds with Cg4iv interaction (Cg4 is the centroid of the C17–C22 phenyl ring) as well as π–π stacking interactions involving the centroids (Cg1 and Cg2) of the N2/C13/N3/C7–C8 and N2/C9–C13 rings with a centroid-to-centroid distance Cg1⋯Cg2  of 3.5750 (9) Å and a slippage of 0.685 Å N-acetamide carbonoimidoyl]phenol °. In TUQCEP, C21H17N3O, the fused ring system is almost planar (r.m.s. deviation = 0.031 Å) and forms dihedral angles of 64.97 (7) and 18.52 (6)° with the phenyl ring and the (iminomethyl)phenol group, respectively. In its crystal, molecules are linked by pairs of C—H⋯π interactions into centrosymmetric dimeric units, which are further connected by O—H⋯N hydrogen bonds, forming layers parallel to (101).A search of the Cambridge Structural Database  to 1.2371 (blue) a.u. . The shape-index map of the title molecule was generated in the range −1 to 1 Å , revealing the presence of red and blue triangles that are indicative of the presence of π–π stacking interactions. The curvedness map of the title complex was generated in the range −4.0 to 4.0 Å  and shows flat surface patches characteristic of planar stacking. The Hirshfeld surface representations with the function dnorm plotted onto the surface are shown for the H⋯H, H⋯C/C⋯H, H⋯O/O⋯H, C⋯O/O⋯C, C⋯N/N⋯C, H⋯N/N⋯H and C⋯C interactions in Fig. 4a–g, respectively. The overall two-dimensional fingerprint plot is illustrated in Fig. 5a, with those delineated into H⋯H, H⋯C/C⋯H, H⋯O/O⋯H, C⋯O/O⋯C, C⋯N/N⋯C, H⋯N/N⋯H and C⋯C contacts associated with their relative contributions to the Hirshfeld surface in Fig. 5b–h, respectively. The most important intermolecular interaction is H⋯H, contributing 36.2% to the overall crystal packing . H⋯C/C⋯H contacts, with a 20.5% contribution to the Hirshfeld surface, indicate the presence of the weak C—H⋯π interaction . H⋯O/O⋯H contacts arising from intermolecular C—H⋯O hydrogen bonding make a 20.0% contribution to the Hirshfeld surface and are represented by a pair of sharp spikes in the region de + di ∼2.34 Å . The C⋯C contacts are a measure of π–π stacking interactions and contribute 4.3% of the Hirshfeld surface . The contributions of the other contacts to the Hirshfeld surface are C⋯O/O⋯C of 6.5%, C⋯N/N⋯C of 6.2% and H⋯N/N⋯H of 4.5%.Hirshfeld surface analysis was used to quantify the intermolecular contacts of the title compound, using u. Fig. 3a. The s Å Fig. 3b, revea Å Fig. 3c and shng Fig. 5b. H⋯C/Cn Table 1. Two paint Fig. 5c. H⋯O/O Å Fig. 5d. The Cce Fig. 5h. The ca]pyridine-8-carboxylate  in acetic acid (50 ml), sodium nitrite  was added at room temperature. The resulting precipitate was washed with water and extracted with dichloromethane (3 × 20 ml). The combined dichloromethane extracts were dried over anhydrous sodium sulfate and filtered. The remaining solution was concentrated under reduced pressure. The residue was purified chromatographically on a neutral alumina gel column using dichloromethane as eluent. Single crystals were obtained by slow evaporation of a dichloromethane solution at room temperature (yield 80%).To a solution of 2-oxo-2-phenylethyl 2-phenylimidazo, C—H = 0.93 Å for aromatic [Uiso(H) = 1.2Ueq(C)] and C—H = 0.98 Å for methine [Uiso(H) = 1.2Ueq(C)] H atoms.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989022001517/wm5632sup1.cifCrystal structure: contains datablock(s) I. DOI: 10.1107/S2056989022001517/wm5632Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989022001517/wm5632Isup3.cmlSupporting information file. DOI: 2106558CCDC reference:  crystallographicinformation; 3D view; checkCIF reportAdditional supporting information: