Padgett Clifford W, Dean Riley, Cobb Audrey, Miller Aubree, Goetz Andrew, Bailey Sam, Hillis Kyle, McMillen Colin, Toney Sydney, Guillet Gary L, Lynch Will, Pennington William T
Department of Biochemistry, Chemistry and Physics, Georgia Southern University, Savannah, Georgia 31419, United States.
Department of Chemistry, Clemson University, Clemson, South Carolina 29634-0973, United States.
Cryst Growth Des. 2024 Mar 5;24(6):2425-2438. doi: 10.1021/acs.cgd.3c01344. eCollection 2024 Mar 20.
A series of cocrystals of halogen bond donors 1,4-diiodotetrafluorobenzene (-FDIB) and tetraiodoethylene (TIE) with five aromatic heterocyclic diazine mono--oxides based on pyrazine, tetramethylpyrazine, quinoxaline, phenazine, and pyrimidine as halogen bonding acceptors were studied. Structural analysis of the mono--oxides allows comparison of the competitive occurrence of N···I vs O···I interactions and the relative strength and directionality of these two types of interactions. Of the aromatic heterocyclic diazine mono--oxide organoiodine cocrystals examined, six exhibited 1:1 stoichiometry, forming chains that utilized both N···I and O···I interactions. Two cocrystals presented 1:1 stoichiometry with exclusive O···I interactions. Two cocrystals displayed a 2:1 stoichiometry-one characterized solely by O···I interactions and the other solely by N···I interactions. We have also compared these interactions to those present in the corresponding diazines, some of which we report here and some which have been previously reported. In addition, a computational analysis using density functional theory (M062X/def2-SVPD) was performed on these two systems and has been compared to the experimental results. The calculated complex formation energies were, on average, 4.7 kJ/mol lower for the I···O halogen bonding interaction as compared to the corresponding N···I interaction. The average I···O interaction distances were calculated to be 0.15 Å shorter than the corresponding I···N interactions.
研究了一系列基于吡嗪、四甲基吡嗪、喹喔啉、吩嗪和嘧啶的五个芳香族杂环二嗪单氧化物作为卤素键受体与卤素键供体1,4 - 二碘四氟苯（-FDIB）和四碘乙烯（TIE）形成的共晶体。对单氧化物的结构分析允许比较N···I与O···I相互作用的竞争出现情况以及这两种相互作用的相对强度和方向性。在所研究的芳香族杂环二嗪单氧化物有机碘共晶体中，六个呈现1:1化学计量比，形成利用N···I和O···I两种相互作用的链。两个共晶体呈现1:1化学计量比且仅具有O···I相互作用。两个共晶体呈现2:1化学计量比——一个仅由O···I相互作用表征，另一个仅由N···I相互作用表征。我们还将这些相互作用与相应二嗪中存在的相互作用进行了比较，其中一些我们在此报告，一些此前已被报道。此外，对这两个体系进行了使用密度泛函理论（M062X/def2 - SVPD）的计算分析，并与实验结果进行了比较。计算得到的I···O卤素键相互作用的复合物形成能平均比相应的N···I相互作用低4.7 kJ/mol。计算得到的平均I···O相互作用距离比相应的I···N相互作用短0.15 Å。
