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Acta Crystallogr C Struct Chem. 2022 Dec 1;78(Pt 12):716-721. doi: 10.1107/S205322962201052X. Epub 2022 Nov 9.
The amino group of 2-amino-5-(4-halophenyl)-1,3,4-chalcogenadiazole has been replaced with bromo/iodo substituents to obtain a library of four compositionally related compounds. These are 2-iodo-5-(4-iodophenyl)-1,3,4-thiadiazole, CHINS, 2-bromo-5-(4-bromophenyl)-1,3,4-selenadiazole, CHBrNSe, 2-bromo-5-(4-iodophenyl)-1,3,4-selenadiazole, CHBrINSe, and 2-bromo-5-(4-iodophenyl)-1,3,4-thiadiazole, CHBrINS. All were isostructural and contained bifurcated Ch...N (Ch is chalcogen) and X...X (X is halogen) interactions forming a zigzag packing motif. The noncovalent Ch...N interaction between the chalcogen-bond donor and the best-acceptor N atom appeared preferentially instead of a possible halogen bond to the same N atom. Hirshfeld surface analysis and energy framework calculations showed that, collectively, a bifurcated chalcogen bond was stronger than halogen bonding and this is more structurally influential in this system.
2-氨基-5-(4-卤代苯基)-1,3,4-噻二唑的氨基被溴/碘取代，得到了一组四个组成相关的化合物。这些化合物分别为 2-碘-5-(4-碘苯基)-1,3,4-噻二唑、CHINS、2-溴-5-(4-溴苯基)-1,3,4-硒二唑、CHBrNSe、2-溴-5-(4-碘苯基)-1,3,4-硒二唑、CHBrINSe 和 2-溴-5-(4-碘苯基)-1,3,4-噻二唑、CHBrINS。它们都是同构的，含有分叉的 Ch...N（Ch 是杂原子）和 X...X（X 是卤素）相互作用，形成了一个锯齿形的堆积模式。卤键供体和最佳受体 N 原子之间的非共价 Ch...N 相互作用优先于可能与同一 N 原子形成的卤键。Hirshfeld 表面分析和能量框架计算表明，分叉的杂原子键比卤键更强，在这个体系中具有更强的结构影响力。
