1,3-Diiodotetrafluorobenzene and 1,3,5-trifluoro-2,4,6-triiodobenzene form co-crystals with 4,4â²,6,6â²-tetramethyl-2,2â²-bipyrimidine, 1,2,4,5-tetra(3-pyridyl)benzene and 1,2,4,5-tetra(4-pyridyl)benzene in which the structural competition between Ïâ¯Ï interactions and halogen bonds is directly observed. It is found that the strong CâIâ¯N halogen bond competes successfully with the Ïâ¯Ï interaction between two 1,3-diiodotetrafluorobenzene molecules while the Ïâ¯Ï interaction between two 1,3,5-trifluoro-2,4,6-triiodobenzene molecules can successfully compete with the strong CâIâ¯N halogen bond. Quantum chemical calculations explain the structural competition well.
1,3-二碘四氟苯和 1,3,5-三
氟-2,4,6-三
碘苯与 4,4â²,6,6â²-四甲基-2,2â²-联
嘧啶、1,2,4,5-四(3-
吡啶基)苯和 1,2,4,5-四(4-
吡啶基)苯形成共晶体,其中直接观察到Ïâ¯Ï相互作用和卤素键之间的结构竞争。研究发现,强 CâIâ¯N 卤素键能成功地与两个 1,3 二
碘四氟苯分子之间的Ïâ¯Ï相互作用竞争,而两个 1,3,5 三
氟-2,4,6-三
碘苯分子之间的Ïâ¯Ï相互作用能成功地与强 CâIâ¯N 卤素键竞争。量子
化学计算很好地解释了这种结构竞争。