Tsuzuki Seiji, Uchimaru Tadafumi, Wakisaka Akihiro, Ono Taizo
Research Center for Computational Design of Advanced Functional Materials, National Institute of Advanced Industrial Science and Technology , 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology , 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
J Phys Chem A. 2016 Sep 8;120(35):7020-9. doi: 10.1021/acs.jpca.6b06295. Epub 2016 Aug 24.
Geometries of benzene complexes with C6F5X, C6H5X, and CF3X (X is I, Br, Cl, and F) were optimized, and their interaction energies were evaluated. The CCSD(T) interaction energies at the basis set limit (Eint) of C6F5X (X is I, Br, Cl, and F) with benzene were -3.24, -2.88, -2.31, and -0.92 kcal mol(-1). Eint of C6H5X (X is I, Br, and Cl) with benzene were -2.31, -1.97, and -1.48 kcal mol(-1). The fluorination of halobenzenes slightly enhances the attraction. Eint of CF3X (X is I, Br, Cl, and F) with benzene (-3.11, -2.74, -2.22, and -0.71 kcal mol(-1)) were very close to Eint of corresponding C6F5X with benzene. In contrast to the halogen bond of iodine and bromine with pyridine (n-type halogen bond acceptor) where the main cause of the attraction is the electrostatic interactions, that of halogen bond with benzene (p-type acceptor) is dispersion interaction. In the halogen bonds with p-type acceptors (halogen-π interactions), the electrostatic interactions and induction interactions are small. The overall orbital-orbital interactions are repulsive. The directionality of halogen bonds with p-type acceptors is very weak, owing to the weak electrostatic interactions, in contrast to the strong directionality of the halogen bonds with n-type acceptors and hydrogen bonds.
对苯与C6F5X、C6H5X和CF3X（X为I、Br、Cl和F）形成的配合物的几何结构进行了优化，并评估了它们的相互作用能。在基组极限下，C6F5X（X为I、Br、Cl和F）与苯的CCSD(T)相互作用能（Eint）分别为-3.24、-2.88、-2.31和-0.92 kcal mol(-1)。C6H5X（X为I、Br和Cl）与苯的Eint分别为-2.31、-1.97和-1.48 kcal mol(-1)。卤代苯的氟化略微增强了吸引力。CF3X（X为I、Br、Cl和F）与苯的Eint（-3.11、-2.74、-2.22和-0.71 kcal mol(-1)）与相应的C6F5X与苯的Eint非常接近。与碘和溴与吡啶（n型卤素键受体）形成的卤素键不同，后者吸引力的主要原因是静电相互作用，而卤素与苯（p型受体）形成的卤素键是色散相互作用。在与p型受体形成的卤素键（卤素-π相互作用）中，静电相互作用和诱导相互作用较小。整体的轨道-轨道相互作用是排斥的。与n型受体形成的卤素键和氢键的强方向性相反，由于静电相互作用较弱，与p型受体形成的卤素键的方向性非常弱。
