Department of Chemistry, Xavier University of Louisiana, New Orleans, LA 17025, USA.
J Mol Model. 2013 Jul;19(7):2879-83. doi: 10.1007/s00894-012-1727-2. Epub 2013 Jan 8.
O-H...X and O-H...O H-bonds as well as C-X...X dihalogen and C-X...O halogen bonds have been investigated in halomethanol dimers (bromomethanol dimer, iodomethanol dimer, difluorobromomethanol…bromomethanol complex and difluoroiodomethanol…iodomethanol complex). Structures of all complexes were optimized at the counterpoise-corrected MP2/cc-pVTZ level and single-point energies were calculated at the CCSD(T)/aug-cc-pVTZ level. Energy decomposition for the bromomethanol dimer complex was performed using the DFT-SAPT method based on the aug-cc-pVTZ basis set. OH...O and OH...X H-bonds are systematically the strongest in all complexes investigated, with the former being the strongest bond. Halogen and dihalogen bonds, being of comparable strength, are weaker than both H-bonds but are still significant. The strongest bonds were found in the difluoroiodomethanol…iodomethanol complex, where the O-H...O H-bond exceeds 7 kcal mol(-1), and the halogen and dihalogen bonds exceed 2.5 and 2.3 kcal mol(-1), respectively. Electrostatic energy is dominant for H-bonded structures, in halogen bonded structures electrostatic and dispersion energies are comparable, and, finally, for dihalogen structures the dispersion energy is clearly dominant.
O-H…X 和 O-H…O 氢键以及 C-X…X 二卤键和 C-X…O 卤键已在卤代甲醇二聚体（溴代甲醇二聚体、碘代甲醇二聚体、二氟溴代甲醇…溴代甲醇复合物和二氟碘代甲醇…碘代甲醇复合物）中进行了研究。所有复合物的结构均在平衡校正 MP2/cc-pVTZ 水平上进行了优化，并在 CCSD(T)/aug-cc-pVTZ 水平上计算了单点能。使用基于 aug-cc-pVTZ 基组的 DFT-SAPT 方法对溴代甲醇二聚体复合物进行了能量分解。在所有研究的复合物中，OH…O 和 OH…X 氢键系统地是最强的，前者是最强的键。卤键和二卤键具有相当的强度，比氢键弱，但仍然很重要。在最强的键中发现了二氟碘代甲醇…碘代甲醇复合物，其中 O-H…O 氢键超过 7 kcal mol(-1)，卤键和二卤键分别超过 2.5 和 2.3 kcal mol(-1)。静电能对氢键结构占主导地位，在卤键结构中静电能和色散能相当，最后，在二卤键结构中色散能明显占主导地位。
