Instituto de Física, Universidade Federal de Goiás, CP 131, 74001-970, Goiânia, Goiás, Brazil.
J Mol Model. 2013 Jan;19(1):329-36. doi: 10.1007/s00894-012-1551-8. Epub 2012 Aug 16.
Ab initio calculations were employed to study the role of ipso carbon hybridization in halogenated compounds RX (R=methyl, phenyl, acetyl, H and X=F, Cl, Br and I) and its interaction with a phosphorus atom, as occurs in the halogen bonded complex type RX⋯PH3. The analysis was performed using ab initio MP2, MP4 and CCSD(T) methods. Systematic energy analysis found that the interaction energies are in the range -4.14 to -11.92 kJ mol(-1) (at MP2 level without ZPE correction). Effects of electronic correlation levels were evaluated at MP4 and CCSD(T) levels and a reduction of up to 27% in interaction energy obtained in MP2 was observed. Analysis of the electrostatic maps confirms that the PhCl⋯PH3 and all MeX⋯PH3 complexes are unstable. NBO analysis suggested that the charge transfer between the moieties is bigger when using iodine than bromine and chlorine. The electrical properties of these complexes (dipole and polarizability) were determined and the most important observed aspect was the systematic increase at the dipole polarizability, given by the interaction polarizability. This increase is in the range of 0.7-6.7 u.a. (about 3-7%).
采用从头算方法研究了 ipso 碳杂化在卤代化合物 RX（R=甲基、苯基、乙酰基、H 和 X=F、Cl、Br 和 I）中的作用及其与磷原子的相互作用，如在卤键复合物类型 RX⋯PH3 中发生的相互作用。分析使用从头算 MP2、MP4 和 CCSD(T)方法进行。系统能量分析发现，相互作用能在-4.14 到-11.92 kJ mol(-1)范围内（在没有 ZPE 校正的 MP2 水平下）。在 MP4 和 CCSD(T)水平上评估了电子相关能级的影响，在 MP2 中观察到相互作用能降低了高达 27%。静电映射分析证实 PhCl⋯PH3 和所有 MeX⋯PH3 复合物都是不稳定的。NBO 分析表明，当使用碘时，部分之间的电荷转移比溴和氯大。这些复合物的电学性质（偶极矩和极化率）已被确定，观察到的最重要方面是由相互作用极化率引起的偶极极化率的系统增加。这种增加在 0.7-6.7 u.a.（约 3-7%）范围内。
