Ibrahim Mahmoud A A, Saad Sherif M A, Al-Fahemi Jabir H, Mekhemer Gamal A H, Ahmed Saleh A, Shawky Ahmed M, Moussa Nayra A M
Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University Minia 61519 Egypt
Chemistry Department, Faculty of Applied Sciences, Umm Al-Qura University Makkah 21955 Saudi Arabia.
RSC Adv. 2021 Jan 19;11(7):4022-4034. doi: 10.1039/d0ra09765a.
σ-hole and lone-pair (lp) hole interactions of trivalent pnicogen-bearing (ZF) compounds were comparatively scrutinized, for the first time, under field-free and external electric field (EEF) conditions. Conspicuously, the sizes of the σ-hole and lp-hole were increased by applying an EEF along the positive direction, while the sizes of both holes decreased through the reverse EEF direction. The MP2 energetic calculations of ZF⋯FH/NCH complexes revealed that σ-holes exhibited more impressive interaction energies compared to the lp-holes. Remarkably, the strengths of σ-hole and lp-hole interactions evolved with the increment of the positive value of the considered EEF; , the interaction energy increased as the utilized EEF value increased. Unexpectedly, under field-free conditions, nitrogen-bearing complexes showed superior strength for their lp-hole interactions than phosphorus-bearing complexes. However, the reverse picture was exhibited for the interaction energies of nitrogen- and phosphorus-bearing complexes interacting within lp-holes by applying the high values of a positively directed EEF. These results significantly demonstrate the crucial influence of EEF on the strength of σ-hole and lp-hole interactions, which in turn leads to an omnipresent enhancement for variable fields, including biological simulations and material science.
首次在无外场和外加电场（EEF）条件下，对含三价氮族元素的（ZF）化合物的σ-空穴和孤对（lp）空穴相互作用进行了比较研究。值得注意的是，沿正方向施加EEF会增大σ-空穴和lp-空穴的尺寸，而通过反向EEF方向则会减小两个空穴的尺寸。ZF⋯FH/NCH配合物的MP2能量计算表明，与lp-空穴相比，σ-空穴表现出更显著的相互作用能。值得注意的是，σ-空穴和lp-空穴相互作用的强度随着所考虑的EEF正值的增加而变化；也就是说，相互作用能随着所使用的EEF值的增加而增加。出乎意料的是，在无外场条件下，含氮配合物的lp-空穴相互作用强度比含磷配合物更强。然而，通过施加高值的正向EEF，含氮和含磷配合物在lp-空穴内相互作用的能量呈现出相反的情况。这些结果显著证明了EEF对σ-空穴和lp-空穴相互作用强度的关键影响，这反过来又导致了包括生物模拟和材料科学在内的可变场的普遍增强。
