Yan Jiajing, Zeng Yanli, Meng Lingpeng, Li Xiaoyan, Zhang Xueying
College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, P. R. China.
Hebei Key Laboratory of Inorganic Nano-materials, Hebei Normal University, Shijiazhuang, 050024, P. R. China.
Phys Chem Chem Phys. 2023 Nov 1;25(42):29155-29164. doi: 10.1039/d3cp04354a.
Except for the well-known σ-hole regium bonds formed by metal nanoparticles and M(I) (M = Cu, Ag, and Au) derivatives, the existence of π-hole regions located above and below the Au atom in gold(III) derivatives suggests that gold(III) also functions as an efficient electrophilic site. In this study, a comprehensive analysis was conducted on the electrophilicity of trichloro-(-toluonitrilo-N)-gold(III) derivatives AuL(NCCHX) (L = Cl, Br, CN; X = NH, CH, CF, NC, and CN) and the nature of π-hole regium bonds in the AuL(NCCHX)⋯LB (LB = NH, N(NH), CHO, CH, CH, CH) and (AuCl(NCCHY)) (Y = Cl, CN, NC, NO; = 2, 3)) complexes. The characteristics of the π-hole regium bonds were studied with respect to the influence of ligands and substituents, the strength of intermolecular interactions between Au(III) derivatives and Lewis bases, and those in the polymers. In the case of the AuL(NCCHX)⋯NH complexes, the strength of the regium bonds increases gradually in the order of L = Cl < Br < CN and X = NH < CH < CF ≈ NC < CN. The ligands (L) attached to the Au atom exert a significant effect on the strength of the π-hole regium bonds in comparison to the substituents (X) on the benzene ring. The regium bonds are primarily dominated by electrostatic interaction, accompanied by moderate contribution from polarization. Linear relationships were identified between the electrostatic energies and the local most positive potentials over the Au atom, as well as between the polarization energies and the amount of charge transfer. Most of the π-hole regium bonds in the AuL(NCCHX)⋯LB complexes exhibit the characters of closed shell noncovalent interactions. In the polymers (AuCl(NCCHY)), weak face-to-face π-π stacking interactions are also present, in addition to regium bonds. The trimers displayed a slightly negative cooperativity in comparison to the dimers.
除了由金属纳米颗粒和M(I)（M = Cu、Ag和Au）衍生物形成的众所周知的σ-空穴区域键外，金(III)衍生物中位于金原子上方和下方的π-空穴区域的存在表明金(III)也作为一个有效的亲电位点发挥作用。在本研究中，对三氯-(-甲苯腈基-N)-金(III)衍生物AuL(NCCHX)（L = Cl、Br、CN；X = NH、CH、CF、NC和CN）的亲电性以及AuL(NCCHX)⋯LB（LB = NH、N(NH)、CHO、CH、CH、CH）和(AuCl(NCCHY))（Y = Cl、CN、NC、NO； = 2, 3）配合物中π-空穴区域键的性质进行了全面分析。研究了π-空穴区域键的特征，涉及配体和取代基的影响、金(III)衍生物与路易斯碱之间分子间相互作用的强度以及聚合物中的相互作用。在AuL(NCCHX)⋯NH配合物的情况下，区域键的强度按L = Cl < Br < CN和X = NH < CH < CF ≈ NC < CN的顺序逐渐增加。与苯环上的取代基(X)相比，连接到金原子上的配体(L)对π-空穴区域键的强度有显著影响。区域键主要由静电相互作用主导，同时伴有适度的极化贡献。确定了静电能与金原子上的局部最正电位之间以及极化能与电荷转移量之间的线性关系。AuL(NCCHX)⋯LB配合物中的大多数π-空穴区域键表现出闭壳层非共价相互作用的特征。在聚合物(AuCl(NCCHY))中，除了区域键外，还存在弱的面对面π-π堆积相互作用。与二聚体相比，三聚体表现出略微负的协同性。
