Mirchi Ali, Sizochenko Natalia, Dinadayalane Tandabany, Leszczynski Jerzy
Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University , 1400 J. R. Lynch Street, Jackson, Mississippi 39217, United States.
Department of Chemistry, Clark Atlanta University , 223 James P. Brawley Drive, S.W., Atlanta, Georgia 30314, United States.
J Phys Chem A. 2017 Nov 22;121(46):8927-8938. doi: 10.1021/acs.jpca.7b08725. Epub 2017 Nov 8.
The effect of substitution of phenyl and naphthyl rings to benzene was examined to elucidate the cation-π interactions involving alkali metal ions with 1,3,5-tri(phenyl)benzene (TPB) and 1,3,5-tri(naphthyl)benzene (TNB). Benzene, TPB, and four TNB isomers (with ααα, ααβ, αββ, and βββ types of fusion) and their complexes with Li, Na, K, Rb, and Cs were optimized using DFT approach with B3LYP and M06-2X functionals in conjunction with the def2-QZVP basis set. Higher relative stability of β,β,β-TNB over α,α,α-TNB can be attributed to peri repulsion, which is defined as the nonbonding repulsive interaction between substituents in the 1- and the 8-positions on the naphthalene core. Binding energies, distances between ring centroid and the metal ions, and the distance to metal ions from the center of other six-membered rings were compared for all complexes. Our computational study reveals that the binding affinity of alkali metal cations increases significantly with the 1,3,5-trisubstitution of phenyl and naphthyl rings to benzene. The detailed computational analyses of geometries, partial charges, binding energies, and ligand organization energies reveal the possibility of favorable C-H···M interactions when a α-naphthyl group exists in complexes of TNB structures. Like benzene-alkali metal ion complexes, the binding affinity of metal ions follows the order: Li > Na > K > Rb > Cs for any considered 1,3,5-trisubstituted benzene systems. In case of TNB, we found that the strength of interactions increases as the fusion point changes from α to β position of naphthalene.
研究了用苯基和萘基环取代苯环的效果，以阐明碱金属离子与1,3,5-三（苯基）苯（TPB）和1,3,5-三（萘基）苯（TNB）之间的阳离子-π相互作用。使用DFT方法，结合B3LYP和M06-2X泛函以及def2-QZVP基组，对苯、TPB、四种TNB异构体（具有ααα、ααβ、αββ和βββ型稠合）及其与Li、Na、K、Rb和Cs的配合物进行了优化。β,β,β-TNB相对于α,α,α-TNB具有更高的相对稳定性，这可归因于邻位排斥，邻位排斥定义为萘核上1位和8位取代基之间的非键排斥相互作用。比较了所有配合物的结合能、环质心与金属离子之间的距离以及从其他六元环中心到金属离子的距离。我们的计算研究表明，碱金属阳离子的结合亲和力随着苯基和萘基环对苯的1,3,5-三取代而显著增加。对几何结构、部分电荷、结合能和配体组织能的详细计算分析表明，当TNB结构的配合物中存在α-萘基时，存在有利的C-H···M相互作用的可能性。与苯-碱金属离子配合物一样，对于任何考虑的1,3,5-三取代苯体系，金属离子的结合亲和力顺序为：Li > Na > K > Rb > Cs。对于TNB，我们发现，随着稠合点从萘的α位变为β位，相互作用的强度增加。
