一类新型含平面四配位碳、硅和锗的化合物的结构与成键性质  

Structures and bonding properties of one new type of compound with the planar tetracoordinate carbon,silicon and germanium

作　　者：张彩云 方磊 张于微 曹泽星 ZHANG Caiyun;FANG Lei;ZHANG Yuwei;CAO Zexing(Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学化学化工学院,福建省理论与计算化学重点实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2021年第5期821-827,共7页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(21873078,21673185)。

摘　　要：采用密度泛函理论方法,研究了一类新型含平面四配位碳、硅和锗的化合物的结构、成键、稳定性和光谱性质.通过结构优化和振动分析表明,这类含有平面四配位结构单元CB_(4)、SiN_(4)、GeN_(4)、GeB_(4)的分子具有稳定的电子和几何结构.这些稳定体系均存在中心原子与周围4个原子间的共轭π键,其中中心原子C为π电子给体,Si为π电子受体,而Ge可以是π电子受体也可以是给体.对于含平面四配位硅和锗的分子C_(20)H_(16)N_(4)Si和C_(20)H_(16)N_(4)Ge,中心原子采取sp^(2)d杂化方式与周围的N原子形成σ键,而由于C原子价层无d轨道且s和p轨道的能级差相对较小,近似采用sp^(2)杂化与周围的B原子形成多中心σ键.Extensive density functional theory calculations have been used to explore structures,bonding features,stabilities and spectroscopic properties of a new type of compound with the planar tetracoordinate carbon(ptC),ptSi,and ptGe.These compounds with the planar CB_(4),SiN_(4),GeN_(4),and GeB_(4) moieties are predicted to be stable,both structurally and electronically,according to the structure optimizations and frequency analysis.There is generally a delocalizedπbond between the central atom and its surrounding four atoms in such stable planar tetracoordinate compounds,in which the central atom C and Si behave as theπdonor and acceptor,respectively,while Ge bears the characteristics of bothπdonor and acceptor.In the compounds of C_(20)H_(16)N_(4)X(X=Si and Ge),the central atom Si and Ge adopt sp^(2)d hybridization to formσbonds with surrounding N atoms.Since there is relatively small s-p energy splitting for C atom without the d orbital,an approximate sp^(2) hybridization is responsible for itsσbonding with surrounding B atoms.

关 键 词：平面四配位化合物 密度泛函理论计算 化学键 电子光谱 

分 类 号：O641.2[理学—物理化学]