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采用B3LYP/6-311+G**方法,我们优化了初始构型中包含两个平面五配位碳原子(ppCs)的C2+nB10-n(n=0～10)团簇的结构并计算了它们的振动频率.计算结果表明,C2+nB10-n(n=0～2)团簇是稳定的,而且这三个结构中ppC—B键的Wiberg键级介于0.511～0.909之间,ppC—C键的Wiberg键级为0.2254(n=1)和0.8586(n=2),ppC的键级介于3.778到3.879之间,即这三个结构中存在两个ppCs,而且ppC遵循八隅规则;C2+nB10-n(n=3～6)团簇的最稳定结构包含一个ppC;C2+nB10-n(n>6)团簇能量最低结构中不存在ppC.而且只有团簇C2+nB10-n(n=0～2)中没有悬键,它们的π电子数分别为:6,7和8,计算它们的NICS(0)值表明强芳香性一般位于局部的三元环中心,表明局部离域有利于平面结构的形成.C2+nB10-n(n=0～2)团簇的第一垂直激发能分别为:1.91,0.56和3.12eV.
Using the B3LYP / 6-311 + G ** method, we optimized the structure of C2 + nB10-n (n = 0 ~ 10) clusters containing two planar pentacoordinated carbon atoms (ppCs) in the initial configuration and calculated (N = 0 ~ 2) clusters are stable, and the Wiberg bond order of the ppC-B bonds in these three structures is between 0.511 ~ 0.909, The ppC-C bonds have a Wiberg bond order of 0.2254 (n = 1) and 0.8586 (n = 2) with a ppC bond order of 3.778 to 3.879, ie, two ppCs are present in these three constructs and the ppC follows eight The most stable structure of C2 + nB10-n (n = 3-6) clusters contains one ppC; there is no ppC in the lowest energy structure of C2 + nB10-n (n> 6) clusters and only cluster C2 + nB10-n (n = 0 ~ 2) have no dangling bonds and their π electrons are 6, 7 and 8, respectively. Calculating their NICS (0) values indicates that strong aromaticity is generally localized at the local three-membered ring center , Indicating that local delocalization favors the formation of planar structures.The first vertical excitation energies of C2 + nB10-n (n = 0 ~ 2) clusters are 1.91, 0.56 and 3.12eV, respectively.