单硼五元杂环配体(C~4BH~5)过渡金属夹心高聚物的理论研究

用一维自洽场晶体轨道法探讨了过渡金属夹心高聚物(C~4BH~5)M]~n(M=Cr,Mn,Fe,Co,Ni)的一维链结构和电子结构.计算表明,堆积单元(C~4BH~5)M中价电子数为奇数的高聚物结构会发生Peierls畸变,而价电子数为偶数的将取规则结构,由能带结构得到, (C~4BH~5)Mn]~n的前线能带出现交叉,可能会发生进一步的结构畸变,但也有可能保持非满状态,成为异体.(C~4BH~5)Ni]~n可能是不稳定的.其余三个高聚物为半导体或绝缘体,这系列高聚物电荷载流子通路主要依赖于金属d轨道重叠.

Theortical studies on transition metal polydecker sandwich compounds with ligand C~4BH~5

The chain and electronic structure of the polydecker sandwich compounds (C4BH4)M]n (M = Cr, Mn, Fe, Co, Ni) have been theor. studied by using one-dimensional SCF-CO (SCF-crystal orbital) method. The calculated results indicate that the polymers with odd valence electrons in each stacking unit (C4BH5)M have a Peierls distortion structure. The frontier bands of (C4BH5)Mn] cross; hence, it is expected to be a conductor or it may be further distored. (C4BH5)Ni]n is unstable. The other three polymers are either a semiconductor or an insulator. And, the paths of charge carriers are mainly depend on the overlaps of d orbitals between metal atoms.