THEORETICAL-STUDIES ON TRANSITION-METAL POLYDECKER SANDWICH COMPOUNDS WITH LIGAND C4BH5

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