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.

Key words: SEMICONDUCTOR MATERIAL, CNDO APPROXIMATION, HIGHPOLYMER, STRUCTURE AND PROPERTY CORRELATION, ELECTRONIC STRUCTURE, TRANSITION METAL COMPOUND, FIVE MEMBER RING HETEROCYCLIC COMPOUNDS, SELF-CONSISTENT FIELD, BORON HETEROCYCLIC COMPOUNDS, SANDWICH COMPOUNDS