Molecular Orbital Calculations on Transition-Metal Complexes. 22.' Bis

Bis(borabenzene) Compounds of the 3d Series

Inorganic Chemistry, Vol. 18, No. 2, 1979 513 Contribution from the Department of Chemistry, University College, Cardiff C F l l X L , Wales, United Kingdom

Molecular Orbital Calculations on Transition-Metal Complexes. 22.' Bis(borabenzene) Compounds of the 3d Series D E N I S W . CLACK* and KEITH D. WARREN*

Received April 27, 1978 INDO-SCF molecular orbital calculations have been carried out for the bis(borabenzene) M(C5H5BR)2( R = H , M = Cr, Mn, Fe, Co; R = CH3, M = Fe, Co) complexes of the 3d series. The major contribution to the d-orbital splitting is found to arise from the interaction between the ligand x orbitals and the metal el(d,,dy,) orbitals, which become strongly antibonding, but the ligand u orbitals play a significant role in the bonding and are substantially mixed with the metal e2(dX2-g,dxy)and al(d,2) levels. The ordering of the mainly metal 3d levels corresponds to the one-electron energy sequence d,+g d, < dZ2