CLOSED-SHELL ELECTRONIC-STRUCTURES FOR LINEAR LNMXMLN DINUCLEAR TRANSITION-METAL COMPLEXES

The unparametrized Fenske-Hall method is used to study the closed-shell electronic requirements for a large number of linear L(n)MXML(n) (n = 3-6) dinuclear transition-metal complexes. The linearity of the dinuclear complexes relates closely to the two 3-center pi bonds in the M-X-M unit. The occupation of the corresponding pi-antibonding orbitals results in a severely bent M-X-M geometry. Linear dinuclear complexes with vertex-sharing tetrahedra, L3MXML3, require a d8-d8 closed-shell configuration. For linear L5MXML5 complexes with a structure of vertex-sharing octahedra, a d4-d4 configuration will satisfy the closed-shell requirement. Complexes L6MXML6 with a linear vertex-sharing pentagonal-bipyramidal geometry correspond to a d2-d2 closed-shell configuration.