EDGE-BRIDGED TETRAHEDRAL GEOMETRY OF 5-COORDINATE D(0) COMPLEXES, RELATIVES OF THE BENT [MCP2L3] FAMILY - A THEORETICAL AND STRUCTURE-CORRELATION STUDY

The edge-bridged tetrahedral geometry of five-coordinate d(0) complexe s [MD2L3] with strong pi-donors D is analyzed with extended Huckel met hodology as well as density functional theory. It is shown that this g eometry, also encountered in bent metallocene systems [MCp2L3], can be considered as a distortion of a regular trigonal bipyramid arising fr om a second-order Jahn-Teller distortion of e' symmetry (in D-3h) and corresponds to a deformation along a reversed-Ferry pathway. This mode l was tested with a structure-correlation analysis of all experimental ly determined [MD2L3] structures, thus allowing a mapping of the rever sed-Berry pathway. The catalytic potential of these complexes and thei r isolobal relationship to [MCp2L3] are emphasized.