Nonparameterized MO calculations of ligand-bridged M2(CO)8-(U2-X)2-type dimers containing metalmetal interactions: Evidence for dictation of stereochemistry by one-electron and two-electron metalmetal σ-type bonds Academic Article uri icon


  • Nonparameterized MO calculations performed on the (edge-bridged)-bioctahedral metal dimers of the Dessy-characterized [Cr2(CO)8(μ2-PR2) 2](n-2) series and of the [Mn2(CO)8(μ2-PR2) 2]n series (n = 0, +1, +2) have revealed that the corresponding dimeric pairs with n = 0, +1, and +2 have two, one, and no electrons, respectively, in the antibonding 2b3u MO corresponding to a "net" no-electron metalmetal bond, a "net" one-electron metalmetal bond, and a two electron metalmetal bond. Of prime significance is that this 2b3u MO, which is the LUMO in both electron-pair (metalmetal)-bonded dimers (n = +2) and the HOMO in the corresponding dimers to which one or two electrons have been added, is found to be largely composed of in-plane antibonding σ{black star}-type dimetal orbital character rather than either out-of-plane π{black star}-type dimetal antibonding orbital character or bridging-ligand orbital character. These MO results are also shown to be completely compatible with the available spectral and X-ray data. © 1974.

author list (cited authors)

  • Teo, B. K., Hall, M. B., Fenske, R. F., & Dahl, L. F.

citation count

  • 58

publication date

  • May 1974