Transition Metal Polyhydride Complexes. 7. Classical and Nonclassical Structures of [ReH4(CO)(PR3)3]+ Academic Article uri icon

abstract

  • The stabilities of different structures for [ReH4(CO)(PH3)3]+ are predicted from ab initio calculations at the MP2 level with effective core potential, split-valence basis sets. Two structures have been found to be of almost equal energy. One has a dodecahedral geometry (1) with the four hydride ligands occupying the B sites, and the other has a pentagonal-bipyramidal geometry (2) with one η2-H2 ligand. These two structures represent the clssical and nonclassical tautomers observed experimentally in a solution of [ReH4(CO)(PMe2Ph)3] [BF4]. The hydride-hydrogen site exchange in the nonclassical structure (2) and the interconversion process between 1 and 2 have also been studied. The interconversion was found to be faster (calc barrier 4 kcal/mol) than the site exchange process (calc barrier >8 kcal/mol). From these calculations, we proposed a new interpretation of the NM R experiments. The different chemistry observed for [ReH4(PMe2Ph)4]+ is explained by the interaction of metal d orbitals with the CO π* obitals. © 1994, American Chemical Society. All rights reserved.

published proceedings

  • Journal of the American Chemical Society

author list (cited authors)

  • Lin, Z., & Hall, M. B

citation count

  • 17

complete list of authors

  • Lin, Zhenyang||Hall, Michael B

publication date

  • May 1994