Metal cluster chemistry: Structure and stereochemistry in the polynuclear rhodium hydrides H_nRh_n[P(OR)₃]_2n

Authors

R. K. Brown, Argonne National Laboratory
J. M. Williams, Argonne National Laboratory
M. F. Fredrich, University of Nebraska - Lincoln
V. W. Day, University of Nebraska - Lincoln
A. J. Sivak, University of California - Berkeley
E. L. Muetterties, University of California - Berkeley

Date of this Version

1979

Comments

Published in Proc. Natl. Acad. Sci. USA Vol. 76, No. 5, pp. 2099-2102, May 1979. Used by Permission

Abstract

Crystallographic analyses of x-ray and neutron diffraction data have provided a definitive structural representation of {HRh[P(O-i-C₃H₇)₃]₂}₂ and [HRh[P(OCH₃)₃]₂}₃. These polynuclear hydrides are generated from square planar H2Rh[P(OR)₃]₂ units by edge (hydrogen atom) sharing and by vertex (hydrogen atom) sharing to form the dimeric and trimeric structures, respectively. The square-planar units are held together through four-center and three-center two-electron Rh-H-Rh bonds in the dimer and trimer, respectively. The dimer and trimer molecules each add one molecule of hydrogen to form H[(i-C₃H₇O)₃P]₂RhH₃Rh[P(O-i-C₃H₇)₃]₂ and H₅Rh₃[P(OCH₃)₃]₆, respectively. NMR spectral information has served to define the stereochemical features of these polyhydrides. The significance of this chemistry in the metal clustermetal surface analogy is described.