THE NATURE OF ALKALI CATION CONTACT ION-PAIRS WITH ANIONIC TRANSITION-METAL HYDRIDES HM(CO)4L-(M=CR, W - L = CO, PR3) Academic Article uri icon

abstract

  • Both infrared (v(CO) region) and 1H NMR results imply that in tetrahydrofuran solution the alkali cations Na+ and Li+ form contact ion pairs with cis-HM(CO)4PR3- (M = Cr, W; PR3 = P(OMe)3, PPh3, PMe3), specifically interacting at the hydride ligand or metal hydride bond density site. In contrast all the carbonyl hydrides HFe(CO)4-, CpV(CO)3H-, HW(CO)5-, and HCr(CO)5- show a preference for contact interaction at the CO oxygen site, although the more basic metal hydride HW(CO)5- displays some tendency for cation/tungsten hydride site interaction. The ion-pairing characteristics of the analogous anions CIW(CO)5- and cis-ClW(CO)4P(OMe)3- were compared to the hydrides. Contact ion pairs of Na+ or Li+ exclusively at the chloride site were detected by v(CO) IR spectral changes and preceded irreversible decomposition due to chloride ligand abstraction. A similar but slower alkali cation promoted decomposition of the 6B anionic hydrides was observed. The relationship between the ability of the anionic hydride carbonylates to serve as hydride donors and their tendency to interact with cations at the metal hydride site is noted. 1984, American Chemical Society. All rights reserved.

published proceedings

  • ORGANOMETALLICS

author list (cited authors)

  • KAO, S. C., DARENSBOURG, M. Y., & SCHENK, W.

citation count

  • 16

complete list of authors

  • KAO, SC||DARENSBOURG, MY||SCHENK, W

publication date

  • June 1984