The synthesis, x-ray crystal structure, and solution characterization of a bis(diphosphine)-bridged dirhodium(I) complex containing a Rh2P4 six-membered ring


Journal Article

The preparation of [{Rh(cod)}2(μ-L1)2][BF4] 2 (1) from (CH2CMe=CH2P)2 (L1) and [Rh(cod)2]-BF4 (cod = cyclo-octa-1,5-diene) is described. The compound crystallizes in the monoclinic space group P21/c (C52h), with a = 9.650(1), b = 11.609(1), c = 21.884(3) Å, β = 117.07(1)°, and Z = 2. The structure was refined to R = 0.033 for 3 434 reflections. The solid-state structure shows two diphosphine ligands L1 bridging two rhodium(I) atoms to form a six-membered Rh2P4 ring in a chair conformation. Solution studies (1H and 13C-{1H} variable-temperature n.m.r. spectra) exhibit characteristics of a ring inversion equilibrium with ΔG271 = 14.0(0.2) kcal mol-1. Computer simulation of the 31P-{1H} n.m.r. spectrum is used to analyse the internuclear couplings of the AA′A″A‴XX′ pattern (A = 31P, X = 103Rh). The bridging diphosphine ligands exhibit a deshielding effect on the trans olefinic carbon atoms of cod in (1) which is in the range normally found for phosphine ligands.

Full Text

Duke Authors

Cited Authors

  • Crumbliss, AL; Topping, RJ; Szewczyk, J; McPhail, AT; Quin, LD

Published Date

  • January 1, 1986

Published In

Start / End Page

  • 1895 - 1899

International Standard Serial Number (ISSN)

  • 1472-7773

Digital Object Identifier (DOI)

  • 10.1039/DT9860001895

Citation Source

  • Scopus