Alkene-like rotation of unsaturated Rh2 and CoRh fragments when bonded to molybdenum pentacarbonyl; X-ray crystal structure of [MoRh2(µ-CO)2(CO)5(η-C5Me5)2]

Abstract

Studies (¹³ C{¹H} n.m.r. and X-ray diffraction) on the compounds [MMoRh(µ-CO)₂(CO)₅(η-C₅Me₅)₂](M = Co or Rh) show that the preferred orientation of the MRh groups with respect to the cis-CO ligands of the Mo(CO)₅moiety is staggered, but in the CoMoRh species rotation occurs in solution about an axis through the Mo and the mid-point of the Co–Rh vector.