Organolanthanides—XVI. Preparation and structure of bis(η 5-cyclopentadienyl)bis(triphenylphosphine oxide)ytterbium(II)—the first X-ray crystal structure of a phosphine oxideorganolanthanide(II) complex

Abstract

Reaction of Cp 2Yb(DME) (Cp = cyclopentadienyl; DME = 1,2-dimethoxyethane) with triphenylphosphine oxide yields Cp 2Yb(OPPh 3) 2. The X-ray crystal structure shows eight-coordinate ytterbium with a pseudo-tetrahedral arrangement of two oxygen donor atoms and the centroids of two eclipsed η 5-cyclopentadienyl rings. Surprisingly short Yb—O distances (2.30(2); 2.33(2) Å) and the absence of major inter-ligand contacts indicate an uncrowded arrangement.