The Thermal Average Molecular Structures of Bis(pentamethylcyclopentadienyl)magnesium(II), -calcium(II) and -ytterbium(II) in the Gas Phase.

Abstract

The thermal average molecular structures of the three compounds Mg(C5Me5)2, Ca(C5Me5)2 and Yb(C5Me5)2 (Me=CH3) have been determined by gas phase delectron diffraction (GED). Mg(C5Me5)2 has a regular sandwich structure where the predominant conformation (D5d symmetry) cannot be ruled out. In contrast, Ca(C5Me5)2 and Yb(C5Me5)2 can best be described as bent samdwich molecules in which the angle between the two ring planes,