Structural studies of lanthanide and yttrium metallocene oxides

Examination of the chemistry of sterically crowded (C5Me4R)3Ln complexes has provided access to a series of [(C5Me4R)2Ln]2(μ-O) complexes: [(C5Me5)2La]2(μ-O), [(C5Me5)2Nd(NC5H4NC4H8)]2(μ-O), [(C5Me4iPr)2Sm]2(μ-O), [(C5Me4Et)2Gd]2(μ-O), and [(C5Me5)2Sm(NC5H5)]2(μ-O). X-ray crystallographic data on these complexes provide information on the effect of metal and cyclopentadienyl ring size on LnO bond distances and LnOLn angles, which vary between 173 and 180° in these complexes.