Synthesis and X-ray Crystallographic Characterization of an Oxo-Bridged Bimetallic Organosamarium Complex, 2(μ-O)

Article abstract of DOI:10.1021/ja00288a021

<(C5Me5)2Sm>2(μ-O) is a common product in reactions of (C5Me2)Sm(THF)2 with oxygen-containing substrates such as NO, N2O, CH3CH2CHCH2O, or C5H5NO.The epoxide reaction, which liberates CH3CH2CH=CH2 as a byproduct, gives the best yield, 55percent. <(C5Me5)2Sm>2(μ-O) crystallizes from toluene/hexane under pentane diffusion at -3 deg C in space group I42m with unit cell dimensions a=11.560(5) Angstroem, c=14.236(6) Angstroem, and Z=2(dimers) for D_c=1.50 g cm^-3.Least-squares refinement on the basis of 962 observed reflections led to a final R value of 0.036.The two (C5Me5)2Sm units of the dimer are connected by a linear Sm-O-Sm bridge with Sm-O distances of 2.094(1) Angstroem.The centroids of the four C5Me5 rings define a tetrahedron which surrounds the Sm-O-Sm unit.The C5Me5 rings are in an eclipsed condormation on each samarium.In contrast to the above oxidation reactions, (C5Me5)2Sm(THF)2 reacts with OP(C6H5)3 to form the divalent adduct (C5Me5)2Sm(THF).