ORGANOLANTHANIDE HYDROXIDES - THE SYNTHESIS AND CRYSTAL-STRUCTURES OF THE SAMAROCENE AND YTTERBOCENE HYDROXIDES [(SMCP''2(MU-OH))2] AND [(YBCP'2(MU-OH))2][CP''=ETA-5-C5H3(SIME3)2-1,3 - CP'=ETA-5-C5H4SIME3]

The organolanthanide(III) complexes [{SmCp2''(mu-OH)}2] (1) and [{YbCp2'(mu-OH)}2] (2) [Cp'' = eta-5-C5H3(SiMe3)2-1,3; Cp' = eta-5-C5H4SiMe3] were prepared from the appropriate lanthanocene(II) precursor [SmCp2''(THF)] (3) and [YbCp2'(OEt2)] (4), by treatment with water in an ethereal solution. The single crystal X-ray structures of 1 and 2 reveal that each complex is dimeric with bridging hydroxide groups, while NMR data indicate that these structures persist in aprotic media. The mean bond lengths Sm-O 2.40(2) and Sm-Cent(Cp'') 2.45 angstrom in crystalline 1 may be compared with Yb-O 2.29(2) and Yb-Cent(Cp') 2.33 angstrom in 2; while the angle O-Sm-O' in 1 is 76.6(6) and O-Yb-O' in 2 is 77.9(7)degrees (''Cent'' refers to the centroid of the C5 ring).