Chromous siloxides of variable nuclearity and magnetism.

Treatment of Cr[N(SiMe)](thf) with HOSiR (R = Et, Pr) in THF afforded the bridged Cr siloxide complexes Cr(OSiEt)(μ-OSiEt)(thf) and Cr(OSiPr)(μ-OSiPr)(thf) in high yield. Exposure of these compounds to vacuum in aliphatic solvents led to the loss of coordinated THF and to the formation of the homoleptic chromous siloxides Cr(μ-OSiEt) and Cr(OSiiPr)(μ-OSiPr), respectively, in moderate to high yield. Use of TMEDA as a potentially bidentate donor molecule gave the monomeric -coordinated siloxide Cr(OSiiPr)(tmeda) (tmeda = ,,','-tetramethylethane-1,2-diamine).