SYNTHESIS OF NEW BIS(CYCLOPENTADIENYL)YTTRIUM COMPLEXES WITH ETHER FUNCTIONALIZED CYCLOPENTADIENYL LIGANDS - CRYSTAL-STRUCTURE OF [(C(5)H(4)CH(2)CH(2)OME)(2)Y(MU-H)(2)BH2]

Treatment of C(5)H(4)CH(2)CH(2)OMe.Li(TMEDA) (TMEDA = N, N, N', N' tetramethylethylenediamine) with half an equivalent of YCl3(THF)(3.5) in toluene afforded the salt- and solvent-free dimeric biscyclopentadienyl yttrium chloride [(C(5)H(4)CH(2)CH(2)OMe)(2)Y-(mu-Cl)](2) (1). Reaction of 1 with one equivalent of LiAlH4 in THF gave the yttrium alumohydride complex [(C(5)H(4)CH(2)CH(2)OMe)(2)- YAlH4] (2), which was transformed into [(C(5)H(4)CH(2)CH(2)OMe)(2)Y(mu-H)](2) (4) by expulsion of AlH3 with NEt(3). Reaction of 1 with an excess of LiBH4 gave the yttrium borohydride complex [(C(5)H(4)CH(2)CH(2)OMe)(2)Y(mu-H)(2)BH2] (3), whose crystal structure has been shown to be monomeric species with yttrium-coordinated ether functions and a eta(2)-bonded borohydride ligand.