HOMONUCLEAR AND HETERONUCLEAR HYDRIDO LUTETIECENE COMPLEXES WITH BULKY 1,3-DI(TERT-BUTYL)CYCLOPENTADIENYL (C5H3TBU2) LIGANDS - THE MOLECULAR-STRUCTURE OF [(TERT-BU2C5H3)LUH]4[ALH4.ET2O]2[ALH4]2

Reactions occurring in the system (Cp"2LuCl)2-MAlH4-L-solvent have been studied. It has been shown that the aluminohydride complexes (Cp"2LnAlH4.L)2 formed are unstable and decompose, depending on reaction conditions, along three pathways: (a) desolvation, (b) dissociation of solvated aluminium hydride and (c) destruction of the cene moiety to produce the polynuclear monocyclopentadienyl hydridoaluminohydridic complex [(tBu2C5H3)LuH]4[AlH4.Et2O]2[AlH4]2 (XII). Similar reaction of the departure of one of the cyclopentadienyl ligands is observed in (Cp"2LuCl)2 when it dissolved in aromatic solvents. Crystals of XII are triclinic: a = 11.616(2), b = 14.822(2), c = 24.236(5) angstrom, alpha = 87.51(1), beta = 100.59(1), gamma = 75.83(1)-degrees, space group P1BAR, Z = 2. XII is characterized by the previously unknown tetrahedral metal core made of Lu atoms bound by bridging hydrogens and tri- (AlH4) and tetra-dentate (AlH4.Et2O) groups.