ALLYL DERIVATIVES OF [(TI(ETA(5)-C(5)ME(5))(MU-O)(CL))(3)] - X-RAY CRYSTAL-STRUCTURE OF [(TI(ETA(5)-C(5)ME(5))(MU-O)(CH2CH=CHME))(3)]

Reactions of [{Ti(eta(5)-C(5)Me(5))(mu-O)Cl}(3)] (1) with Grignard rea gents, RMgCl (R = allyl(CH2CH=CH2), crotyl (CH2CH=CHMe)), in diverse r atios and conditions allow the characterization of the allyl oxotrimer s [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)R(n)Cl(3-n)] (n = 3, R = allyl, 2; n = 1, R = allyl, 4; n = 2, R = allyl, 5; n = 3, R = crotyl, 7). The co mplexes [{Ti(eta(5)-C(5)Me(5))(mu-O)}(3)(pi-C3H5)(3)] (2) and [{Ti(eta (5)-C(5)Me(5))(mu-O)}(3)(pi-C3H5)(2)Cl] (5) undergo thermal rearrangem ents, in a regio- and stereoselective way, to give the derivatives -C( 5)Me(5))(mu-O)}(3){mu(2)-CH2CH(CH2CH=CH2)CH2}X] X = allyl (3) and X = Cl (6) respectively. These processes involve the migration of one ally l group to the beta-carbon of the adjacent allyl ligand and the format ion of a 2-allyl-1,3-propanediyl unit bridging two titanium atoms. The crystal structure of (eta(5)-C(5)Me(5))(mu-O)}(3)(sigma-CH2CH=CHMe)(3 )] (7) has been studied by X-ray crystallography and can be described as three Ti(eta(5)-C(5)Me(5))(sigma-crotyl) units linked through oxyge n bridges forming a nearly planar Ti3O3 ring.