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[摘要]：Reactions of [La(AlMe4)3] and [Y(AlMe4)3] with PMe3 show that the phosphine can cleave Ln-CH3-Al linkages, sepg. Me3Al(PMe3). PMe3 (3 mol equiv) reacts with [Y(AlMe4)3] to give [(YMe3)n] contaminated with byproducts contg. P and Al. The La-based analog, [(LaMe3)n], is not formed selectively from the reaction of [La(AlMe4)3] with PMe3 or Et2O, which rather yields insol. La/Al heterobimetallic products. Three multi-nuclear La-based clusters were obtained from a reaction of [La(AlMe4)3] with PMe3 (1 equiv) and identified by x-ray structure analyses. Each cluster exhibits extensive Me group degrdn. and contains methylene, methine, or carbide moieties. [La4Al8(CH)4(CH2)2Me20(PMe3)] has a {La4(CH)4} cuboid core supported by AlMe3, Me2AlCH2AlMe2, and PMe3 ligands. [La4Al8(C)(CH)2(CH2)2Me22(toluene)] also contains a cuboid core, [La3Al(C)(CH)2(CH2)], which includes one exo cubic La atom, and is supported by AlMe3, Me3AlCH2AlMe2, (AlMe4)-, and toluene ligands. The La atoms in [La5Al9(CH)6Me30] are arranged in a trigonal bipyramidal fashion with (CH) functionalities capping each face. The {La5(CH)6}3- core is formally balanced by three AlMe2+ moieties and is addnl. supported by six AlMe3 ligands. The unit cell contains two independent La5 clusters, one with pseudo-C3h and the other with pseudo-D3 symmetry, as well as two mols. of the sepn. coproduct Me3Al(PMe3). |
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