文摘
The synthesis of a range of alkyl/chloro-gallium alkoxide and amido/alkoxide compounds was achieved via a series of protonolysis and alcoholysis steps. The initial reaction involved the synthesis of [Me(Cl)Ga{N(SiMe3)2}]2 (1) via methyl group transfer from the reaction of GaCl3 with two equivalents of LiN(SiMe3)2. Reaction of 1 with varying amounts of ROH resulted in the formation of [Me(Cl)Ga(OR)]2 (2, R = CH2CH2OMe; 3, CH(CH3)CH2NMe2), [Me(Cl)Ga{N(SiMe3)2}(渭2-OR)Ga(Cl)Me] (4, R = CH2CH2NMe2), or [MeGa(OR)2] (5, R = CH(CH3)CH2NMe2). Compound 4 represents an intermediate in the formation of dimeric complexes, of the type [Me(Cl)Ga(OR)]2, when formed from compound [Me(Cl)Ga{N(SiMe3)2}]2. A methylgallium amido/alkoxide complex [MeGa{N(SiMe3)2}(OCH2CH2OMe)]2 (6) was isolated when 2 was further reacted with LiN(SiMe3)2. In addition, reaction of 2 with HOtBu resulted in a simple alcohol/alkoxide exchange and formation of [Me(Cl)Ga(OtBu)]2 (7). In contrast to the formation of 1, the in situ reaction of GaCl3 with one equivalent of LiN(SiMe3)2 yielded [Cl2Ga{N(SiMe3)2}]2 in low yield, where no methyl group transfer has occurred. Reaction of alcohol with [Cl2Ga{N(SiMe3)2}]2 was then found to yield [Cl2Ga(OR)]2 (8, R = CH2CH2NMe2), and further reaction of 8 with LiN(SiMe3)2 yielded the gallium amido alkoxide complex, [ClGa{N(SiMe3)2}(OR)]2 (9, R = CH2CH2NMe2), similar to 6. The structures of compounds 4, 5, 7, and 8 have been determined by single-crystal X-ray diffraction.