Treatment of the salicylaldimine ligands 3,5-But2-2-(OH)C6H2CHNR [R = 2,6-Me2C6H3 (1a), 2,6-Pri2C6H3 (1b), 3,5-(CF3)2C6H3 (1c), 4-(NO2)C6H4 (1d), 4-ClC6H4 (1e), 1-naphthyl (1f), But (1g)] with Me3Al in toluene yields, after work-up, the highly crystalline (except 2c
– an oil) complexes 3,5-But2-2-(O)C6H2CHNR}AlMe2
[R = 2,6-Me2C6H3 (2a), 2,6-Pri2C6H3 (2b), 3,5-(CF3)2C6H3 (2c), 4-(NO2)C6H4 (2d), 4-ClC6H4 (2e), 1-naphthyl (2f), But (2g)] respectively. Reaction of these systems with B(C6F5)3 in the presence of THF leads smoothly to [3,5-But2-2-(O)C6H2CHNR}AlMe(THF)]+ [R = 2,6-Me2C6H3 (3a), 2,6-Pri2C6H3
(3b), 3,5-(CF3)2C6H3 (3c), 4-(NO2)C6H4 (3d), 4-ClC6H4 (3e), 1-naphthyl (3f), But (3g)], as the B(C6F5)3Me− salts. By contrast, the same reaction performed in dichloromethane solution without THF gives complex mixtures: the NMR spectrum of the product mixture obtained from the reaction of 2g with B(C6F5)3 in CD2Cl2 indicated, inter alia, the presence of both 3,5-But2-2-(O)C6H2CHNBut}AlMe(C6F5)]
and B(C6F5)2Me. Compounds 2a and 2b have been characterised by single crystal X-ray structure determinations and shown to have virtually identical conformations. In both systems there is a marked distortion in the tetrahedral geometry at the aluminium centre.
将
水杨醛亚胺配体3,5-But2-2-(OH)C6H2CHNR [R = 2,6-Me2C6H3 (1a), 2,6-Pri2C6H3 (1b), 3,5-(
CF3)2C6H3 (1c), 4-(
NO2)
C6H4 (1d), 4-Cl (1e), 1-
萘基 (1f), But (1g)]与
甲苯中的Me3Al反应,经后处理得到高度结晶(除2c为油状物外)的配合物3,5-But2-2-(O)C6H2CHNR}AlMe2 [R = 2,6-Me2C6H3 (2a), 2,6-Pri2C6H3 (2b), 3,5-( )2C6H3 (2c), 4-( ) (2d), 4-Cl (2e), 1-
萘基 (2f), But (2g)]。在这些体系中加入THF并反应B(
C6F5)3,顺利得到[3,5-But2-2-(O)C6H2CHNR}AlMe(THF)]+ [R = 2,6-Me2C6H3 (3a), 2,6-Pri2C6H3 (3b), 3,5-( )2C6H3 (3c), 4-( ) (3d), 4-Cl (3e), 1-
萘基 (3f), But (3g)],即B( )3Me−盐。相比之下,在没有THF的
二氯甲烷溶液中进行相同的反应得到复杂的混合物:从2g与B( )3在CD2Cl2中的反应获得的产品混合物的NMR谱表明,其中存在3,5-But2-2-(O)C6H2CHNBut}AlMe( )]和B( )2Me。化合物2a和2b已通过单晶X射线结构确定法表征,并显示出几乎相同的构象。在这两个体系中,铝中心的四面体几何结构都存在明显的畸变。