Reaction of 1,3-diols with Al(tBu)3 and Ga(tBu)3: aluminium- and gallium-based bifunctional tetradentate ligands
作者:C. Niamh McMahon、Stephen J. Obrey、Andrea Keys、Simon G. Bott、Andrew R. Barron
DOI:10.1039/b000332h
日期:——
Reaction of M(tBu)3 (M = Al, Ga) with neol-H2 (2,2-dimethylpropane-1,3-diol) yields [M2(tBu)4(neol-H)2], M = Al (1) and Ga (2), respectively. Use of an equimolar mixture of Al(tBu)3 and Ga(tBu)3 allows for the formation of [AlGa(tBu)4(neol-H)2] (3). Compounds 1 and 2 may be considered as bifunctional (two OH groups), tetradentate (4O) ligands as highlighted by their reactivity with Group 13 hydrides and alkyls. Reaction of compound 1 with AlH3(NMe3), AlH2Cl(NMe3) and AlMe3 yields the tri-aluminium compounds, [Al3(tBu)4(X)(neol)2] with X = H (4), X = Cl (5), Me (6), respectively. Similarly, compound 2 reacts with Ga(tBu)3 to yield the tri-gallium compound, [Ga3(tBu)5(neol)2] (7). The mixed metal complexes, [Ga2Al(tBu)4(X)(neol)2], where X = H (8), Me (9) and tBu (10), are formed by the reaction of compound 2 with AlH3(NMe3), AlMe3, and Al(tBu)3, respectively. The solid state conformation of the neol backbone and the 1H NMR chemical shift of the neol's CH2 protons, in compounds 4–10, are both dependent on the steric bulk of the substituent of the central metal. Thermolysis of compound 2 in toluene results in the formation of [Ga3(tBu)4(CH2Ph)(neol)2] (11), while the reaction of 2 with LiOH in Et2O and hexane yields [Ga3Li4(tBu)6(neol)3(OH)(THF)] (12) and [Ga2Li(tBu)4(OH)2(neol-H)] (13), respectively. The molecular structures of compounds 1, 2, 4–13 and [Ga3Cl5(OSiMe2OSiMe2O)2] (14) have been determined by X-ray crystallography.
M(tBu)3(M = Al,Ga)与neol-H2(
2,2-二甲基丙烷-1,3
-二醇)的反应生成了[M2(tBu)4(neol-H)2],其中M = Al(1)和Ga(2)。使用等摩尔的Al(tBu)3和Ga(tBu)3的混合物可以形成[AlGa(tBu)4(neol-H)2](3)。化合物1和2可视为双功能(两个OH基团)、四齿(4O)
配体,这一点通过它们与第13族
氢化物和烷基的反应得到了强调。化合物1与
AlH3(NMe3)、AlH2Cl(NMe3)和AlMe3的反应生成三铝化合物[Al3(tBu)4(X)(neol)2],其中X = H(4)、X = Cl(5)、Me(6),分别。类似地,化合物2与Ga(tBu)3反应生成三
镓化合物[Ga3(tBu)5(neol)2](7)。混合
金属络合物[Ga2Al(tBu)4(X)(neol)2],其中X = H(8)、Me(9)和tBu(10),分别是通过化合物2与 (NMe3)、AlMe3和Al(tBu)3的反应形成的。在化合物4至10中,neol骨架的固态构象和neol的
CH2质子的1H NMR
化学位移都依赖于中心
金属替代基的立体体积。化合物2在
甲苯中的热解反应生成[Ga3(tBu)4( Ph)(neol)2](11),而化合物2与LiOH在Et2O和己烷中的反应分别生成[Ga3Li4(tBu)6(neol)3(OH)(THF)](12)和[Ga2Li(tBu)4(OH)2(neol-H)](13)。化合物1、2、4-13和[Ga3Cl5(OSiMe2OSiMe2O)2](14)的分子结构已通过X射线晶体学确定。