Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
Inorg Chem. 2012 Jun 18;51(12):6655-66. doi: 10.1021/ic300278v. Epub 2012 Jun 7.
A series of organometallic trialkylphosphine-stabilized copper gallium phenylchalcogenolate complexes [(R(3)P)(m)Cu(n)Me(2-x)Ga(EPh)(n+x+1)] (R = Me, Et, (i)Pr, (t)Bu; E = S, Se, Te; x = 0, 1) has been prepared and structurally characterized by X-ray diffraction. From their molecular structures three groups of compounds can be distinguished: ionic compounds, ring systems, and cage structures. All these complexes contain one gallium atom bound to one or two methyl groups, whereas the number of copper atoms, and therefore the nuclearity of the complexes, is variable and depends mainly on size and amount of phosphine ligand used in synthesis. The Ga-E bonds are relatively rigid, in contrast to flexible Cu-E bonds. The lengths of the latter are controlled by the coordination number and steric influences. The Ga-E bond lengths depend systematically on the number of methyl groups bound to the gallium atom, with somewhat shorter bonds in monomethyl compounds compared to dimethyl compounds. Quantum chemical computations reproduce this trend and show furthermore that the rotation of one phenyl group around the Ga-E bond is a low energy process with two distinct minima, corresponding to two different conformations found experimentally. Mixtures of different types of chalcogen atoms on molecular scale are possible, and then ligand exchange reactions in solution lead to mixed site occupation. In thermogravimetric studies the complexes were converted into the ternary semiconductors CuGaE(2). The thermolysis reaction is completed at temperatures between 250 and 400 °C, typically with lower temperatures for the heavier chalcogens. Because of significant release of Me(3)Ga during the thermolysis process, and especially in case of copper excess in the precursor complexes, binary copper chalcogenides are obtained as additional thermolysis products. Quaternary semiconductors can be obtained from mixed chalcogen precursors.
已制备并通过 X 射线衍射对一系列有机金属三烷基膦稳定的铜镓芳基硫族化合物 [(R(3)P)(m)Cu(n)Me(2-x)Ga(EPh)(n+x+1)] (R = Me, Et, (i)Pr, (t)Bu; E = S, Se, Te; x = 0, 1) 的结构进行了表征。根据其分子结构，可以将这些化合物分为三组：离子化合物、环系和笼状结构。所有这些配合物都含有一个镓原子与一个或两个甲基键合，而铜原子的数量，因此配合物的核性，是可变的，主要取决于合成中使用的膦配体的大小和数量。Ga-E 键相对刚性，而 Cu-E 键则灵活。后者的长度受配位数和空间位阻的影响。Ga-E 键长与与镓原子结合的甲基数量系统相关，与二甲基化合物相比，一甲基化合物的键略短。量子化学计算再现了这一趋势，并进一步表明，一个苯基基团围绕 Ga-E 键的旋转是一个低能过程，具有两个不同的最小值，对应于实验中发现的两种不同构象。在分子水平上混合不同类型的硫族原子是可能的，然后在溶液中进行配体交换反应导致混合位点占据。在热重研究中，配合物被转化为三元半导体 CuGaE(2)。热解反应在 250 至 400°C 之间完成，对于较重的硫族元素，温度通常较低。由于在热解过程中大量释放 Me(3)Ga，特别是在前体配合物中存在铜过剩的情况下，作为额外的热解产物获得了二元铜硫族化物。可以从混合硫族元素前体获得四元半导体。
