The complex [(iPr3PCu)2(Me2Ga)2(SCH2CH2S)2] (4) was synthesized from trimethylgallium, [(iPr3PCu)4(SCH2CH2S)2] (1) and ethanedithiol by elimination of methane. The related monomethyl compound [(iPr3PCu)2(MeGaSPh)2(SCH2CH2S)2] (5) has been prepared from [(iPr3PCuSPh)3] (2) and [(MeGaSCH2CH2S)2] (3) by a ligand exchange reaction in tetrahydrofuran solution. The molecular structures of 1 and 3â5 were determined by single crystal X-ray diffraction. Thermolysis of 4 and 5 results in the formation of the ternary semiconductor CuGaS2, gallite. The residue of 5 was characterized using X-ray powder diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy. The CuGaS2 crystals obtained are mainly hexagonal plates of around 200 to 300 nm diameter and 10 to 30 nm thickness, exhibiting an unusual metastable hexagonal crystal structure, related to wurtzite. Partially, the usual tetragonal chalcopyrite structure or its disordered cubic zinc-blende analogue is realized by stacking faults, resulting in an overall similarity to the zinc-blendeâwurtzite polytypism in ZnS and related compounds.
复合物[(iPr3PCu)2(Me2Ga)2(SCH2CH2S)2] (4)是通过去除
甲烷,从
三甲基镓、[(iPr3PCu)4(SCH2CH2S)2] (1)和乙二
硫醇合成的。相关的单甲基化合物[(iPr3PCu)2(MeGa
SPh)2(SCH2CH2S)2] (5)则是通过在
四氢呋喃溶液中进行
配体交换反应,由[(iPr3PCu
SPh)3] (2)与[(MeGaSCH2CH2S)2] (3)制备的。化合物1和3–5的分子结构通过单晶X射线衍射确定。化合物4和5的热分解产生了三元半导体CuGaS2(
镓铝矿)。利用X射线粉末衍射、能量色散X射线光谱和透射电子显微镜对5的残留物进行了表征。获得的CuGaS2晶体主要为直径约200至300纳米、厚度为10至30纳米的六角形薄片,展现出一种不寻常的亚稳六角晶体结构,相关于闪
锌矿。通常的四方
黄铜矿结构或其无序立方闪
锌矿类似体通过堆垛缺陷得以实现,导致其在整体上与ZnS及相关化合物的闪
锌矿–闪
锌矿多型性相似。