Diiodotrimethylarsine, Me3AsI2, was treated with cobalt or nickel metal powder to give the metal(III) complex, [MI3(AsMe3)2]. In the case of cobalt, a metal(II) complex, [AsMe3I][CoI3(AsMe3)], was also produced, whereas for the nickel reaction only the nickel(III) complex, [NiI3(AsMe3)2], was formed in quantitative yield. The only other product from the reactions was diiodine, which was detected spectrophotometrically. Both complexes have been crystallographically characterised and found to be isostructural, consisting of a metal(III) atom with three equatorial iodide ligands capped by two trimethylarsine ligands. These complexes are unique examples of X-ray structural characterisation of compounds of this stoichiometry. Conventional wisdom would not have expected the ‘soft’ ligands I– and AsMe3 to bind to the relatively hard metal(III) centre.
用
钴或
镍金属粉末处理二
碘三甲基胂 Me3AsI2,可得到
金属(III)络合物 [MI3(AsMe3)2]。在
钴反应中,还生成了
金属(II)络合物 [AsMe3I][CoI3(AsMe3)],而在
镍反应中,只生成了定量的
镍(III)络合物 [NiI3(AsMe3)2]。反应中唯一的其他产物是二
碘,它是通过分光光度法检测到的。对这两种配合物进行了晶体学表征,发现它们结构相同,都是由一个
金属(III)原子与三个赤道
碘配体和两个
三甲基胂配体组成。这些复合物是对这种
化学计量的化合物进行 X 射线结构表征的独特实例。传统观点认为,"软 "
配体 I- 和 AsMe3 不会与相对较硬的
金属(III)中心结合。