Gold oxidative dissolution by (thioamide)-I2 adducts
Gold oxidative dissolution by (thioamide)-I2 adducts
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DOI：
10.1039/c2dt31855e
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发表时间：
2013-01-01
影响因子：
4
通讯作者：
Lippolis, Vito
中科院分区：
文献类型：
--
作者：
Isaia, Francesco;Aragoni, M. Carla;Lippolis, Vito
Elemental gold powder is easily oxidised under mild reaction conditions with 1 : 1 I-2-adducts of the thioamides 3-methyl-benzothiazole-2-thione (mbtt) and 1-methyl-1H-benzimidazole-2(3H)-thione (mbit) with separation of the ionic complexes [Au-I(mbtt)(2)]I-3 (1) and [(mtbiH)(2)](AuI4)I-3 (2) [mtbiH = the imido protonated form of 2-(methylthio) benzimidazole] (gold oxidation yield > 78% and 45%, respectively). The X-ray crystal structure of 1 shows the Au(I) centre linearly bound by two neutral ligands via the sulphur atom, whereas the X-ray crystal structure of 2 shows the Au(III) centre surrounded by four iodides in a square-planar arrangement. The oxidising/complexing properties of the mbtt center dot I-2 and mbit center dot I-2 adducts were interpreted considering the S-donor to I-2 interaction that leads to a charge separation between the Ib and It iodine atoms in the fragment S-I-b-I-t. The oxidation of gold in a non-aqueous solvent by thioamide-I-2 adducts could be a promising alternative process to the numerous hydrometallurgical ones for the recovery of gold from secondary sources.
