Efficient removal of gold complexes from water by precipitation or liquid–liquid extraction using ionic liquids
Efficient removal of gold complexes from water by precipitation or liquid–liquid extraction using ionic liquids
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DOI：
10.1039/c2gc35222b
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发表时间：
2012-07
期刊：
影响因子：
9.8
通讯作者：
N. Papaiconomou;Ghislain Vite;N. Goujon;J. Lévêque;I. Billard
中科院分区：
文献类型：
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作者：
N. Papaiconomou;Ghislain Vite;N. Goujon;J. Lévêque;I. Billard
四氯金酸根或四溴金酸根阴离子的萃取已经在酸性pH值（1和4）下用几种带有卤化物或双（三氟甲磺酰基）酰亚胺NTf 2 −阴离子和阳离子1-辛基-3-甲基咪唑鎓、1-辛基吡啶鎓或1-甲基-1-辛基吡咯烷鎓的离子液体进行。首先通过混合含有金络合物和水溶性卤化物（氯化物或溴化物）离子液体的水溶液来研究从水中去除金阴离子部分。这导致形成固体沉淀物或对应于基于四卤代金酸根阴离子的疏水性离子液体的液相。含金离子液体的溶度积值低于10−6。研究了疏水性离子液体对阴离子型金配合物的液-液萃取。无论pH值和使用的离子液体如何，都成功地从水中提取了金。分布系数范围为3 × 102 ~ 3 × 104。对萃取机理的研究揭示了一个阴离子金络合物和一个NTf 2 −阴离子之间的阴离子交换。
Extraction of tetrachloroaurate or tetrabromoaurate anions has been carried out at acidic pHs (1 and 4) with several ionic liquids bearing halide or bis(trifluoromethanesulfonyl)imide NTf2− anions and cations 1-octyl-3-methylimidazolium, 1-octylpyridinium or 1-methyl-1-octylpyrrolidinium. The removal of gold anionic moieties from water was first studied by mixing aqueous solutions containing gold complexes and water soluble halide (chloride or bromide) ionic liquids. This lead to the formation of either a solid precipitate or a liquid phase corresponding to a hydrophobic ionic liquid based on a tetrahalogenoaurate anion. Values below 10−6 for the solubility products of gold-bearing ionic liquids were obtained. Liquid–liquid extraction of anionic gold complexes with hydrophobic ionic liquids was also carried out. Gold was successfully extracted from water whatever the pH and the ionic liquid used. Distribution coefficients ranged from 3 × 102 to 3 × 104. Investigation on the extraction mechanism revealed an anion exchange between one anionic gold complex and one NTf2− anion.