Outer-Sphere Coordination Chemistry: Amido-Ammonium Ligands as Highly Selective Tetrachloridozinc(II)ate Extractants
作者:Jennifer R. Turkington、Violina Cocalia、Katrina Kendall、Carole A. Morrison、Patricia Richardson、Thomas Sassi、Peter A. Tasker、Philip J. Bailey、Kathryn C. Sole
DOI:10.1021/ic301691d
日期:2012.12.3
chloride concentration on extraction have demonstrated that the monoamides in particular show an unusually high selectivity for [ZnCl4]2- over [FeCl4]− and Cl–. Hybrid-DFT calculations on the tri-, di-, and monoamides, L2, L3, and L4, help to rationalize these orders of strength and selectivity. The monoamide L4 has the most favorable protonation energy because formation of the LH+ cation generates a “chelated
合成了八种新的酰胺基官能化试剂L 1 –L 8,其包含原子序列R 2 N–CH 2 –NR'–CO–R”,其在质子化时形成六元螯合物,在氢原子之间形成氢键。叔铵NH +基团和酰胺氧原子。单阳离子配体LH +通过一种机制从两个含有高浓度氯离子的酸性溶液中萃取四氯化金属(II),其中两个配体同时使用N-H和H-来处理[MCl 4 ] 2-单元的“外球”。C-H氢键供体,以形成中性配合物作为在2L + 2HCl的+的MC1 2 ⇌[(LH)2 MCl 4 ]。在这些依赖于pH的平衡中,作为锌萃取剂的L 1 –L 8的强度已非常依赖于R 3- n N(CH 2 NR'COR'')n分子中的酰胺基数量,随着存在的强氢键供体数量的增加,直觉递减,并遵循单酰胺>二酰胺>三酰胺的顺序。对氯化物浓度对萃取的影响的研究表明,特别是单酰胺对[ZnCl 4 ] 2-的选择性高于对[FeCl 4 ] -的选择性和Cl