循环经济的需求推动了新的、环境友好的金属金溶解方法的开发。金广泛用于消费电子产品,但金的可持续和选择性溶解方法很少。在此,我们描述了使用过氧化氢作为氧化剂在温和条件下定量溶解金在有机溶液中。在溶解反应中,两个硫醇配体,吡啶-4-硫醇和2-巯基苯并咪唑以协同方式起作用。机理研究表明,两个吡啶-4-硫醇分子与可被氧化的 Au 0形成复合物,而廉价的 2-巯基苯并咪唑的作用是通过配体交换过程稳定形成的 Au 物质。在优化的条件下,反应剧烈进行,金在两小时内定量溶解。所证明的两种硫醇的配体交换机制可以大大减少硫醇的消耗,并可能在未来带来更有效的金溶解方法。
Coordination of Pyridinethiols in Gold(I) Complexes
摘要:
High-yield synthesis of gold(I) thionato complexes, bis(pyridine-2-thionato)gold(I) chloride (1) and bis(pyridine-4-thionato)gold(I) chloride (2), are described. According to their solid-state structures, a linear coordination of Au(I), equiplanar coordination of the ligands and two weak gamma-agostic interactions are found in both of these complexes despite of different relative positions of N and S atoms in the pyridinethionato ligands. Density functional theory calculations on 1 and 2 reproduce the observed X-ray structures. Even though the C-H...Au interactions of Au(I) and two pyridine moieties (2.83 and 2.88 A in 1 and 2.86 A in 2) are relatively weak, according to calculations they seem to provide further stabilization for the coordination and orientation of the ligands. In 1 the shortest Au...Au distances of 3.50 A indicate that aurophilic interactions, even though weak, are present in the solid state, whereas in 2 these interactions are absent.