Department of Chemistry, Royal Institute of Technology (KTH), Teknikringen 30, 10044 Stockholm (Sweden).
Chemistry. 2010 Apr 19;16(15):4659-68. doi: 10.1002/chem.200902603. Epub 2010 Mar 12.
Two mononuclear ruthenium complexes [RuL(pic)3] (1) and [RuL(bpy)(pic)] (2) (H2L = 2,6-pyridinedicarboxylic acid, pic = 4-picoline, bpy =2,2'-bipyridine) have been synthesized and fully characterized. Both complexes could promote water oxidation chemically and photochemically. Compared with other known ruthenium-based water oxidation catalysts using [Ce(NH4)2(NO3)6] (Ce(IV)) as the oxidant in solution at pH 1.0, complex 1 is one of the most active catalysts yet reported with an initial rate of 0.23 turnover s(-1). Under acidic conditions, the equatorial 4-picoline in complex 1 dissociates first. In addition, ligand exchange in 1 occurs when the Ru(III) state is reached. Based on the above observations and MS measurements of the intermediates during water oxidation by 1 using Ce(IV) as oxidant, RuL(pic)2(H2O) is proposed as the real water oxidation catalyst.
合成并充分表征了两个单核钌配合物[RuL(pic)3]（1）和[RuL(bpy)(pic)]（2）（H2L=2,6-吡啶二甲酸，pic=4-吡啶，bpy=2,2'-联吡啶）。这两个配合物都可以通过化学和光化学方法促进水氧化。与其他已知的以[Ce(NH4)2(NO3)6]（Ce(IV)）为氧化剂、在 pH=1.0 的溶液中用于水氧化的基于钌的水氧化催化剂相比，配合物 1 是报道的最活跃的催化剂之一，其初始速率为 0.23 转/秒。在酸性条件下，配合物 1 中的赤道 4-吡啶首先解离。此外，当达到 Ru(III)态时，配体在 1 中发生交换。基于上述观察和使用 Ce(IV)作为氧化剂时 1 对水氧化的中间体的 MS 测量，提出[RuL(pic)2(H2O)]+是真正的水氧化催化剂。
