photochemical reduction of CO2 to formic acid catalyzed by a series of [Rh(4,4′-R-bpy)(Cp*)Cl]+ and [Rh(5,5′-COOH-bpy)(Cp*)Cl]+ complexes (Cp* = pentamethylcyclopentadienyl, bpy = 2,2′-bipyridine, and R = OCH3, CH3, H, COOC2H5, CF3, NH2, or COOH) was studied to assess how modifications in the electronic structure of the catalyst affect its selectivity, defined as the HCOOH:H2 product ratio. A direct molecular-level
一系列[Rh(4,4'-R-bpy)(Cp *)Cl] +和[Rh(5,5'-COOH-bpy)(Cp *)催化将CO 2光
化学还原为
甲酸研究了Cl] +配合物(Cp * =五
甲基环戊二烯基,bpy =
2,2'-联吡啶,R = OCH 3,CH 3,H,COOC 2 H 5,CF 3,NH 2或COOH),以评估修饰方式催化剂的电子结构中的H 2 O 3影响其选择性,定义为HCOOH∶H 2产物比。官能团对CO 2初始反应速率的直接分子
水平影响对质子还原反应。密度泛函理论计算首次阐明了[RhH]和[Cp * H]互变异构体的各自作用,认识到氢化
铑是这两个反应的关键因素。尤其是,我们的计算解释了观察到的给电子取代基通过降低Rh–H键的羟基而倾向于促进CO 2还原的趋势,与带有电子的取代基相比,导致向
甲酸生成的
氢化物转移势垒更低-抽出的性质更有利于将质子还原为氢。