Synthesis of Phosphonic Acid Derivatized Bipyridine Ligands and Their Ruthenium Complexes
摘要:
Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine and 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy)(2)(Pbpy)](2+), [Ru(bpy)(Pbpy)(2)](2+), [Ru(Pbpy)(3)](2+), [Ru(bpy)(2)(CPbpy)](2+), [Ru(bpy)(CPbpy)(2)](2+), and [Ru(CPbpy)(3)](2+) [bpy = 2,2'-bipyridine; Pbpy = 4,4'-bis(phosphonic acid)-2,2'-bipyridine; CPbpy = 4,4'-bis(methylphosphonic acid)-2,2'-bipyridine].
CO<sub>2</sub> Hydrogenation Catalyzed by a Ruthenium Protic N-Heterocyclic Carbene Complex
作者:M. Cecilia Johnson、Dylan Rogers、Werner Kaminsky、Brandi M. Cossairt
DOI:10.1021/acs.inorgchem.1c00417
日期:2021.4.19
We describe the hydrogenation of CO2 to formate catalyzed by a Ru(II) bis(protic N-heterocyclic carbene, p-NHC) phosphine complex [Ru(bpy)(MeCN)(PPh(p-NHC)2)](PF6)2 (1). Under catalytic conditions (20 μmol catalyst, 20 bar CO2, 60 bar H2, 5 mL THF, 140 °C, 16 h), the activity of 1 is limited only by the amount of K3PO4 present in the reaction, yielding a nearly 1:1 ratio of turnover number (TON) to
我们描述了通过Ru(II)双(质子N-杂环卡宾,p-NHC)膦络合物[Ru(bpy)(MeCN)(P Ph(p-NHC)2)]催化CO 2氢化成甲酸酯PF 6)2(1)。下催化条件(20微摩尔催化剂,20巴CO 2,60巴ħ 2,5毫升THF中,140℃,16小时),活性1仅由K的量的限制3 PO 4存在于反应,产生的周转率(TON)与当量K 3 PO 4(相对于1)的比率接近1:1),最高TON =8040。此外,对运行后反应溶液的分析表明,催化剂完好无损,未观察到游离配体。进行了化学计量学研究,包括检查独特的氨基甲酸酯和氢化物配合物作为相关中间体,以探测其作用机理并了解该系统中金属-配体协同作用的重要性。