(4). Homovalent 1 and 2 exhibited catalytic activity towards proton reduction in the presence of acetic acid (AcOH) as the substrate. The complexes are stable in solution while their catalytic turnover frequency is estimated at 10 and 34.6 h−1 molcat−1 for 1 and 2, respectively. Calculations reveal one-electron reduction of 1 is ligand-based, preserving the dicobalt(II) core and activating the ligand
手性羰基二
钴(II)配合物[CO II 2(μ 2 -L)2 ](1)(H 2 L = Ñ 2,Ñ 6 -二(
喹啉-8-基)
吡啶-2,6-二甲酰胺)和其叔丁基类似物[CO II 2(μ 2 -L卜)2 ](2)的合成和结构表征。在1和2的
二氯甲烷溶液中添加一当量的AgSbF 6导致分离出混合价的二
钴III,II)物种[CO III
钴II(μ 2 -L)2 ]的SbF 6(3)和[CO III
钴II(μ 2 -L卜)2 ]的SbF 6(4)。在
乙酸(AcOH)作为底物的存在下,同价物1和2对质子还原表现出催化活性。该配合物在溶液中稳定,而其催化转换频率估计为10和34.6 h -1 mol cat -1的1和2。计算揭示的单电子还原1是配位体为基础,保留二
钴(II)芯和在
喹啉基激活朝向质子化的
配体。这产生了空的配位位点,其随后被质子化以产生催化普遍存在的氢化Co(III)。双核结构持续存在,