Mechanistic study on dehydrogenation of methanol with [RuCl2(PR3)3]-type catalyst in homogeneous solutions
作者:Li-Chang Yang、Takashi Ishida、Tetsu Yamakawa、Sumio Shinoda
DOI:10.1016/1381-1169(96)00003-9
日期:1996.5
Catalytic dehydrogenation of methanol has been investigated in homogeneous solutions with a series of Ru(II) complexes, [RuCl2(P(p-C6H4X)3)3] (X = H (1), Me (2), F (3), OMe (4)) and [RuCl2(PMePh2)3] (5). In the gas phase, hydrogen was formed selectively (> 99.5%), and formaldehyde, methylal (formaldehyde dimethyl acetal) and methyl formate were found in the liquid phase with satisfactory stoichiometry
在具有一系列Ru(II)配合物[RuCl 2(P(p -C 6 H 4 X)3)3 ](X = H(1),Me(2) ,F(3),OMe(4))和[RuCl 2(PMePh 2)3](5)。在气相中,选择性地形成了氢气(> 99.5%),并且在液相中发现了甲醛,甲基缩醛(甲醛二甲基乙缩醛)和甲酸甲酯,对形成的氢气具有理想的化学计量比。通过额外添加游离膦来阻碍反应,这表明存在膦配体的预平衡解离。从该观点进行的动力学分析很好地解释了速率对催化剂浓度的依赖性(饱和曲线)。评估的平衡前常数的顺序(1≈2> 5)符合以下一般思想:膦配体的离解主要受配体的空间体积控制。1-4的速率顺序(3> 1> 2> 4),具有与膦配体相同的锥角,与膦的碱度明显相关。3个中级。