［顺－二羰基（N－2－（2－吡啶）乙基芳胺）铑］的四苯硼酸盐的合成及其催化性能  

Preparation and Catalytic Activity of cis-[Dicarbonyl-(N-2-(2-Pyridyl) ethylarylamine) rhodium] Tetraphenylborate

作　　者：袁国卿[1] 潘平来[1] 柳忠阳[1] 黄茂开[1] 陈荣耀[1] 

机构地区：[1]中国科学院化学研究所

出　　处：《分子催化》1995年第4期278-284,共7页Journal of Molecular Catalysis(China)

摘　　要：［顺－二羰基（Ｎ－２－（２－吡啶）乙基对取代苯胺）铑］的四苯硼酸盐作为催化剂，用于催化甲醇羰基化反应，在温和的条件下，可顺利催化甲醇羰基化反应得到乙酸和乙酸甲酯而无其它副产物．若以甲醇和乙酸的混合液作反应物，则得到乙酸酐和乙酸甲酯．即使在大量水存在下，也仅有微量的水煤气转换反应发生．实验证明对位取代基团的电子效应对铑配合物的催化活性影响甚微．在不同位置以不同链长相联的二吡啶配体对铑阳离子配合物性能的影响是明显的．其中α，α＇－联吡啶铑阳离子结构不利于催化反应的进行．由此证明，作为催化剂活性物种除必须的Ｒｈ－ＣＯ键存在外，配体的空间结构是影响配合物活性的决定因素．羰基化发生在碘甲烷的氧化加成与乙酰碘的还原消除之间，同时还伴有一个在配位的乙酰基与铑的顺－空配位之间甲基的１，２移动变化．cis-[Dicarbonyl-(N-2-(2-pyridyl) ethyl-p-substituted aniline)rhodium] tetraphenylborates have been investigated as a model active rhodium cationic species for the carbonylation of methanol. The catalytic reaction took place smoothly to yield acetic acid and methyl acetate without other byproducts.The electronic effect of the para-substituents appears to show very little, if any,difference in the catalytic activity of the rhodium complexes.cis-Dicarbonylrhodium cations coordinated with two pyridyl radicals connected at different positions with mono-,di-and trimethylene chain have also been studied as the active species for the same reaction. The lengths of the carbon chain do exert some but definite infiuence on the activity even though these complexes are less active than those mentioned above, Coordination with α,α'-bipyridyl resulted in a deteriorated effect on the catalytic activity. It is deduced that the presence of Rh -Co bond in the catalyst is a necessary but not sufficient condition for an active species. The Ndonors with a steric arrangement facilitating a fluxional structure might also be a determining condition for the active species.The carbonylation reaction might proceed via a reversible 1,2-migration of the methyl group between the coordinated acetyl group and a cis-coordination site on the rhodium atom as the intermediate stage between the oxidative addition of methyl iodide and reductive elimination of acetyl iodide.

关 键 词：铑配合物 催化剂 四苯硼酸盐 合成 催化性能 

分 类 号：TQ426.92[化学工程]