化学模拟生物固氮——Ⅵ.铁钼辅基模型化合物的合成及其催化性能

Abstract

[中文文摘]本文讨论了先前我们提出的固氨酶活性中心骈联双座双立方烷原子簇结构模型的一些特征。根据这一模型。设计了铁钼辅基模型化合物的合成方案,合成了三系列的铁钼辅基模型化合物,其Mo、S~*、Fe之比如同这一模型所要求的,为1:～6:6～8。由氯化物系列和柠檬酸盐进行配位体交换而得到的柠檬酸盐系列中的两个样品,在KBH_4还原C_2H_2为C_2H_4的反应中具有很高的催化活性(按每个Mo计算,转变数为20～30分~(-1))和选择性(91～95％),接近天然的铁钼辅基的水平,并在与Av突变种UW_(45)重组后,按Shah和Brill的方法测定,显示出明显的固氮酶活性。[英文文摘]Some features of the twin-sited dicubane-clurter structural model of nitrogenase active-center previously proposed by us are diseased. Based upon this model, a method for the synthesis of FeMo-co modeling compounds has been designed.Three series of FeMo-co modeling compounds have been synthesized, with Mo : S*: Fe=l:-6 :6-8 as required by the model. Two samples of the citrate series, obtained by ligand exchange of the chioridc series with citrate, have been found to exhibit very high catalytic activity (tur-over number per Mo:20~30min-1)and selectivity (92-95%C2H4),approaching that of FeMo-co,in the reduction of C2H4 to C2H4 by KBH4,and to show a certain well-confirmed nitrogenase activity as assayed by Shah and Bill's method after reconstitution with Av mutant UW45.