Investigation of the Effect of Oxy Bridging Groups in Dinuclear Zn(II) Complexes that Catalyze the Cleavage of a Simple Phosphate Diester RNA Analogue
作者:Mark F. Mohamed、Alexei A. Neverov、R. Stan Brown
DOI:10.1021/ic9015965
日期:2009.12.7
transition state for the cleavage of 2 than does 7:Zn(II)2 and that 4:Zn(II)2 affords 6.5 kcal/mol greater transition state stabilization than does 8:Zn(II)2. The analyses show that the reduction in the transition state stabilization experienced with the complexes having permanently bridging oxyanion groups stems almost entirely from a weaker binding of the phosphate and catalyst, and a reduced catalytic
制备了两组双核Zn(II)络合物,以确定金属中心之间氧阴离子桥接基团的存在对RNA类似物2-羟丙基-4-硝基苯基磷酸酯(HPNPP,2)对甲醇分解的催化活性的影响。。中的Zn(II)2种配合物的双(二- (2-吡啶基甲基)氨基) -米二甲苯(6)和2,6-二(二- (2-吡啶基甲基)氨基)-4-甲基苯酚(7)为比较以评估桥接酚盐配体的效果,而1,3-双-N 1-(1,5,9-三氮杂环十二烷基)-丙-2-醇的Zn(II)2络合物(8与先前研究的1,3-双-N 1-(1,5,9-三氮杂环十二烷基)-丙烷(4)的配合物相比,制备)来确定2-丙氧基的作用。对每个系统进行了2次裂解的详细动力学研究,包括k obs vs [催化剂]图和s s pH速率分布图以及电位滴定实验,以确定催化相关基团的酸解离常数。结果表明,在7:Zn(II)2中包含苯氧基桥联基团会降低二阶催化速率常数(k 2 cat),用于裂解C