Cleavage of an RNA Model Catalyzed by Dinuclear Zn(II) Complexes Containing Rate-Accelerating Pendants. Comparison of the Catalytic Benefits of H-Bonding and Hydrophobic Substituents
作者:Mark F. Mohamed、R. Stan Brown
DOI:10.1021/jo1017316
日期:2010.12.17
stronger binding than the parent complex. In terms of the overall second order catalytic rate constant, the CH3, amino, and NH(C═O)CH3 groups provide 20, 10, and 68 times the k2cat observed for the parent complex. In the case of 9:Zn(II)2, the presence of the methyl groups provides a 1000-fold increase in activity (judged by k2cat) over the parent complex 8:Zn(II)2. The results are interpreted to indicate
一个简单的模型RNA,2-羟丙基的酯交换p硝基苯基磷酸盐(2,HpNPP)七个双核锌(II)催化剂(促进3,4,5,6,7,8,9:锌(II)2:基于双[双(2-(2-取代-吡啶基-6-甲基)]胺配体系统的(-OCH 3))在甲醇中于s s pH控制的条件下于25.0±0.1°C下进行了研究。两个金属络合配体经由连接在一起的氨基N接一个米-二甲苯接头(3,4,5,6,7),其中2-吡啶基取代基= H,CH 3,(CH)4,NH 2,和NH(C = O)CH 3分别和丙基接头(8,9),其中所述环取代基= H和CH 3。除8:Zn(II)2以外,所有双核络合物均表现出k obs与[催化剂]图的饱和动力学关系,从中可以确定催化剂:底物的结合常数(K M),其分解的催化速率常数(k cat)和二阶催化速率常数(k 2 cat = k cat / K M)。在的情况下,8:锌(II)2,的重复ķ
Intramolecular Arene Hydroxylation versus Intermolecular Olefin Epoxidation by (μ-η<sup>2</sup>:η<sup>2</sup>-Peroxo)dicopper(II) Complex Supported by Dinucleating Ligand
A discrete (mu-eta2:eta2-peroxo)Cu(II)2 complex, [Cu2(O2)(H-L)]2+, is capable of performing not only intramolecular hydroxylation of a m-xylyl linker of a dinucleatingligand but also intermolecular epoxidation of styrene via electrophilic reaction to the C=C bond and hydroxylation of THF by H-atom abstraction.