Cooperativity between Metal Ions in the Cleavage of Phosphate Diesters and RNA by Dinuclear Zn(II) Catalysts
作者:Olga Iranzo、Terry Elmer、John P. Richard、Janet R. Morrow
DOI:10.1021/ic030131b
日期:2003.12.1
titration of these ligands with Zn(NO(3))(2) was monitored by (1)H NMR. Each ligand was found to bind two Zn(II) ions with a very high affinity at near neutral pH under conditions of millimolar ligand and 2 equiv of Zn(NO(3))(2). In contrast, a stable mononuclear complex was formed in solutions containing 5.0 mM L2OH and 1 equiv of Zn(NO(3))(2). (1)H and (13)C NMR spectral data are consistent with formation
研究了一系列含有连接的1,4,7-三氮杂环壬烷大环的配体,以制备包括1,3-双(1,4,7-三氮杂环酮-1-基)-2-羟基丙烷( L2OH),1,5-双(1,4,7-三氮杂环壬-1-基)戊烷(L3),2,9-双(1-甲基-1,4,7-三氮杂环壬-1-基)-1 ,10-菲咯啉(L4)和α,α'-双(1,4,7-三氮杂环壬-1-基)-间二甲苯(L5)。通过(1)H NMR监测这些配体与Zn(NO(3))(2)的滴定。发现每个配体在毫摩尔配体和2当量的Zn(NO(3))(2)的条件下,在接近中性pH的条件下以很高的亲和力结合两个Zn(II)离子。相反,在含有5.0 mM L2OH和1当量的Zn(NO(3))(2)的溶液中形成了稳定的单核络合物。(1)H和(13)C NMR光谱数据与高度对称的单核络合物Zn(L2OH)的形成一致,其中Zn(II)离子夹在两个三氮杂环壬烷单元之间。在Zn(2)(L2O)催化下于pH