Metal Coordination and Imine−Amine Hydrogen Bonding as the Source of Strongly Shifted Adenine p<i>K</i><sub>a</sub> Values
作者:Michael Roitzsch、Bernhard Lippert
DOI:10.1021/ja038834f
日期:2004.3.3
crystal structure of a Pt(II) complex of composition trans-[(NH(3))(2)Pt(1,9-DimeA) (1,9-DimeAH)](ClO(4))(3) (2) with 1,9-DimeA = 1,9-dimethyladenine and 1,9-DimeAH(+) = 1,9-dimethyladeninium) is presented. Complex 2 forms upon deprotonation of one of the exocyclic amino groups of the adeninium ligands in trans-[(NH(3))(2)Pt(1,9-DimeAH)(2)](ClO(4))(4) (1), where the two nucleobases are in a head-tail arrangement
组成反式-[(NH(3))(2)Pt(1,9-DimeA) (1,9-DimeAH)](ClO(4))( 3) (2) 1,9-DimeA = 1,9-二甲基腺嘌呤和 1,9-DimeAH(+) = 1,9-二甲基腺嘌呤)。复合物 2 在反式-[(NH(3))(2)Pt(1,9-DimeAH)(2)](ClO(4))(4) 中腺嘌呤配体的环外氨基之一脱质子化后形成(1),其中两个核碱基处于头尾排列。1 (4.1 +/- 0.2) 的低 pK(a1) 是金属配位对嘌呤碱 N7 的影响和去质子化物种的有效稳定相结合的结果。这一特征得到了 2 结构测定结果的支持,该结果显示了两个碱基的头-头取向以及 1,9-DimeA 的亚胺基团和 1,9-DimeAH 的氨基基团之间的分子内氢键. 在完全去质子化的物种 trans-[(NH(3))(2)Pt(1,9-DimeA)(2)](ClO(4))(2)