Three complexes of model nucleobases with exocyclic oxygen atoms (1-methyluracilate, mura; 1-methylcytosine, mcyt; 9-methylguanine, Hmgua) which contain PtII bonded to a ring N atom and an alkali metal ion (Cs+, K+, Na+) bonded to a keto oxygen of the bases, trans-Cs[Pt(NH3)(mura)I2]·4H2O 1, trans-K[Pt(NH3)2(mcyt)2][PF6]3·H2O 2, and trans-[Pt(NH3)(Hmgua)2(mcyt)Na(H2O)2][ClO4]3·0.5H2O 3, have been prepared and their crystal structures determined. The compounds have been studied, among others, with regard to the role of alkali metal ions for the rotation of nucleobases when bound to PtII. While in the case of 1 the alkali metal ion is necessary for charge compensation and for this reason its binding to the platinated mura is not fully unexpected, it is surprising to see that alkali metal ions even bind to cationic complexes of PtII containing neutral nucleobases (2, 3).
三种带有外环氧原子的核碱基模型复合物(1-甲基尿
嘧啶,mura;1-甲基
胞嘧啶,mcyt;9-甲基
鸟嘌呤,Hmgua),它们含有与环 N 原子结合的 PtII 和与碱基酮氧结合的碱
金属离子(Cs+、K+、Na+)、反式-Cs[Pt(NH3)(mura)I2]-4 1、反式-K[Pt(NH3)2(mcyt)2][PF6]3-
H2O 2 和反式-[Pt(NH3)(Hmgua)2(mcyt)Na( )2][ClO4]3-0。5 3,并确定了它们的晶体结构。对这些化合物进行了研究,其中包括碱
金属离子与 PtII 结合时对核碱基旋转的作用。在 1 的情况中,碱
金属离子是电荷补偿所必需的,因此它与镀
铂缪拉的结合并不完全出乎意料,但令人惊讶的是,碱
金属离子甚至与含有中性核碱基的 PtII 阳离子复合物结合(2,3)。