Complexes with the ligand 4,6-dimethyl-1,2,3-triazolo-[4,5-d]-pyrimidin-5,7-dionato (dmax−) and the auxiliary chelating-bridging ligand bipyrimidine (bpym) have been synthesized and structurally characterized for the divalent cations of Zn, Cd and Cu. For Zn and Cd, dinuclear complexes with the formulae [Zn2(dmax)4(H2O)2(bpym)]·2H2O and [Cd2(dmax)4(H2O)4(bpym)]·6H2O have been isolated whereas for Cu, the one-dimensional polymer [Cu2(dmax)4(bpym)]·5H2O}n has been obtained. Bpym acts as a chelating-bridging ligand in the three compounds, joining couples of metal ions. Two crystallographically and chemically different dmax− ligands are present in each of these complexes, one monodentately linked via the triazole N atom furthest from the pyrimidine ring (N2) and the other either monodentately linked via the triazole N atom closer to a carbonyl group (N1, Zn and Cd compounds) or in bridging N1-N2 mode (Cu compound), in the latter case generating an one-dimensional polymer with alternating bpym and (dmax)2 bridges. The magnetic interaction across the bpym bridge gives rise to a strong antiferromagnetic interaction (2J = −201 cm−1), whereas that across the (dmax)2 bridge is negligible and cannot be reliably determined (obscured by the strong one). The hydrogen bonds between water molecules and the triazolopyrimidine derivative build the 3-D structure of the compounds.
与
配体 4,6-二甲基-
1,2,3-三唑并-[4,5-d]-
嘧啶-5,7-二酮 (dmax−) 和辅助螯合桥
配体联
嘧啶 (bpym) 的配合物已被Zn、Cd 和 Cu 的二价阳离子的合成和结构表征。对于 Zn 和 Cd,已分离出分子式为 [Zn2(dmax)4(
H2O)2(bpym)]·2 和 [Cd2(dmax)4( )4(bpym)]·6 的双核配合物,而对于 Cu,得到一维聚合物[Cu2(dmax)4(bpym)]·5 }n。 Bpym 在这三种化合物中充当螯合桥
配体,连接
金属离子对。这些配合物中的每一个中都存在两个晶体学和
化学上不同的 dmax−
配体,一个通过距
嘧啶环最远的三唑 N 原子 (N2) 单齿连接,另一个通过更靠近羰基的三唑 N 原子单齿连接 (N1 ,Zn 和 Cd 化合物)或桥接 N1-N2 模式(Cu 化合物),在后一种情况下生成具有交替 bpym 和 (dmax)2 桥的一维聚合物。 bpym 桥上的磁相互作用产生强反
铁磁相互作用 (2J = −201 cm−1),而 (dmax)2 桥上的磁相互作用可以忽略不计,无法可靠确定(被强磁相互作用掩盖)。
水分子和三唑并
嘧啶衍
生物之间的氢键构建了化合物的三维结构。