New polynuclear manganese(II) complexes with orotic acid and some of its derivatives: crystal structures, spectroscopic and magnetic studies
作者:Fran�oise Nepveu、Nicolas Gaultier、Nikolaus Korber、Joel Jaud、Paule Castan
DOI:10.1039/dt9950004005
日期:——
Three polynuclear manganese(II) complexes containing orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H3L1) or one of its substituted derivatives [3-methyl-(H2L2) or 5-nitro-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid (H3L1)] have been synthesized and characterized by X-ray crystallography, UV/VIS and magnetic susceptibility measurements. Complex 1 consists of neutral
三种含有核果酸(2,6-二氧-1,2,3,6-四氢嘧啶-4-羧酸,H 3 L 1)或其取代衍生物之一的多核锰(II)配合物[3-甲基-(H合成了2 L 2)或5-硝基-2,6-二氧-1,2,3,6-四氢嘧啶-4-羧酸(H 3 L 1)],并通过X射线晶体学,UV / VIS进行了表征和磁化率测量。配合物1由中性[Mn 2(HL 1)2(H 2 O)6 ]单元组成,它们沿z方向形成聚合物链轴在单元格中的Mn(1)⋯Mn(2)距离为5.628(1)Å,而链中的Mn(2)⋯Mn(2)距离为4.715(1)Å。配合物2的每个晶胞包含一个中性的中心对称二聚体[Mn 2(L 2)2(H 2 O)6 ],其中的Mn⋯Mn距离短[3.472(2)Å],并且存在反铁磁交换相互作用。根据汉密尔顿方程H = –2 JS 1 S 2得出的磁化率方程拟合实验数据,得到交换参数J = –1.3 cm –1和g = 1