Colacio Enrique, Domínguez-Vera José M, Lloret Francesc, Moreno Sánchez José M, Kivekäs Raikko, Rodríguez Antonio, Sillanpää Reijo
Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
Inorg Chem. 2003 Jun 30;42(13):4209-14. doi: 10.1021/ic034155u.
The hydrothermal reaction of K(3)[Fe(CN)(6)], CuCl(2), and 2,2'-bipyridine (bipy) resulted in the formation of a 2D cyanide-bridged heterobimetallic Fe(II)-Cu(I) complex, [Fe(bipy)(2)(CN)(4)Cu(2)], 1. Working in the same conditions, but using 2,2'-bipyrimidine (bpym) instead of bipy and methanol as solvent, we obtained the homometallic Cu(I) complex Cu(2)(CN)(2)(bpym), 2. The structure of 1 consists of cyanide-bridged Fe(II)-Cu(I) layers, constructed from alternately fused 6 (Fe(2)Cu(4)) and 10 (Fe(2)Cu(8)) metal-membered centrosymmetric rings, in which copper(I) and iron(II) ions exhibit distorted trigonal planar and octahedral cooordination environments, respectively. The formation of 1 can be explained by assuming that, under high pressure and temperature, iron(III) and copper(II) ions are reduced with the simultaneous and/or subsequent substitution of four cyanide ligands by two bipy molecules in the ferricyanide anions. It is interesting to note that 1 is the first cyanide-bridged heterobimetallic complex prepared by solvothermal methods. The structure of 2 consists of neutral 2D honeycomb layers constructed from fused Cu(6)(CN)(4)(bpym)(2) rings, in which copper(I) atoms exhibit distorted tetrahedral geometry. The isolation of 1 and 2, by using K(3)[Fe(CN)(6)] as starting material, demonstrates that hydrothermal chemistry can be used not only to prepare homometallic materials but also to prepare cyanide-bridged bimetallic materials. The temperature dependence of chi(M)T and Mössbauer measurements for 1 reveal the existence of a high spin <--> low spin equilibrium involving the Fe(II) ions.
K(3)[Fe(CN)(6)]、CuCl(2) 与 2,2'-联吡啶(bipy)发生水热反应,生成了二维氰基桥联异金属 Fe(II)-Cu(I) 配合物 [Fe(bipy)(2)(CN)(4)Cu(2)],即 1。在相同条件下工作,但使用 2,2'-联嘧啶(bpym)代替 bipy 并以甲醇为溶剂,我们得到了同金属 Cu(I) 配合物 Cu(2)(CN)(2)(bpym),即 2。1 的结构由氰基桥联的 Fe(II)-Cu(I) 层组成,该层由交替稠合的 6 元(Fe(2)Cu(4))和 10 元(Fe(2)Cu(8))金属中心对称环构建而成,其中铜(I) 和铁(II) 离子分别呈现扭曲的三角平面和八面体配位环境。1 的形成可以通过假设在高压和高温下,铁(III) 和铜(II) 离子被还原,同时和/或随后在铁氰根阴离子中两个 bipy 分子取代四个氰基配体来解释。值得注意的是,1 是通过溶剂热法制备的首个氰基桥联异金属配合物。2 的结构由由稠合的 Cu(6)(CN)(4)(bpym)(2) 环构建而成的中性二维蜂窝层组成,其中铜(I) 原子呈现扭曲的四面体几何形状。以 K(3)[Fe(CN)(6)] 为起始原料分离得到 1 和 2,表明水热化学不仅可用于制备同金属材料,还可用于制备氰基桥联双金属材料。1 的 χ(M)T 和穆斯堡尔测量的温度依赖性揭示了涉及 Fe(II) 离子的高自旋⇄低自旋平衡的存在。