Herrera Juan Manuel, Bleuzen Anne, Dromzée Yves, Julve Miguel, Lloret Francesc, Verdaguer Michel
Laboratoire de Chimie Inorganique et Matériaux Moléculaires, Université Pierre et Marie Curie, Unité CNRS 7071, F-75252 Paris Cedex 05, France.
Inorg Chem. 2003 Nov 3;42(22):7052-9. doi: 10.1021/ic034188+.
The synthesis, X-ray structures, and magnetic behavior of two new, three-dimensional compounds W(IV)(mu-CN)(4)Co(II)(H(2)O)(2).4H(2)O (1) and W(V)(CN)(2)(mu-CN)(4)Co(II)(H(2)O)(2).4H(2)O (2) are presented. Compound 1 crystallizes in the tetragonal system, space group I4/m with cell constants a = b = 11.710(3) A, c = 13.003(2) A, and Z = 4, whereas 2 crystallizes in the orthorhombic system, space group Cmca with cell constants a = 13.543(5) A, b = 16.054(6) A, c = 15.6301(9) A, and Z = 4. The structure of 1 shows alternating eight-coordinated W(IV) and six-coordinated Co(II) ions bridged by single cyanides in a three-dimensional network. The geometry of each W(IV)(CN)(8) entity in 1 is close to a square antiprism. Its eight cyanide groups are coordinated to Co(II) ions which have two coordinated water molecules in trans position. The structure of 2 consists of alternating eight-coordinated W(V) and six-coordinated Co(II) ions linked by single cyanide bridges in a three-dimensional network. Each W(V)(CN)(8) unit shows a geometry close to a square antiprism. Only six of its eight cyanide groups are coordinated to Co(II) ions while the other two are terminal. The Co(II) ion in 2 has the same CoN(4)O(2) environment as in 1. The magnetic behavior of 1 is that of magnetically isolated high spin Co(II) ions (S(Co) = 3/2), bridged by the diamagnetic W(IV)(CN)(8) units (S(W(IV)) = 0). The magnetic behavior of 2, where the high spin Co(II) ions are bridged by the paramagnetic W(V)(CN)(8) units [S(W(V)) = 1/2], is that of ferromagnetically coupled Co(II) and W(V) giving rise to an ordered ferromagnetic phase below 18 K. The magnetic properties of 1 are used as a blank to extract the parameters that are useful to analyze the magnetic data of compound 2.
本文介绍了两种新型三维化合物[W(IV)[(μ-CN)₄Co(II)(H₂O)₂]₂·4H₂O]ₙ(1)和[[W(V)(CN)₂]₂[(μ-CN)₄Co(II)(H₂O)₂]₃·4H₂O]ₙ(2)的合成、X射线结构及磁行为。化合物1结晶于四方晶系，空间群为I4/m，晶胞参数a = b = 11.710(3) Å，c = 13.003(2) Å，Z = 4；而化合物2结晶于正交晶系，空间群为Cmca，晶胞参数a = 13.543(5) Å，b = 16.054(6) Å，c = 15.6301(9) Å，Z = 4。1的结构显示，八配位的W(IV)离子和六配位的Co(II)离子交替排列，由单个氰化物在三维网络中桥连。1中每个[W(IV)(CN)₈]⁴⁻实体的几何形状接近方形反棱柱。其八个氰化物基团与处于反位有两个配位水分子的Co(II)离子配位。2的结构由八配位的W(V)离子和六配位的Co(II)离子交替排列，通过单个氰化物桥连在三维网络中相连。每个[W(V)(CN)₈]³⁻单元的几何形状接近方形反棱柱。其八个氰化物基团中只有六个与Co(II)离子配位，另外两个为端基。2中的Co(II)离子具有与1中相同的CoN₄O₂环境。1的磁行为是由抗磁性的[W(IV)(CN)₈]³⁻单元(S(W(IV)) = 0)桥连的磁孤立高自旋Co(II)离子(S(Co) = 3/2)的磁行为。2的磁行为中，高自旋Co(II)离子由顺磁性的[W(V)(CN)₈]³⁻单元[S(W(V)) = 1/2]桥连，导致在18 K以下出现有序铁磁相。1的磁性性质被用作空白来提取对分析化合物2的磁数据有用的参数。
