Yuste C, Armentano D, Marino N, Cañadillas-Delgado L, Delgado F S, Ruiz-Pérez C, Rillema D P, Lloret F, Julve M
Instituto de Ciencia Molecular (ICMol)/Departament de Química Inorgànica, Universitat de València, Polígono La Coma s/n, E-46980, Paterna, València, Spain.
Dalton Trans. 2008 Mar 28(12):1583-96. doi: 10.1039/b717347d. Epub 2008 Feb 26.
The preparation, crystal structures and magnetic properties of the copper(II) complexes of formula Cu(pyim)(tcm)(2) (1), Cu(bpy)(tcm)(2) (2), [Cu(4)(bpz)(4)(tcm)(8)] (3), {[Cu(terpy)(tcm)].tcm}(n) (4) and {[Cu(2)(tppz)(tcm)(4)].3/2H(2)O}(n) (5) [pyim = 2-(2-pyridyl)imidazole, tcm = tricyanomethanide, bpy = 2,2'-bipyridine, bpz = 2,2'-bipyrazine, terpy = 2,2':6',2''-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine] are reported. Complexes, 1, 2 and 4 are uniform copper(II) chains with single- (1 and 4) and double-(2) micro-1,5-tcm bridges with values of the intrachain copper-copper separation of 7.489(1) (1), 7.520(1) and 7.758(1) (2) and 7.469(1) A (4). Each copper atom in 1, 2 and 4 is five-coordinate with bidentate pyim (1)/bpy (2) and tridentate terpy (4) ligands and nitrile-nitrogen atoms from bridging (1,2 and 4) and terminal (1) tcm groups building a distorted square pyramidal surrounding. The structure of 3 is made up of neutral centrosymmetric rectangles of (2,2'-bipyrazine)copper(II) units at the corners, the edges being built by single- and double-micro-1,5-tcm bridges with copper-copper separations of 7.969(1) and 7.270(1) A, respectively. Five- and six-coordinated copper atoms with distorted square pyramidal and elongated octahedral environments occur in . Compound 5 is a neutral copper(II) chain with regular alternating bis-tridentate tppz and double micro-1,5-tcm bridges, the intrachain copper-copper distances being 6.549(7) and 7.668(1) A, respectively. The two crystallographically independent copper atoms in 5 have an elongated octahedral geometry with three tppz nitrogen atoms and a nitrile-nitrogen atom from a bridging tcm group in the equatorial positions, and two nitrile nitrogen atoms from a terminal and a bridging tcm ligand occupying the axial sites. The investigation of the magnetic properies of 1-5 in the temperature range 1.9-295 K has shown the occurrence of weak ferro- [J = +0.11(1) cm(-1) (2)] and antiferromagnetic interactions [J = -0.093(1) (1), -0.083(1) (4), -0.04(1) and 1.21(1) cm(-1) (3)] across the micro-1,5-tcm bridges and intermediate antiferromagnetic coupling [-J = 37.4(1) cm(-1) (5)] through bis-tridentate tppz. The values of the magnetic interactions are analyzed through simple orbital symmetry considerations and compared with those previously reported for related systems.
报道了式为Cu(pyim)(tcm)(2) (1)、Cu(bpy)(tcm)(2) (2)、[Cu(4)(bpz)(4)(tcm)(8)] (3)、{[Cu(terpy)(tcm)].tcm}(n) (4)和{[Cu(2)(tppz)(tcm)(4)].3/2H(2)O}(n) (5)的铜(II)配合物的制备、晶体结构和磁性[pyim = 2-(2-吡啶基)咪唑，tcm = 三氰基甲烷化物，bpy = 2,2'-联吡啶，bpz = 2,2'-联吡嗪，terpy = 2,2':6',2''-三联吡啶，tppz = 2,3,5,6-四(2-吡啶基)吡嗪]。配合物1、2和4是均匀的铜(II)链，具有单-(1和4)和双-(2)μ-1,5-tcm桥，链内铜-铜间距分别为7.489(1) (1)、7.520(1)和7.758(1) (2)以及7.469(1) Å (4)。1、2和4中的每个铜原子与双齿pyim (1)/bpy (2)和三齿terpy (4)配体以及来自桥连(1、2和4)和末端(1) tcm基团的腈氮原子五配位，形成扭曲的四方锥环境。3的结构由位于角上的(2,2'-联吡嗪)铜(II)单元的中性中心对称矩形组成，边由单和双μ-1,5-tcm桥构建，铜-铜间距分别为7.969(1)和7.270(1) Å。中出现了具有扭曲四方锥和拉长八面体环境的五配位和六配位铜原子。化合物5是具有规则交替的双三齿tppz和双μ-1,5-tcm桥的中性铜(II)链，链内铜-铜距离分别为6.549(7)和7.668(1) Å。5中两个晶体学独立的铜原子具有拉长的八面体几何结构，三个tppz氮原子和来自桥连tcm基团的一个腈氮原子位于赤道位置，一个末端和一个桥连tcm配体的两个腈氮原子占据轴向位置。对1-5在1.9-295 K温度范围内的磁性研究表明，通过μ-1,5-tcm桥发生了弱铁磁相互作用[J = +0.11(1) cm(-1) (2)]和反铁磁相互作用[J = -0.093(1) (1)、-0.083(1) (4)、-0.04(1)和1.21(1) cm(-1) (3)]，以及通过双三齿tppz发生了中间反铁磁耦合[-J = 37.4(1) cm(-1) (5)]。通过简单的轨道对称性考虑分析了磁相互作用的值，并与先前报道的相关体系的值进行了比较。
