Laboratoire National des Champs Magnétiques Intenses, UPR CNRS 3228, 25 rue des Martyrs, B.P. 166, 38042 Grenoble Cedex 9, France.
Dalton Trans. 2013 Apr 7;42(13):4704-13. doi: 10.1039/c3dt32770a.
A series of six isostructural heterometallic trinuclear oxalate-bridged complexes of the formula (TDbenz)(2)(TsO)(2)[M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)]·6H(2)O·2CH(3)OH (TDbenz = 1,3,5-tris[2-(1,3-diazolinium)]benzene; TsO = 4-methylbenzenesulfonate; ox = oxalate; M(III) = Fe, M(II) = Mn (1), Fe (2), Co (3); M(III) = Cr, M(II) = Mn (4), Fe (5), Co (6)) have been synthesized from (NH(4))(3)[M(III)(ox)(3)]·3H(2)O, the chloride salts of the divalent metal ions and the tosylate salt of 1,3,5-tris[2-(1,3-diazolinium)]benzene (trisamidinium). Whereas the crystal structures of compounds 2, 3, 4 and 5 have been investigated by single-crystal X-ray diffraction, the structures of 1 and 6 have been checked by X-ray powder diffraction. All six compounds are isostructural and crystallise in the P1 space group. The crystals are composed of discrete linear M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2) trinuclear bimetallic units, trisamidinium and tosylate ions and solvent molecules. The linear trinuclear unit is based on a central trans-diaquametal(II) entity connected to two M(III)(ox)(3) (M(III) = Cr(III), Fe(III)) moieties through oxalate bridges. The divalent metal ions, surrounded by six oxygen atoms, adopt a distorted octahedral coordination geometry. The coordination sphere is composed of four oxygen atoms belonging to two oxalate ligands and two trans-coordinated water molecules. One of the oxalate ions is coordinated to the central metal centre whereas the other two oxalate ligands are non-bridging. In the crystal, intermolecular hydrogen bonds involving oxalate ligands, solvent molecules and the counter-ions form a complex 3D network. Variable-temperature magnetic susceptibility measurements indicate an antiferromagnetic interaction between the iron(III) and the metal(II) ions (J = -4.23, -6.73, -8.97 cm(-1) for 1, 2 and 3 respectively) whereas this interaction is ferromagnetic when iron(III) is replaced by chromium(III) (J = +1.21, +2.20, +3.63 cm(-1) for 4, 5 and 6 respectively). Moreover, the cobalt(II) derivatives exhibit high D values (D = 29.3 cm(-1) for and D = 27.4 cm(-1) for 6).
一系列六个同构的异金属三核草酸盐桥联配合物，化学式为(TDbenz)(2)(TsO)(2)[M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)]·6H(2)O·2CH(3)OH(TDbenz=1,3,5-三[2-(1,3-二氮杂环丁烷)]苯;TsO=4-甲基苯磺酸盐;ox=草酸盐;M(III)=Fe,M(II)=Mn(1),Fe(2),Co(3);M(III)=Cr,M(II)=Mn(4),Fe(5),Co(6))是由(NH(4))(3)[M(III)(ox)(3)]·3H(2)O、二价金属离子的氯化物盐和 1,3,5-三[2-(1,3-二氮杂环丁烷)]苯的tosylate盐(trisamidinium)合成的。化合物 2、3、4 和 5 的晶体结构已经通过单晶 X 射线衍射进行了研究，而 1 和 6 的结构则通过 X 射线粉末衍射进行了检查。所有六个化合物都是同构的，结晶于 P1 空间群。晶体由离散的线性M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)三核双金属单元、trisamidinium 和 tosylate 离子和溶剂分子组成。线性三核单元基于一个中央反式二价金属实体，通过草酸盐桥与两个M(III)(ox)(3)（M(III)=Cr(III)，Fe(III))部分连接。二价金属离子，被六个氧原子包围，采用扭曲的八面体配位几何形状。配位球由四个氧原子组成，属于两个草酸盐配体和两个反式配位的水分子。一个草酸盐离子与中心金属中心配位，而另外两个草酸盐配体是非桥联的。在晶体中，涉及草酸盐配体、溶剂分子和抗衡离子的分子间氢键形成了一个复杂的 3D 网络。变温磁化率测量表明，铁(III)和金属(II)离子之间存在反铁磁相互作用（J=-4.23、-6.73、-8.97cm(-1)分别对应于 1、2 和 3），而当铁(III)被铬(III)取代时，这种相互作用是铁磁的（J=+1.21、+2.20、+3.63cm(-1)分别对应于 4、5 和 6）。此外，钴(II)衍生物表现出高的 D 值（D=29.3cm(-1)和 D=27.4cm(-1)分别对应于 6）。
