Przychodzeń Paweł, Lewiński Krzysztof, Bałanda Maria, Pełka Robert, Rams Michał, Wasiutyński Tadeusz, Guyard-Duhayon Carine, Sieklucka Barbara
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
Inorg Chem. 2004 May 3;43(9):2967-74. doi: 10.1021/ic035464n.
The syntheses, X-ray structures, and magnetic behaviors of two new cyano-bridged assemblies, the molecular [Mn(III)(salen)H2O]3[W(V)(CN)8].H2O (1) and one-dimensional [Mn(salen)(H2O)2]2[[Mn(salen)(H2O)][Mn(salen)]2[Mo(CN)(8)]].0.5ClO4.0.5OH.4.5H2O (2), are presented. Compound 1 crystallizes in the monoclinic system, has space group P2(1)/c, and has unit cell constants a = 13.7210(2) A, b = 20.6840(4) A, c = 20.6370(2) A, and Z = 4. Compound 2 crystallizes in the triclinic system, has space group P, and has unit cell dimensions a = 18.428(4) A, b = 18.521(3) A, c = 18.567(4) A, and Z = 2. The structure of 1 consists of the asymmetric V-shaped Mn-NC-W-NC-Mn-O(phenolate)-Mn molecules, where W(V) coordinates with [Mn(salen)H2O] and singly phenolate-bridged [Mn(salen)H2O]2 moieties through the neighboring cyano bridges. The [W(V)(CN)8]3- ion displays distorted square-antiprism geometry. The structure of 2 consists of the cyano-bridged [Mn3(III)Mo(IV)]n- repeating units linked by double phenolate bridges into one-dimensional zigzag chains. The Mn(III) centers are bound to Mo(IV) of square-antiprism geometry through the neighboring cyano bridges. The magnetic studies of 1 reveal the antiferromagnetic intramolecular interactions through the CN and phenolate bridges and the relatively weak intermolecular interactions. Compound 1 becomes antiferromagnetically ordered below TN = 4.6 K. The presence of the magnetic anisotropy is documented with the MH measurements carried out for both polycrystalline and single-crystal samples. At T = 1.9 K, the spin-flop transition is observed in the field of 18 kOe applied parallel to the bc plane, which is the easy plane of magnetization. Field dependence of magnetization of 1 shows field-induced metamagnetic behavior from the antiferromagnetic ground state of ST = 3/2 to the state of ST = 5/2. The magnetic properties of 2 indicate a weak antiferromagnetic interaction between Mn(III) centers in double-phenolate-bridged [Mn(III)(salen)]2 dinuclear subunits and a very weak ferromagnetic interaction between them through the diamagnetic [Mo(IV)(CN)8]4- spacer.
本文报道了两种新型氰基桥联配合物的合成、X射线结构和磁行为，分别为分子型的[Mn(III)(salen)H₂O]₃[W(V)(CN)₈]·H₂O (1)和一维的[Mn(salen)(H₂O)₂]₂[[Mn(salen)(H₂O)][Mn(salen)]₂[Mo(CN)₈]].0.5ClO₄.0.5OH.4.5H₂O (2)。化合物1结晶于单斜晶系，空间群为P2(1)/c，晶胞参数a = 13.7210(2) Å，b = 20.6840(4) Å，c = 20.6370(2) Å，Z = 4。化合物2结晶于三斜晶系，空间群为P，晶胞参数a = 18.428(4) Å，b = 18.521(3) Å，c = 18.567(4) Å，Z = 2。1的结构由不对称的V形Mn-NC-W-NC-Mn-O(酚盐)-Mn分子组成，其中W(V)通过相邻的氰基桥与[Mn(salen)H₂O]和单酚盐桥联的[Mn(salen)H₂O]₂部分配位。[W(V)(CN)₈]³⁻离子呈现扭曲的四方反棱柱几何构型。2的结构由氰基桥联的[Mn₃(III)Mo(IV)]ₙ重复单元通过双酚盐桥连接成一维锯齿链。Mn(III)中心通过相邻的氰基桥与四方反棱柱几何构型的Mo(IV)相连。对1的磁性研究揭示了通过CN和酚盐桥的反铁磁分子内相互作用以及相对较弱的分子间相互作用。化合物1在TN = 4.6 K以下变为反铁磁有序。对多晶和单晶样品进行的MH测量证明了磁各向异性的存在。在T = 1.9 K时，在平行于bc平面（即易磁化平面）施加的18 kOe磁场中观察到自旋翻转转变。1的磁化强度与磁场的关系表明从ST = 3/2的反铁磁基态到ST = 5/2的态存在场诱导的变磁行为。2的磁性性质表明在双酚盐桥联的[Mn(III)(salen)]₂双核亚基中的Mn(III)中心之间存在弱的反铁磁相互作用，并且通过抗磁性的[Mo(IV)(CN)₈]⁴⁻间隔基它们之间存在非常弱的铁磁相互作用。
