Syntheses, crystal structures and magnetic properties of two Ni-4(mu(3)-phenoxido)(4) cubanes: Role of additional bridging carboxylates
Syntheses, crystal structures and magnetic properties of two Ni-4(mu(3)-phenoxido)(4) cubanes: Role of additional bridging carboxylates
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两种 Ni-4(mu(3)-phenoxydo)(4) 古巴烷的合成、晶体结构和磁性：额外桥连羧酸盐的作用
DOI：
10.1016/j.poly.2017.03.039
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发表时间：
2017
期刊：
影响因子：
2.6
通讯作者：
Mohanta Sasankasekhar
中科院分区：
文献类型：
--
作者：
M;al Leena;Ghosh Sagar;Liu Cai-Ming;Mohanta Sasankasekhar
本文报道了它的合成、晶体结构、电喷雾质谱两种Ni_4 O_4立方烷化合物[Ni_（III）_4L_2]的（正）和变温变场磁性（µ 1，3-HCO 2）2]（ClO 4）2·2 H2O（1）和[NiII 4L 2（µ 1，3-o-ClPhCO 2）2]（ClO 4）2·3 H2O（2）衍生自Robson型四亚氨基二酚大环配体H2 L（4-乙基-2，6-二甲酰基苯酚和2，2-二甲基-1，3-丙二胺的2 + 2缩合反应）。畸变立方烷的四个氧原子都是酚氧氧原子，来自两个去质子化的大环[L]2-，即，这些化合物是Ni_4（μ_3-phenoxido）_4立方烷。在立方体的两个相对面中的两对中的每一对中的镍（II）中心另外由顺式羧酸盐、甲酸盐in 1和氯苯甲酸盐in 2桥接。变温和变场磁化强度数据揭示了1和2中的整体反铁磁相互作用，其中六个路径中的两个是铁磁的（4.06 cm− 1 in 1和1.58 cm− 1 in 2），其余四个路径是反铁磁的（−3.03 cm− 1 in 1和−1.55 cm− 1 in 2）。讨论了α J与NiIII-O（phenoxo）-Ni Ⅱ角关联的可能性以及羧酸根结构和第一激发态与基态能量差对磁性的影响。
The work in the present investigation reports the syntheses, crystal structures, ESI-MS (positive) and variable-temperature and variable-field magnetic properties of two Ni4O4cubane compounds of composition [NiII4L2(µ1,3-HCO2)2](ClO4)2·2H2O (1) and [NiII4L2(µ1,3-o-ClPhCO2)2](ClO4)2·3H2O (2) derived from the Robson type tetraiminodiphenol macrocyclic ligand H2L (2 + 2 condensation of 4-ethyl-2,6-diformylphenol and 2,2-dimethyl-1,3-diaminopropane). All the four oxygen atoms of the distorted cubane are phenoxido oxygen atoms, coming from two deprotonated macrocycle, [L]2−, i.e., these compounds are Ni4(μ3–phenoxido)4cubanes. The nickel(II) centers in each of the two pairs in two opposite faces of the cube are additionally bridged by a syn–syn carboxylate, formate in1ando-chlorobenzoate in2. Variable-temperature and variable-field magnetization data reveal an overall antiferromagnetic interaction in both1and2, where two of the six pathways are ferromagnetic (4.06 cm−1in1and 1.58 cm−1in2) and the remaining four pathways are antiferromagnetic (−3.03 cm−1in1and −1.55 cm−1in2). The possibility of aJversus NiII–O(phenoxo)–NiIIangle correlation and the roles of carboxylate moiety as well as energy difference between the first excited state and ground state on magnetic properties have been discussed.