Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai, 200062, China.
Dalton Trans. 2011 Dec 21;40(47):12742-9. doi: 10.1039/c1dt11068c. Epub 2011 Oct 19.
Two isomorphous Co(II) and Ni(II) coordination polymers with azide and the 4-(4-pyridyl)benzoic acid N-oxide ligand (4,4-Hopybz) were synthesized, and structurally and magnetically characterized. They are formulated as M(4,4-opybz)(N(3))(H(2)O) (M = Co, 1 and Ni, 2). The compounds consist of 2D coordination networks, in which 1D coordination chains with (μ-N(3))(μ-COO) bridges are interlinked by the 4,4-opybz spacers, and the structure also features intra- and interchain O-HO hydrogen-bonding bridges between metal ions. Both compounds exhibit ferromagnetic interactions through the intrachain (μ-N(3))(μ-COO)(O-HO) bridges and antiferromagnetic interactions through the interchain O-HO bridges. The ferromagnetic chains are antiferromagnetically ordered, and the antiferromagnetic phases exhibit field-induced metamagnetic transition. It is found that 1 displays slow relaxation of magnetization, typical of single-chain magnets, while 2 does not. The difference emphasizes the great importance of large magnetic anisotropy for single-chain-magnet dynamics.
合成了两种同构的 Co(II)和 Ni(II)配位聚合物，它们含有叠氮化物和 4-(4-吡啶基)苯甲酸 N-氧化物配体(4,4-Hopybz)，并对其进行了结构和磁性表征。它们的化学式为M(4,4-opybz)(N(3))(H(2)O) (M = Co, 1 和 Ni, 2)。这些化合物由二维配位网络组成，其中一维配位链通过(μ-N(3))(μ-COO)桥相互连接，4,4-opybz 间隔物，结构还具有金属离子之间的内链和链间 O-HO 氢键桥。两种化合物均通过链内(μ-N(3))(μ-COO)(O-HO)桥表现出铁磁相互作用，通过链间 O-HO 桥表现出反铁磁相互作用。铁磁链呈反铁磁有序，反铁磁相表现出场诱导的变磁转变。发现 1 表现出典型的单链磁体的磁化缓慢弛豫，而 2 则没有。这种差异强调了大磁各向异性对单链磁体动力学的重要性。
