Inorg Chem. 2018 Jul 2;57(13):7757-7762. doi: 10.1021/acs.inorgchem.8b00812. Epub 2018 Jun 15.
By utilizing the quinolinic derivative, 8-carboxymethoxy-2-carboxylicquinoline (L), five transition metal coordination complexes, [M(L)(HO)]·HO] (M = Mn (1), Co (2)), [Ni(L)(HO)] (3), and {M(L)} (M = Ni (4), Cu (5)), were synthesized by hydrothermal methods employing similar synthetic strategies. The crystal structures, magnetism and high-field EPR were characterized for the obtained compounds. 1-3 are mononuclear compounds. 1 and 2 have pentagonal bipyramidal geometry, while 4 and 5 exhibit one-dimensional zig-zag chain. Direct current magnetic and EPR studies demonstrate that compound 2 has large and positive D value (∼70.4 cm), indicating the easy plane magnetic anisotropies of 2. This D value is the largest one in the reported Co(II) complexes with pentagonal bipyramidal geometry. Field-induced slow magnetic relaxation behavior was observed for 2 by the dynamic ac magnetic susceptibility measurements. The dc magnetic susceptibility studies of 4 and 5 give similar weak M-M antiferromagnetic interactions ( J = -1.50 and -3.55 K for 4 and 5, respectively). High-field EPR results show that 4 can be considered as a quantum antiferromagnet.
利用喹啉衍生物 8-羧甲氧基-2-羧酸喹啉（L），通过水热方法合成了五个过渡金属配位化合物，[M(L)(HO)]·HO]（M = Mn（1），Co（2）），[Ni(L)(HO)]（3）和{M(L)}（M = Ni（4），Cu（5）），采用相似的合成策略。对所得化合物进行了晶体结构、磁性和高场 EPR 表征。1-3 是单核化合物。1 和 2 具有五重锥形几何形状，而 4 和 5 则呈现一维之字形链。直流磁和 EPR 研究表明，化合物 2 具有较大的正值 D 值（约 70.4 cm），表明 2 具有易面磁各向异性。该 D 值是报道的具有五重锥形几何形状的 Co(II)配合物中最大的一个。通过动态交流磁化率测量观察到 2 具有场诱导的缓慢磁弛豫行为。4 和 5 的直流磁化率研究给出了相似的弱 M-M 反铁磁相互作用（对于 4 和 5，分别为 J = -1.50 和 -3.55 K）。高场 EPR 结果表明，4 可被视为量子反铁磁体。
