Kalita Pankaj, Goura Joydeb, Herrera Juan Manuel, Colacio Enrique, Chandrasekhar Vadapalli
School of Chemical Sciences, National Institute of Science Education and Research, Homi Bhabha National Institute, Jatni, Khurda, Bhubaneswar 752050, Odisha, India.
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
ACS Omega. 2018 May 14;3(5):5202-5211. doi: 10.1021/acsomega.8b00292. eCollection 2018 May 31.
The reaction of 2-methoxy-6-[{2-(2-hydroxyethylamino)ethylimino}methyl] phenol (LH) with lanthanide metal salts followed by the addition of nickel acetate allowed isolation of a family of octanuclear complexes, [NiLn(μ-OH)(μ-OH)(μ-OOCCH)(LH)]·(OH)·HO. Single crystal X-ray diffraction studies of these complexes reveal that their central metallic core consists of two tetranuclear [NiLnO] cubane subunits fused together by acetate and hydroxide bridges. The magnetic study of these complexes reveals a ferromagnetic interaction between the Ln and the Ni center. The magnitude of exchange coupling between the Ni and Ln center, parametrized from the magnetic data of the Gd analogue, gives = +0.86 cm. The magneto caloric effect, studied for the Ni Gd complex, shows a maximum of magnetic entropy change, -Δ = 22.58 J kg K at 3 K for an applied external field of 5 T.
2-甲氧基-6-[{2-(2-羟乙基氨基)乙基亚氨基}甲基]苯酚（LH）与镧系金属盐反应，随后加入醋酸镍，得到了一系列八核配合物，[NiLn(μ-OH)(μ-OH)(μ-OOCCH)(LH)]·(OH)·H₂O。对这些配合物进行单晶X射线衍射研究表明，它们的中心金属核由两个四核[NiLnO]立方烷亚基通过醋酸根和氢氧根桥连接在一起组成。对这些配合物的磁性研究表明，Ln和Ni中心之间存在铁磁相互作用。根据Gd类似物的磁性数据确定的Ni和Ln中心之间的交换耦合强度为J = +0.86 cm⁻¹。对Ni-Gd配合物研究的磁热效应表明，在5 T的外加磁场下，3 K时磁熵变的最大值为-ΔSm = 22.58 J kg⁻¹ K⁻¹。
