Structures and magnetism of {Ni3}, {Ni9}, {Ni5} and {Ni12} mercapto-tetrazole based clusters

• Published in: Polyhedron Vol. 141; pp. 37 - 43
• Main Authors: Yao, Peng-Fei, Su, Chao-Hong, Wu, Tai-Xue, Li, You, Hao, Hong-Mei, Huang, Fu-Ping, Yu, Qing, Bian, He-Dong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.02.2018
• Subjects: Magnetism; Mercapto-tetrazole; Nickel clusters; Single-crystal structure; The “[sbnd]N[sbnd]N[sbnd]” bridge; Mercapto-tetrazole; Magnetism; Single-crystal structure; The “NN” bridge; Nickel clusters
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2017.11.016

Four polynuclear mercaptotetrazole-based nickel clusters, [Ni3(hmt)6(H2O)6]·4H2O (1), [(C2H5)4N]2[Ni9(μ3-CH3O)8(hmt)12] (2), [Ni5(μ3-OH)2(Hdmt)6(SCN)8] (3), and [Ni12(μ6-CO3)(μ3-CH3O)12(CH3CO2)3(et)6(H2O)12]·Br·2H2O (4), (here, Hhmt = 1-(2-hydroxyethyl)-5-mercapto-tetrazole, Hdmt = 1-[2-(N,N-dimethylamino)ethyl]-5-mercapto-tetrazole, Het = 5-(ethylthio)-1H-tetrazole), have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction and X-ray single-crystal diffraction. 1 shows a centrosymmetric linear trinuclear nickel cluster. 2 reveals of a dumbbell-like {Ni9} cluster with S3 symmetry containing two [Ni4(CH3O)4] cubanes linked with a Ni atom through six “NN” bridges. 3 reveals of a {Ni5} cluster with a bowtie-like skeleton supported by μ3-OH− ions. 4 exhibits a plane- symmetry {Ni12} cluster with an approximate trefoil shape based on three [Ni4(CH3O)4] cubanes bridged by a µ6-CO32−. The results show that the minor ligand modification accompanying the regulating of reaction conditions (anion, solvent, pH, temperatureand the different ratios) have a key role in the structural control of the self-assembly process. Magnetic properties of 1, 2 and 4 in the 2–300 K have also been discussed. The linear {Ni3} (1) core displays dominant anti-ferromagnetic interactions from the nature of the binding modes through “NN” bridges. The {Ni9} (2) and {Ni12} (4) clusters display dominant ferromagnetic interactions from the nature of the binding modes through µ3-CH3O− and “NN” bridges. [Display omitted] Four polynuclear mercaptotetrazole-based nickel clusters, [Ni3(hmt)6(H2O)6]·4H2O (1), [(C2H5)4N]2[Ni9(μ3-CH3O)8(hmt)12] (2), [Ni5(μ3-OH)2(Hdmt)6(SCN)8] (3), and [Ni12(μ6-CO3)(μ3-CH3O)12(CH3CO2)3(et)6(H2O)12]·Br·2H2O (4), (here, Hhmt = 1-(2-hydroxyethyl)-5-mercapto-tetrazole, Hdmt = 1-[2-(N,N-dimethylamino)ethyl]-5-mercapto-tetrazole, Het = 5-(ethylthio)-1H-tetrazole), have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction and X-ray single-crystal diffraction. 1 shows a centrosymmetric linear trinuclear nickel cluster. 2 reveals of a dumbbell-like {Ni9} cluster with S3 symmetry containing two [Ni4(CH3O)4] cubanes linked with a Ni atom through six “NN” bridges. 3 reveals of a {Ni5} cluster with a bowtie-like skeleton supported by μ3-OH− ions. 4 exhibits a plane- symmetry {Ni12} cluster with an approximate trefoil shape based on three [Ni4(CH3O)4] cubanes bridged by a µ6-CO32−. The results show that the minor ligand modification accompanying the regulating of reaction conditions (anion, solvent, pH, temperatureand the different ratios) have a key role in the structural control of the self-assembly process. Magnetic properties of 1, 2 and 4 in the 2–300 K have also been discussed. The linear {Ni3} (1) core displays dominant anti-ferromagnetic interactions from the nature of the binding modes through “NN” bridges. The {Ni9} (2) and {Ni12} (4) clusters display dominant ferromagnetic interactions from the natureof the binding modes through µ3-CH3O− and “NN” bridges.