Syntheses, Characterization, and Magneto–Structural Analyses in μ 1,3 ‐Acetato‐Bridged Tetracopper(II) and μ 1,3 ‐ and μ 1,1,3 ‐Acetato‐Bridged Pentanickel(II) Clusters

Autor: Lorenzo Sorace, Averi Guha, Debasis Das, Andrea Caneschi, Ria Sanyal, Hulya Kara, Ennio Zangrando, Sudhanshu Das
Rok vydání: 2014
Předmět:
Zdroj: European Journal of Inorganic Chemistry. 2014:2753-2765
ISSN: 1099-0682
1434-1948
DOI: 10.1002/ejic.201301581
Popis: Two pentanuclear NiII complexes, [Ni5(L1)2(CH3COO)6(OH)2(MeOH)2] (1) and [Ni5(L2)2(CH3COO)6(OH)2(H2O)2] (2), and one tetranuclear CuII complex, [Cu4(L3)2(CH3COO)4(O)] (3), have been synthesized from phenol-based “end-off” compartmental ligands HL1 to HL3 {HL1 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-tert-butylphenol; HL2 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-chlorophenol and HL3 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-methylphenol, respectively}. The complexes have been structurally characterized and their magnetic properties have been investigated within the temperature range 2.2–300 K. Complexes 1 and 2 comprise two dinuclear [Ni2L2] units linked to a central Ni ion by bridging μ3-hydroxo groups. The cluster is stabilized by syn-syn-μ1,3-bridging and μ1,1,3-bridging acetate anions. The structural analysis of 3 revealed two crystallographically independent complexes that consisted of a tetrahedron of CuII ions connected to a central μ4-oxo species and further bridged by four acetate groups along four of the six edges of the Cu4 core. The other two edges are occupied by μ-phenoxo bridges from the deprotonated L3 ligand. Magnetic investigations revealed both ferromagnetic and antiferromagnetic interactions in 1 and 2 with single-ion zero-field splitting of magnitude comparable to exchange interactions, and strong antiferromagnetic interactions in 3.
Databáze: OpenAIRE
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