μ2-Oxalato-bridged tricopper(II) complex derived from 1,4,8,12-tetraazacyclopentadecane: Synthesis, structure and magnetic characterization
摘要:
A novel tricopper bridged oxalato complex with the structural formula [Cu(tacp)(H2O)](2)[Cu(mu(2)-C2O4)(2)(ClO4)(2)] (1) where tacp = 1,4,8,12-tetraazacyclopentadecane was synthesized. The complex was characterized by X-ray crystallography and by spectroscopic techniques (IR and visible). The magnetic properties were also measured at variable temperatures (300-2 K). In this compound each oxalate is acting as a bridging ligand between two Cu2+ ions, where two types of coordination modes are found for the oxalate: monodentate and bidentate fashions. The magnetic coupling between the Cu-Cu centers is very weak antiferromagnetic (the singlet-triplet energy coupling J = -0.9 cm(-1)) and is in full agreement with the structural results. (C) 2008 Elsevier B.V. All rights reserved.