A trinuclear copper(II) complex with 2,5-pyridine-dicarboxylato bridges - [Cu3(2,5-pydc)2(Me5dien)2(H2O)2(BF4)2] • H2O: Synthesis, crystal structure and magnetic properties

A trinuclear copper(II) complex, [Cu-3(2,5-pydc)(2)(Me(5)dien)(2)(BF4)(2)(H2O)(2)] center dot H2O 1, has been constructed from 2,5-pyridine-dicarboxylato bridges (2,5-pydc(2) ) and N,N,N',N '',N ''-pentamethyl-diethylenetriamine (Me(5)dien) acting as a blocking ligand. The copper ions, within the centrosymmetric trinuclear cations, are connected by two 2,5-pydc(2) bridges, with an intramolecular Cu center dot center dot center dot Cu separation of 8.432 angstrom. The central copper ion exhibits an elongated octahedral geometry, with semicoordinated (BF4-) ions, while the terminal ones are pentacoordinated (distorted square-pyramidal geometry). The cryomagnetic investigation of 1 reveals an antiferromagnetic coupling of the copper(II) ions (J = -5.9 cm (1), H = -JS(Cu1)S(Cu2) - JS(Cu2)S(Cu1a)). (C) 2008 Elsevier B.V. All rights reserved.