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, [Cu3(2,5-pydc)2(Me5dien)2(BF4)2(H2O)2] · H2O 1, has been constructed from 2,5-pyridine-dicarboxylato bridges (2,5-pydc2−) and N ,N ,N ′,N ″,N ″-pentamethyl-diethylenetriamine (Me5dien) acting as a blocking ligand. The copper ions, within the centrosymmetric trinuclear cations, are connected by two 2,5-pydc2− bridges, with an intramolecular Cu···Cu separation of 8.432 Å. The central copper ion exhibits an elongated octahedral geometry, with semicoordinated View the MathML source(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 = −JSCu1SCu2 − JSCu2SCu1a).