Synthesis, magnetic behaviour and structural characterization of the alternating hexanuclear copper( II ) compound [Cu 6 (tmen) 6 (µ-N 3 ) 2 (µ-C 2 O 4 ) 3 (H 2 O) 2 ][ClO 4 ] 4 ·2H 2 O (tmen = Me 2 NCH 2 CH 2 NMe 2 )

The compound [Cu6(tmen)6(µ-N3)2(µ-C2O4)3(H2O)2][ClO4]4·2H2O 1 where tmen is N,N,N′,N′-tetramethylethane-1,2-diamine, was synthesized and characterized. Its crystal structure was determined by single-crystal X-ray analysis. The magnetic behaviour was recorded between 300 and 4 K, showing strong antiferromagnetic coupling. The magnetic susceptibility data were fitted by the expression for a dinuclear copper(II) compound giving the parameters J=–289(2)cm–1, g= 2.03(1). Polycrystalline powder ESR spectra were recorded at variable temperature. The broad room-temperature signal having g= 2.12 vanished at approximately 55 K.