Structure, spectral and magnetic properties of 3-(p-Pyridyl)-1,5- diphenylverdazyl (p-PyV) and the binuclear copper(II) radical complex [Cu 2(OCOCH3)4(p-PyV)2]

Abstract

3-(p-Pyridyl)-1,5-diphenylverdazyl (p-PyV) and its binuclear copper(II) complex [Cu2(OCOCH3)4(p-PyV)2] have been synthesized and structurally characterized. The magnetic behavior of a single crystal of p-PyV and [Cu2(OCOCH3) 4(p-PyV)2] have been studied by magnetic susceptibility measurements in the temperature range 2-300 K and by ESR spectroscopy. Data fitting for p-PyV using the singlet-triplet equilibrium model revealed the existence of antiferromag-netic interactions in the radical crystal lattice. The exchange interactions between the copper(II) ion and p-PyV in Cu 2-(OCOCH3)4(p-PyV)2 were found to be negligibly small compared to the strong intramolecular copper-copper antiferro-magnetic interaction. Intermolecular antiferromagnetic coupling between p-PyV molecules was detected in the crystal lattice of complex. © Wiley-VCH Verlag GmbH & Co. KGaA.