Structure, Spectral and Magnetic Properties of 3‐(<i>p</i>‐Pyridyl)‐1,5‐diphenylverdazyl (<i>p</i>‐PyV) and the Binuclear Copper(II) Radical Complex [Cu₂(OCOCH₃)₄(<i>p</i>‐PyV)₂]

Abstract

Abstract 3‐( p ‐Pyridyl)‐1,5‐diphenylverdazyl ( p ‐PyV) and its binuclear copper(II) complex [Cu 2 (OCOCH 3 ) 4 ( p ‐PyV) 2 ] have been synthesized and structurally characterized. The magnetic behavior of a single crystal of p ‐PyV and [Cu 2 (OCOCH 3 ) 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 antiferromagnetic interactions in the radical crystal lattice. The exchange interactions between the copper(II) ion and p ‐PyV in Cu 2 (OCOCH 3 ) 4 ( p ‐PyV) 2 were found to be negligibly small compared to the strong intramolecular copper–copper antiferromagnetic interaction. Intermolecular antiferromagnetic coupling between p ‐PyV molecules was detected in the crystal lattice of complex.(© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2009)