Synthesis, spectral, magnetic and electrochemical properties of new dimeric copper(II) complexes

Four new ligands, bis-[3,5-disubstituted-2-hydroxybenzyl]-N-alkylamines (L- 1-L-4) with three potential donor sites, capable of forming dimeric copper( II) complexes have been prepared. The dimeric nature of the complexes has b een confirmed by FAB mass spectral studies. Molar conductance studies indic ate that the complexes are neutral. Electrochemical studies indicate that t he complexes undergo quasi reversible two step single electron transfers at negative potentials (E-pc(1)=-0.34 to -0.48 V, E-pc(2)=-0.59 to -0.72 V). Variable temperature magnetic studies indicate that the complexes are antif erromagnetically coupled (-2J=290 to 400 cm(-1)). ESR spectral studies in D MF indicate that the complexes are dimeric and undergo dissociation on addi tion of pyridine. (C) 1999 Elsevier Science Ltd. All rights reserved.