(Schiff‐base)Cu^II Complexes with Phenolate‐Oxygen/Chloro or ‐Oxygen/Azido Mixed Bridges − Syntheses, Crystal Structures and Magnetic Properties

Abstract

Abstract Four new Cu II complexes of formulae [Cu 3 (SE) 2 (H 2 O) 2 Cl 3 ]Cl·6H 2 O ( 1 ), Cu 3 (SE) 2 (N 3 ) 4 (DMF) 2 ( 2 ) , Cu(SE)N 3 ·DMF ( 3 ) and Cu(SE)N 3 ·Cu(SE)N 3 ( 4 ) with tridentate Schiff‐base ligands SE − , derived from condensation of N , N ‐dimethylethylenediamine with salicylaldehyde, have been synthesised and characterised by IR spectroscopy, X‐ray structural analyses and variable‐temperature magnetic susceptibility measurements. Complex 1 has an alternating phenoxy‐ and chloro‐bridged 1D chain structure. Complex 2 possesses trinuclear units in which the Cu II ions are bridged by single end‐on (µ‐1,1) azido ligands. Uniformly spaced 1D chains with end‐to‐end (µ‐1,3) azido bridges are found in 3 and 4 . As expected, complexes 1 and 2 exhibit antiferromagnetic and ferromagnetic exchange, respectively. Compounds 3 and 4 show unusual ferromagnetic coupling though the 1,3‐azido pathways. Theoretical simulations have been carried out in order to evaluate the magnitude of the magnetic exchange and the magneto‐structural correlation has been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)