Cyclopalladated complexes with 9-anthraldehyde aroylhydrazones: Synthesis, properties and structures

Abstract

Reactions of equimolar amounts of Li 2PdCl 4, 9-anthraldehyde 4-R-benzoylhydrazones (H 2L n; n = 1 and 2 for R = H and NMe 2, respectively) and CH 3COONa· 3H 2O in methanol produce the cyclopalladated complexes with the formula [Pd(HL n)Cl] (1 (R = H) and 2 (R = NMe 2)). Reactions of [Pd(HL n)Cl] (1 and 2) with 2 mol equivalents of PPh 3 in acetone provide the complexes of formula [Pd(L n)(PPh 3)] (3 (R = H) and 4 (R = NMe 2)). Complexes 1-4 have been characterized by elemental analysis and spectroscopic (IR, UV-vis, fluorescence and NMR) measurements. Molecular structures of 1-4 have been confirmed by X-ray crystallography. In [Pd(HL n)Cl] (1 and 2), the C,N,O-donor (HL n) - and the chloride form a CNOCl square-plane around the metal centre, while (L n) 2- and the PPh 3 assemble a CNOP square-plane around the metal centre in [Pd(L n)(PPh 3)] (3 and 4). © 2011 Elsevier B.V. All rights reserved.