Binuclear Orthometalated N,N-Dimethylbenzylamine Complexes of Palladium(II): Synthesis, Structures and Thermal Behavior

Abstract

Abstract Organochalcogenolate-bridged cyclometalated palladium(II) complexes of the formulae, [Pd2(μ-Epy)2(Me2NCH2C6H4-C,N)2] (2) (E = S (2a), Se (2b)), [Pd2(μ-SAr)(μ-Cl)(Me2NCH2C6H4-C,N)2] (3) (Ar = Ph (3a), Mes (Mes = 2,4,6-Me3C6H2) (3b)) and [Pd2(μ-SeAr)2(Me2NCH2C6H4-C,N)2] (4) (Ar = Ph (4a), Mes (4b)), have been synthesized by the reactions of [Pd2(μ-Cl)2(Me2NCH2C6H4-C,N)2] with lead or sodium salts of the chalcogenolate ligand. These complexes have been characterized by elemental analysis, mass spectral data, and NMR (1H and 77Se{1H}) spectroscopy. The molecular structure of 2, determined by single crystal X-ray diffraction analysis, revealed a Epy-bridged head-to-tail arrangement in which the eight-membered “(PdECN)2” ring adopts a distorted twist boat conformation. The Pd····Pd separation in 2a is within the van-der-Waals interaction but in 2b it is too large to support the presence of any metal–metal interaction. The thermal behavior of these complexes has been studied by thermogravimetric analysis.