Synthesis, crystal structure and thermal behavior of dimethylgold(III) derivatives of salicylaldimine Schiff bases – Novel precursors for gold MOCVD applications

Abstract

Dimethylgold(III) complexes with salicylaldimine Schiff bases of general formula Me 2Au(Sal N–R) (R = methyl ( 1), iso-propyl ( 2), or cyclohexyl ( 3)) have been synthesized in a single step reaction from dimethylgold(III) iodide [Me 2AuI] 2 and N-substituted salicylaldimines. Single-crystal X-ray studies provide evidence of mononuclear four-coordinated complexes with square-planar coordination geometry. The temperature dependences of saturated vapour pressure of complexes have been studied by the Knudsen effusion method with mass spectrometric analysis of the composition of the gas phase. The thermodynamic parameters of the sublimation process Δ H o T and Δ S o T have been calculated. Thermal decomposition of the vapour of compounds has been studied by means of high temperature mass spectrometry in a vacuum, and by-products have been determined. All of these complexes show good volatility and thermal stability. For complex 2, which is more volatile and low-melting, pulse MOCVD experiments have been carried out at substrate temperatures lower than 200 °C. The deposited gold nanoparticles (5–15 nm) have been investigated by means of SEM and AFM.