Mechanism of Thermal Decomposition of Palladium β-Diketonates Vapour on Hot surface

Abstract

The processes of thermal decomposition of palladium(II) β-diketonate complexes were investigated by a high-temperature mass spectrometric method with the use of a high-temperature molecular beam source. It was established that decomposition of the palladium complexes in gas phase processes proceeds by a radical mechanism and depends on temperature. For an additional proof of the existence of the radical particles the spin trap method was applied with a mass spectrometric identification of adducts. The following order of thermal stability of the complexes in gas phase was established: Pd(hfac) 2 > Pd(tfac) 2 > Pd(dpm) 2 > Pd(acac) 2 . This order is reverse to the thermal stability in a solid state. The thermal decomposition of Pd(aa) 2 and Pd(hfa) 2 complexes in deuterium showed that the deuterium presence strongly accelerates the decomposition processes.