Studies of thermal decomposition of palladium(II) complexes with olefin ligands

PdCl2(VTMS)2 (1), PdCl2(PTMSA)2 (2), PdCl2(DMB)2 (3) and PdCl2(DADMS)2 (4), where VTMS–trimethyl(vinyl)silane, DADMS—diallyldimethylsilane, PTMSA—1-phenyl-2-(trimethylsilyl)acetylene and DMB–2,3-dimethyl-2-butene were prepared and thermal characteristic studied by TG/DTG/DTA techniques. TG/IR method was used for the gas phase studies of ligands and complexes in the range 303–573 K. MS–EI analysis data were applied for elucidation of the metallated species in the gas phase. Thermal analysis results indicate detachment of organic ligand in the first stage of decomposition, whereas the chlorine molecule in the second stage. Metallic palladium was the final product of decomposition, what was confirmed by XRD analysis of the residues heated up to 1273 K. The metallic palladium was formed in the temperature range 478–720 K, what make the complexes (1–4) a promising Chemical Vapour Deposition (CVD) precursors. TG/IR spectra of all palladium(II) complexes revealed bands characteristic for appropriate ligands vibrations, what confirm the proposed mechanism of thermal decomposition. The MS results indicate the palladium fragments detachment in the temperature range 321–548 K. The organic and chlorine species were also observed.