Journal of Thermal Analysis and Calorimetry, Vol. 64 (2001) 1171–1182 VOLATILE β-DIKETONATO COMPLEXES OF RUTHENIUM, PALLADIUM AND PLATINUM Preparation and thermal characterization M. Lashdaf 1 , T. Hatanpää 2 and M. Tiitta 3 1 Volatec Oy, Linnankoskenkatu 34, FIN-06100 Porvoo, Finland 2 Department of Chemistry, University of Helsinki, Laboratory of Inorganic Chemistry, P. O. Box 6, FIN-00014 Helsinki, Finland 3 Fortum Oil and Gas, Oil Research, P.O. Box 310, 06101 Porvoo, Finland Abstract Ruthenium, palladium and platinum complexes of 2,2,6,6-tetramethyl-3,5-heptanedione (thd) and ruthenium tris acetylacetonate (acac) were synthetized and studied with TG, DTA, DSC and MS methods. Thermal properties of ruthenocene were also studied. The platinum thd complex has the highest volatility despite the second highest molecular mass of the complex. All the complexes sub- limed under reduced pressure. Ru(acac) 3 decomposed during sublimation under atmospheric pres- sure of nitrogen whereas the other compounds studied sublimed also under these conditions. Pd(thd) 2 reduced under atmospheric pressure of H 2 /N 2 (5% H 2 ) whereas the ruthenium complexes were not reduced. The field desorption mass spectra of complexes showed only the molecular peaks and no fragmentation occurred. Keywords: atomic layer epitaxy, catalyst precursor, chemical vapor deposition, decomposition, diketonate, platinum, palladium, reduction, ruthenium, ruthenocene, sublimation Introduction Heterogeneous catalysts typically consist of active metals supported on porous high surface area material. The Ru, Pd and Pt metals on supports play an important role as catalysts for the various hydrogenation reactions in the industrial chemistry and in the production of fine chemicals [1]. Typically, Ru, Pd and Pt containing catalysts are prepared by precipitation or by deposition methods such as impregnation [2] or ion exchange [3]. Chemical vapor deposition (CVD) and atomic layer epitaxy (ALE) are thin film deposition methods that have also been used for the preparation of different hydroge- nation catalysts [4, 5]. For a comprehensive review of the adsorption-controlled prep- aration of heterogeneous catalysts, see the article by Haukka et al. [6]. Essential for both the CVD and ALE depositions are volatile precursors that do not decompose during vaporisation. In addition, precursors should be non-pyrophoric, easy to handle and store, pure and non-toxic. Metal β-diketonates meet most of these criteria [7]. In 1418–2874/2001/ $ 5.00 © 2001 Akadémiai Kiadó, Budapest Akadémiai Kiadó, Budapest Kluwer Academic Publishers, Dordrecht