The platina-β-diketone Pt 2{(COMe) 2H} 2(μ-Cl) 2 ( A) was found to react with chelating N, N-ligands 2-(R ′NCR)C 5H 4N yielding acyl(hydrido)platinum(IV) complexes ( B) and with chelating S, S- and N, S-donors RS–CH 2–CH 2–SR and 2-(RSCH 2)C 5H 4N yielding acyl(chloro)platinum(II) complexes Pt(COMe)Cl(RSCH 2CH 2SR) and Pt(COMe)Cl{2-(RSCH 2)C 5H 4N} ( C), respectively. Results gave evidence that hard donors like N tend to react yielding stable platinum(IV) type B complexes whereas soft donors like S tend to react yielding platinum(II) type C complexes. The platina-β-diketone Pt 2{(COMe) 2H} 2(μ-Cl) 2 ( 1) was found to react with chelating N, N-ligands 2(R ′NCR)C 5H 4N (R/R ′=Ph/OH, H/Ph, Me/Ph) to form acyl(hydrido)platinum(IV) complexes Pt(COMe) 2Cl(H){2-(R ′NCR)C 5H 4N} (R/R ′=Ph/OH 2a; H/Ph 2b; Me/Ph ( 2c)). Reactions of complex 1 with chelating S, S- and N, S-donors (RS–CH 2–CH 2–SR, 2-(RSCH 2)C 5H 4N, R=Et, Ph, t-Bu) afforded acyl(chloro)platinum(II) complexes Pt(COMe)Cl(RSCH 2CH 2SR) (R=Et, 3a; Ph, 3b; t-Bu, 3c) and Pt(COMe)Cl{2-(RSCH 2)C 5H 4N} (R=Et, 4a; Ph, 4b; t-Bu, 4c), respectively. All complexes were fully characterized by microanalysis, IR and NMR ( 1H, 13C) spectroscopy. Furthermore, molecular structures of complexes 3b and 4b were determined by single-crystal X-ray diffraction analyses revealing close to square-planar configuration. In complex 4b the acetyl ligand is trans to pyridine N atom (configuration index SP-4-2). The reactions are discussed in terms of consecutive oxidative addition and reductive elimination reactions.