Palladium carbonyl acetate (PCA), a tetranuclear cluster with a planar nearly rectangular metal skeleton, and related clusters were synthesized. Clusters with planar square or tetrahedral Pd metal cores were prepared by reacting PCA with Na ~PMo(CO)~) OF 1 ,lO-phenanthroline (Phen) respectively. Palladium carbonyl hydrides of type (PdPhen(CO)H(OAc)ln, where n ~1 2 or 4, were synthesized and shorn to be catalysts for hydrogenation and olygomerization of alkenes and allqmes. Anionic octanuclear cluster Na2{Pd4(Cplo(C0)3) ,$ containing Pd-Mo bonds provides dehydration of alcohols evidently via a carbene mechanism. Products of decarbonylation of Pd phenantroline carbonyl clusters were shown to be active catalysts for oxidative acetoxylation and alcoxylation of unsaturated hydrocarbons.