Novel mixed-ligand palladium complexes [Pd2(acac)3NO3] and [Pd(acac)NO3]n involving O,O- and γ-C-bonded acetylacetonate linkers

The reaction of the palladium nitrate trans-[Pd(NO3)2(H2O)2] with acetylacetone affords mononuclear [Pd(acac)2] (acac = acetylacetonate), mixed-ligand binuclear [Pd2(acac)3NO3] (1) and polynuclear [Pd(acac)NO3]n (2) complexes depending on the Pd:acetylacetone ratio in the reaction mixture. The binuclear 1 and insoluble polynuclear 2 were isolated and studied by single-crystal X-ray diffraction (1) and solid-state 13C MAS NMR (1 and 2). It was found that in both compounds the Pd ions are linked together through bridging acetylacetonate ligands where one metal atom is connected to the usual O,O-donor sites, whereas the other metal atom forms a bond with the γ-carbon center. Based on a topological quantum-chemical method, the Pd–γ-C bond was classified as a strained dative bond.

Graphical abstractThe binuclear [Pd2(acac)3NO3] and insoluble polynuclear [Pd(acac)NO3]n were isolated and studied by single-crystal X-ray diffraction and solid-state 13C MAS NMR.Figure optionsDownload full-size imageDownload as PowerPoint slide