Novel linear acetylpentanedionato complexes for metal–organic framework construction

Abstract

The novel metal complexes bis(3-acetyl-2,4-pentanedionato-O2,O3)palladium(II), Pd[C₇O₃H₉]₂, and bis(3-acetyl-2,4-pentanedionato-O2,O3)magnesium(II), Mg[C₇O₃H₉]_2, have been synthesized. They are comprehensively characterized by a number of complementary methods. Spectroscopic data of the molecules in solution have been obtained by means of ¹H- and ¹³C NMR. X-Ray powder diffractograms, IR- and micro-Raman spectra have been obtained from polycrystalline material and are discussed in detail. The crystal structures have been determined from laboratory X-ray powder diffraction data and subsequently refined with the Rietveld technique. In both complexes, the central metal cation is coordinated by two chelating ligands, forming a square-planar coordination. The crystal structure of the palladium(II) complex is comprised of isolated molecules the stability and catalytic capabilities of which make the compound a promising candidate as a metal–organic frameworks (MOF) interlinker. In contrast, the magnesium(II) complex undergoes supplementary intermolecular ligation to complete an octahedral coordination of the Mg(II), resulting in an extended layer structure. Line-shifts and -splittings in the Raman spectra are identified, from which the structural features of further complexes could be identified.