New pyridine-monoacylhydrazidate-coordinated transition-metal complexes

Abstract: By applying the hydrothermal in situ acylation reactions between alkyl-substituted pyridine-2,3-dicarboxylic acids and hydrazine hydrate, six pyridine-monoacylhydrazidate-coordinated transition-metal complexes [Mn(MPDH)2] 1, [M(MPDH)2(H2O)2]·2H2O (M2+ =Co2+ 2, Zn2+ 3), [Mn(EPDH)2(H2O)2] 4 and [M(EPDH)2(H2O)2] (M2+ =Zn2+ 5, Co2+ 6) (MPDH=6-methylpyridine-2,3-dicarboxylhydrazidate; EPDH=5-ethylpyridine-2,3-dicarboxylhydrazidate) were obtained. Although only compound 1 is a 1-D chained coordination polymer and the others are the mononuclear molecular entities, they all further self-assemble into the interesting supramolecular networks via hydrogen-bonded interactions between pyridine-monoacylhydrazidate ligands. Two Zn2+ compounds 3 and 5 possess the fluorescence properties with maximum emissions at 517nm for 3 and 530nm for 5 upon excitation, respectively. The magnetic analysis for compound 1 indicates there exists the antiferromagnetic interactions between the Mn(II) ions. [Copyright &y& Elsevier]