A series of coordination polymers constructed from in situ amidation ligands: syntheses, structures and luminescent properties

From the hydrothermal in situ amidation reactions of aromatic polycarboxylates and hydrazine hydrate (N2H4 center dot H2O), four complexes, dinuclear [Cu(mu(2)-H(3)bbch)(H2O)](2)center dot 2H(2)O (1), 3-D grid-like [Fe-3(mu(5)-Hbbch)(2)(mu(2)-H2O)(2)(H2O)(2)]center dot 2H(2)O (2), 2-D layer [Zn(mu(2)-H(2)bbh)(mu(2)-N2H4)(1/2)(H2O)]center dot 2H(2)O (3) and 3-D supramolecular structure [Cd(H(2)bch)(2)(2,2'-bpy)(H2O)(2)][Cd(mu(2)-H(2)bch)(2,2'-bpy)(H2O)(2)](H(2)bch) (4) have been prepared. The two different in situ amidated ligands in 1, 2 and 3, benzene-4,5-bicarboxylate-1,2-hydrazide (H(4)bbch) and benzene-1,2,4,5-bihydrazide (H(4)bbh), were formed through adjusting the ratios of pyromellitic acid (PMA) and N2H4 center dot H2O, of which H(4)bbch was generated through hydrothermal in situ amidation reactions for the first time. Benzene-4-carboxylate-1,2-hydrazide (H(3)bch), displaying three new coordination modes in 4, was also an in situ amidation product of benzene-1,2,4-tricarboxylic acid (H(3)btca) and N2H4 center dot H2O. 1-4 were characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Their structures were determined by single-crystal X-ray diffraction. The fluorescence properties of compounds 1, 3 and 4 were also investigated.