Synthesis and structural characterization of three hydrogen-bonding connected supramolecular complexes of nickel, zinc and copper with 1,3-diphenyl-4-(salicylidene hydrazide)-acetyl-pyrazolone-5 and 2,2′-bipyridine

A new set of supramolecular complexes, [Ni(DPAP-SHZ)(2,2′-bipy)CH₃OH] (1), [Zn(DPAP-SHZ)(2,2′-bipy)CH₃OH] (2) and [Cu(DPAP-SHZ)(2,2′-bipy)] · 2CH₂Cl₂ (3) (DPAP-SHZ = 1,3-diphenyl-4-(salicylidene hydrazide)-acetyl-pyrazolone-5, 2,2′-bipy = 2,2′-bipyridine) have been synthesized and characterized by elemental analysis, TG-DTA, IR spectroscopy and X-ray crystallography. The X-ray diffraction analyses of the complexes show that the Ni(II) ion and Zn(II) ion centers are six-coordinated while the Cu(II) ion center is five-coordinated. The three supramolecular complexes contain the same ligands, namely DPAP-SHZ and 2,2′-bipy. However, their hydrogen bonds are significantly different, and this variation apparently is responsible for the dissimilar structures of the three supramolecular complexes.