Synthesis, spectral, thermal, and chelation potentials of polymeric hydrazone based on 2,4‐dihydroxy benzophenone

Abstract

A chelating polymer, poly(2,4-dihydroxy benzophenone hydrazone-formaldehyde) [poly(DHBPH-F)], was synthesized by the polycondensation of 2,4-dihydroxy benzophenone hydrazone with formaldehyde in the presence of oxalic acid as a catalyst. Poly(DHBPH-F) was characterized by Fourier transform infrared and 1 H-NMR spectral data. The molecular weight of the polymer was determined by gel permeation chromatography. Polychelates were obtained when the dimethylformamide solution of the polymer containing a few drops of ammonia was treated with an aqueous solution of metal ions. Elemental analysis of the polychelates indicated that the metal-ligand ratio was 1 : 2. The IR spectra of the polymer-metal complexes suggested that the metals were coordinated through the oxygen of the phenolicAOH group and the nitrogen of the azomethine group. The electron paramagnetic resonance and magnetic moment data indicated a square planar configuration for Cu(II) chelate and an octahedral structure for Ni(II) chelate. The thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction data indicated that the incorporation of the metal ions significantly enhanced the degree of crystallinity. The polymerization initiation, electrical conductivity, and catalytic activity of the polychelates are discussed. Heavy-metal ions [viz., Cu(II) and Ni(II)] were removed with this formaldehyde resin, and the metal-ion uptake efficiency at different pH's, the nature and concentration of the electrolyte, and the reusability of the resin were also studied.

Chelating and biological properties of an azo polymer resin: synthesis, characterization and its application

“…The polymeric metal complexes were placed in a desorption medium containing 7 mol L À1 HCl, and the amount of metal ions released was determined. The desorption ratios for the metal ions used in this study were calculated using the equation: 28,29 Desorption ratio ¼ Amount of metal ions released Amount of metal ions adsorbed on resin  100…”

Synthesis, Characterization and Biological Activities of Cu(II), Co(II), Mn(II), Fe(II), and UO2(VI) Complexes with a New Schiff Base Hydrazone: O-Hydroxyacetophenone-7-chloro-4-quinoline Hydrazone

“…The development of the field of bioinorganic chemistry has increased the interest in Schiff base complexes, since it has been recognized that many of these complexes may serve as models for biologically important species [ 1 , 2 , 3 , 4 , 5 ]. The remarkable biological activity of the acid hydrazide (R–CO–NH–NH 2 ) class of Schiff base, their corresponding aroylhydrazones (R–CO–NH–N=CH–R) and the dependence of their mode of chelation with transition metal ions present in the living systems have been of significant interest [ 6 , 7 , 8 , 9 , 10 , 11 ]. The coordination compounds of aroyl-hydrazones have been reported to act as enzyme inhibitors and are useful due to their pharmacological applications [ 6 , 7 , 8 , 9 , 10 , 11 ].…”

“…The remarkable biological activity of the acid hydrazide (R–CO–NH–NH 2 ) class of Schiff base, their corresponding aroylhydrazones (R–CO–NH–N=CH–R) and the dependence of their mode of chelation with transition metal ions present in the living systems have been of significant interest [ 6 , 7 , 8 , 9 , 10 , 11 ]. The coordination compounds of aroyl-hydrazones have been reported to act as enzyme inhibitors and are useful due to their pharmacological applications [ 6 , 7 , 8 , 9 , 10 , 11 ]. Isonicotinic acid hydrazide (INH) is a drug of proven therapeutic importance and is used for bacterial ailments, e.g., tuberculosis.…”

Transition Metal Complexes of (E)-N’-(4-cyanobenzylidene)nicotinohydrazide): Synthesis, Structural and Anti-Mycobacterial Activity Study

“…According to reports, the stereochemistry of the hydrazones is determined by the steric effects of the various substituents in the hydrazones moieties (Pavan et al, 2010;Al-Shaalan, 2011). The coordinating sites can be increased by substituting R groups with substituents with more coordinating sites and through this, several hydrazones with better coordination ability have been synthesized (Sankar et al, 2010).…”