Parashuram Mishra

Spectroscopic characterization of complexes of tetracycline with cobalt(II), nickel(II), cadmium(II) and inorganic Sn(II)

Complexes of Co(II), Ni(II), Cd(II) and inorganic Sn(II) with tetracycline (TC) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, 1H NMR spectra, magnetic susceptibility measurement, thermal studies and X-ray powder diffraction studies. TC forms a 1:1 complex with the metal ions through the oxygen of the hydroxyl group at the A ring and the carbonyl oxygen atom of the amide group in coordination. The results of spectral techniques and magnetic susceptibility measurement correlate well. Kinetic and thermodynamic parameters were computed from the thermal data using the Coats and Redfern method, which confirm first order kinetics. X-ray powder diffraction data determined the cell parameters of the complexes. The molecular structures of the complexes have been optimized by MM2 calculations and supported square planar/tetrahedral geometry around Metal (II) ions.

Syntheses and characterization of new polydentate amide ligands with inorganic tin (II) and lead (II) ions

Complexes of inorganic Sn(II) and Pb(II) with new ligands N′,N″-bis(3-carboxy-1-oxopropanyl) 2-amino-N-arylbenzamidine (C21H21N3O6) and N′,N″-bis(3-carboxy-1-oxophenelenyl) 2-amino-N-arylbenzamidine (C29H21N3O6) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, 1H NMR spectra, TOF-mass spectra, thermal studies and X-ray powder diffraction studies. The infrared and 1H NMR spectral data are in agreement with coordination of amide and carboxylate oxygen of the ligands giving a MO4 tetrahedral chromophore. The elemental analyses and mass spectral data are consistent with the formation of ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. X-ray powder diffraction determines the cell parameters of the complexes. Molecular structures of the complexes have been optimized by MM2 calculations and suggest a tetrahedral geometry around metal (II) ions.

Synthesis, characterization and XRPD studies of the bioactive complex of 2-hydroxy-3,5-dimethyl acetophenoneoxime (HDMAOX) with oxovanadium(IV)

The complex of 2-hydroxy-3,5-dimethyl acetophenoneoxime (HDMAOX, HL) with VO(IV) has been synthesized and characterized by different physical techniques. Infrared spectra indicate deprotonation and coordination of the phenolic OH, and nitrogen of the oximino group. Electronic spectra and magnetic susceptibility measurements support square-pyramidal geometry around the metal ion. The elemental analyses and mass spectral data indicate ML2 composition. Thermodynamic activation parameters were computed from the thermal data using the Coats and Redfern method. The crystal data for C20H24N2O5V are: tetragonal, space group P4/m, a = 11.76975 Å, b = 11.76975 Å, c = 18.89209 Å, V = 2617.06 A3, Z = 4. The free ligand (HDMAOX) and its oxovanadium complex have been tested in vitro against Alternaria alternate, Aspergillus flavues, Aspergillus nidulans and Aspergillus niger fungi and Streptococcus, Staph, Staphylococuss and Escherchia coli bacteria in order to assess their antimicrobial potential. The results indicate that the ligand and its metal complex have antimicrobial properties.