Cobalt(II) complexes of biologically active glutathione: spectroscopic and molecular modeling studies

Light-driven hydrogen production with CdSe quantum dots and a cobalt glutathione catalyst

A photocatalytic hydrogen (H₂) production system is reported using glutathione (GSH)-capped CdSe QDs with a cobalt precatalyst, yielding 130 000 mol H₂ per mol cobalt over 48 hours. Analysis of the reaction mixtures after catalysis indicates that the active catalyst is a labile complex of cobalt and GSH formed in situ.

Nitrogen-doped graphene quantum dots coupled with photosensitizers for one-/two-photon activated photodynamic therapy based on a FRET mechanism

Photosensitizers can be excited by nitrogen-doped graphene quantum dots under one-/two-photon excitation through an intramolecular FRET mechanism and induced phototoxicity.

Spectroscopic characterization and biological activity of Zn(II), Cd(II), Sn(II) and Pb(II) complexes with Schiff base derived from pyrrole-2-carboxaldehyde and 2-amino phenol

A new Schiff base 2-aminophenol-pyrrole-2-carboxaldehyde and its Zn(II), Cd(II), Sn(II) and Pb(II) complexes have been synthesized and characterized by various physicochemical studies. Spectral studies (IR and (1)H NMR) indicate deprotonation and coordination of phenolic oxygen along with binding of pyrrole nitrogen, azomethine nitrogen and anion with metal ions. The presence of lattice water molecule(s) has also been confirmed by TG/DTA studies. Mass spectrum explains the successive degradation of the molecular species in solution and justifies ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. The bio-efficacy of the ligand and their complexes has been examined against the growth of bacteria in vitro to evaluate their antimicrobial potential. Molecular structures of the complexes have been optimized by MM2 calculations and suggest a tetrahedral geometry around metal ions.

Cobalt(II) complexes of new biomimetic polydentate amide: spectroscopic, kinetics of thermal decomposition and XRPD studies

Complexes of Co(II) with new ligands N',N''-bis(3-carboxy-1-oxoprop-2-enyl) 2-amino-N-arylbenzamidine (C(21)H(17)N(3)O(6)), N',N''-bis(3-carboxy-1-oxopropanyl) 2-amino-N-arylbenzamidine (C(21)H(21)N(3)O(6)) and N',N''-bis(3-carboxy-1-oxophenelenyl) 2-amino-N-arylbenzamidine (C(29)H(21)N(3)O(6)) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, TOF-mass spectra, magnetic susceptibility measurements, thermal studies and X-ray powder diffraction studies. Vibrational spectra indicate coordination of amide and carboxylate oxygen of the ligands along with two water molecules giving a MO(6) weak field octahedral chromophore. Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for Co(II) complexes. The elemental analyses and mass spectral data have justified the ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first-order kinetics. Powder diffraction determines the cell parameters of the complexes.

Synthesis and spectrothermal studies on group 12 metals coordination with novel carboxyamide ligands

Complexes of group 12 metals with new ligands N',N''-bis(3-carboxy-1-oxopropanyl) 2-amino-N-arylbenzamidine (H2L) and N',N''-bis(3-carboxy-1-oxophenelenyl) 2-amino-N-arylbenzamidine (H(2)L) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, (1)H NMR spectra, TOF-mass spectra, thermal studies and molecular modeling studies. The infrared and (1)H NMR spectral data are in agreement with coordination of amide and carboxylate oxygen of the ligands giving a MO(4) tetrahedral chromophore. The elemental analyses and mass spectral data have justified the ML complexes. The thermal behaviour of complexes shows that water molecule is removed in first step--followed by decomposition of the rest of the molecule in the next steps. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. Molecular structures of the complexes have been optimized by MM2 calculations and supported tetrahedral geometry around metal(II) ions.

Synthesis, characterization and biological activity of complexes of 2-hydroxy-3,5-dimethylacetophenoneoxime (HDMAOX) with copper(II), cobalt(II), nickel(II) and palladium(II)

A new series of complexes of 2-hydroxy-3,5-dimethyl acetophenone oxime (HDMAOX) with Cu(II), Co(II), Ni(II) and Pd(II) have been prepared and characterized by different physical techniques. Infrared spectra of the complexes indicate deprotonation and coordination of the phenolic OH. It also confirms that nitrogen atom of the oximino group contributes to the complexation. Electronic spectra and magnetic susceptibility measurements reveal square planar geometry for Cu(II), Ni(II) and Pd(II) complexes and tetrahedral geometry for Co(II) complex. The elemental analyses and mass spectral data have justified the ML(2) composition of complexes. Kinetic and thermodynamic parameters were computed from the thermal decomposition data using Coats and Redfern method. The geometry of the metal complexes has been optimized with the help of molecular modeling. The free ligand (HDMAOX) and its metal complexes have been tested in vitro against Alternarie alternate, Aspergillus flavus, Aspergillus nidulans and Aspergillus niger fungi and Streptococcus, Staph, Staphylococcus and Escherchia coli bacteria in order to assess their antimicrobial potential. The results indicate that the ligand and its metal complexes possess antimicrobial properties.