title: Tautomeric structures, electronic spectra, acid-base properties of some 7-aryl-2,5-diamino-3(4-hydroxyphenyazo)pyrazolo[1,5-a]pyrimidine-6-carbonitriles, and effect of their copper(II) complex solutions on some bacteria and fungi.
abstract: Infrared and electronic spectra were used to investigate the tautomerism of some azo compounds, in both the solid and solution states. It was found that the compounds exist in azo<==>hydrazone tautomeric equilibrium in solid and in solutions. The different bands displayed in the electronic spectra of the compounds in various organic solvents are assigned to the suitable electronic transitions. The solvatochromic behavior of the compounds was investigated by studying their visible spectra in pure and mixed organic solvents. DeltaG and formation constant, Kf, values of the molecular complexes formed in solution have been determined. Effect of concentration of the compounds in DMF and EtOH solutions has been investigated. The basicity and acidity constants of the different compounds were determined from the spectra of these compounds in aqueous-ethanolic solutions of varying pH values. Some complexes of copper(II) with these compounds in solution were tested as for their antibacterial and antifungal activity.
authors.affiliation: Department of Chemistry, Faculty of Science, South Valley University, Qena, Egypt. nasmrageh@yahoo.com
authors.forename: Nasr M
authors.initials: NM
authors.lastname: Rageh
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry* / Q000494:pharmacology*; D001391:Azo Compounds / Q000737:chemistry* / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D012997:Solvents; D013053:Spectrophotometry; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D001391:Azo Compounds; D012997:Solvents; D003300:Copper