title: Supramolecular structure, mixed ligands and substituents effect on the spectral studies of oxovanadium(IV) complexes of bioinorganic and medicinal relevance.
abstract: An interesting series of heterocyclic mixed ligand of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) sulfate with rhodanine azo (HL(n)) in the presence of β-diketon (LH). The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)HNMR and ESR) with thermal studies were used to characterize the isolated complexes. The IR showed that the ligands (HL(n) and LH) act as a monobasic bidentate through the (NN), oxygen keto moiety and oxygen atom of the two enolate groups thereby forming a six-membered. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in d(xy) orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry around oxovanadium(IV) in all complexes is a hex-coordinated trans octahedral, with one bidentate ligand (L(n)), and one bidentate ligand (L). Electronic and magnetic data proposed the octahedral structure for all complexes under investigation. ESR spectra of VO(2+) reveal data that confirmed the proposed structure. The value of covalency factor (β(1)(∗))(2) and orbital reduction factor K accounts for the covalent nature of the complexes. All electronic transitions were assigned. The Hammett's constant is also discussed.
authors.affiliation: Chemistry Department, Faculty of Science (Demiatta), Mansoura University, Egypt. elsonbatisch@yahoo.com
authors.forename: A Z
authors.initials: AZ
authors.lastname: El-Sonbati
authors.forename: A A M
authors.initials: AA
authors.lastname: Belal
authors.forename: M S
authors.initials: MS
authors.lastname: El-Gharib
authors.forename: Sh M
authors.initials: ShM
authors.lastname: Morgan
mesh_terms: D015393:Chemistry, Bioinorganic; D002626:Chemistry, Pharmaceutical; D056831:Coordination Complexes / Q000737:chemistry*; D004553:Electric Conductivity; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D012236:Rhodanine / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013818:Thermogravimetry; D014638:Vanadates / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D008024:Ligands; C075743:oxovanadium IV; D014638:Vanadates; D012236:Rhodanine