title: Spectroscopic, potentiometric and theoretical studies of novel imino-phenolate chelators for Fe(III).
abstract: The present study was targeted to explore the binding properties of two strong chelators for Fe(III) based on tripodal-iminophenolate moiety. Complexation behavior of the tripodal systems cis-cis cyclohexane-1,3,5-tricarboxylic acid tris-({2-[(2-hydroxy-benzylidene)-amino]-ethyl}-amide (CYCOENSAL, L(1)) and cis-cis cyclohexane-1,3,5-tricarboxylic acid tris-({3-[(2-hydroxy-benzylidene)-amino]-propyl}-amide (CYCOPNSAL, L(2)) is described. Three protonation constants obtained are assigned for three hydroxyl groups of aromatic ring were employed for the evaluation of the formation constants of the metal complexes. Both ligands liberate three protons each forming monomeric complexes of type FeLH3, FeLH2, FeLH and FeL (L=L(1) and L(2)). The first species FeLH3 depicted at low pH, where the ligands were coordinated through three imine nitrogen and other species form subsequently from FeLH3 in steps upon deprotonation and coordination of the phenolic oxygen giving encapsulated tris(phenolate) complexes. The probable structures of the metal complexes formed in solution were proposed through molecular modeling calculations. L(2) was observed to be highly selective towards Fe(III) as compared to L(1).
authors.affiliation: Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal 148106, Punjab, India.
authors.forename: Rati Kanta
authors.initials: RK
authors.lastname: Bera
authors.affiliation: Department of Chemistry, National Institute of Technology, Kurukshetra, Haryana 136119, India.
authors.forename: Minati
authors.initials: M
authors.lastname: Baral
authors.affiliation: Department of Applied Chemistry, S.V. National Institute of Technology (SVNIT), Surat, Gujrat, India.
authors.forename: Suban K
authors.initials: SK
authors.lastname: Sahoo
authors.affiliation: Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal 148106, Punjab, India. Electronic address: b.kanungo@gmail.com.
authors.forename: B K
authors.initials: BK
authors.lastname: Kanungo
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D056831:Coordination Complexes; D003510:Cyclohexanes / Q000737:chemistry*; D055664:Electrochemical Techniques; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007097:Imines / Q000737:chemistry; D007502:Iron Chelating Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D008024:Ligands; D008956:Models, Chemical; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D011522:Protons; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001593:Benzyl Compounds; D056831:Coordination Complexes; D003510:Cyclohexanes; D005290:Ferric Compounds; D007097:Imines; D007502:Iron Chelating Agents; D008024:Ligands; D011522:Protons; C000601613:cyclohexane-1,3,5-tricarboxylic acid tris-((2-((2-hydroxy-benzylidene)-amino)-ethyl)-amide; C000601614:cyclohexane-1,3,5-tricarboxylic acid tris-((3-((2-hydroxy-benzylidene)-amino)-propyl)-amide; D009584:Nitrogen
keywords: Chelator; Imino-phenolate; Iron; Metal complex; Stability constant