title: Time resolved fluorescence spectroscopy of Eu(III) complexation with alpha-hydroxy isobutyric acid.
abstract: Complexation of Eu(III) with alpha-hydroxy isobutyric acid (HIBA), a model compound of humic acid, has been studied by time resolved fluorescence spectroscopy. The ratio of fluorescence intensity of the two peaks at 616 and 592 nm (I(616/592)) was found to increase with increasing ligand to metal ratio. The I(616/592) data was used to deduce the stability constant of Eu-HIBA complexes of the type ML(i) (i=1-3). The formation of multiple ligand complexes was also corroborated by lifetime data which was found to increase with increasing [HIBA]/[Eu] ratio thus indicating replacement of coordinated water molecules by HIBA.
authors.affiliation: Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: A
authors.initials: A
authors.lastname: Jain
authors.forename: M
authors.initials: M
authors.lastname: Mohapatra
authors.forename: S V
authors.initials: SV
authors.lastname: Godbole
authors.forename: B S
authors.initials: BS
authors.lastname: Tomar
mesh_terms: D005063:Europium / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D006885:Hydroxybutyrates / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry
chemical_list: D006812:Humic Substances; D006885:Hydroxybutyrates; D008024:Ligands; D009942:Organometallic Compounds; D012996:Solutions; D014867:Water; D005063:Europium; C008039:2-hydroxyisobutyric acid