title: Photogeneration of titanium(III) from titanium(IV) citrate in aqueous solution.
abstract: Current interest in the biochemistry of Ti(IV) arises from its widespread use in white pigments and its potential in therapeutic agents. Citrate is known to form strong complexes with Ti(IV). We show here that Ti(III) citrate is generated in a facile manner and in good yield by the action of UV radiation on Ti(IV) citrate in aqueous solution. The Ti(III)-citrate species formed was isolated and characterised by UV-Visible spectroscopy, showing an absorption at 547 nm (epsilon=100 M(-1)cm(-1)), and by electron paramagnetic resonance (EPR) spectroscopy giving a resonance at g=1.949 (linewidth=60G) . An X-ray structure of the parent Ti(IV) complex in the form [TiNa(3)(C(6)H(6)O(7))(2)(C(6)H(5)O(7))(H(2)O)(6.8)].2H(2)O is reported along with a study of the reaction of Ti(IV)-citrate with N,N-ethylenebis(o-hydroxytoluene)glycine (EHTG), which was more rapid than those of other related Ti(IV) complexes.
authors.affiliation: School of Chemistry, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: Paradies
authors.forename: Jane
authors.initials: J
authors.lastname: Crudass
authors.forename: Fiona
authors.initials: F
authors.lastname: Mackay
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Yellowlees
authors.forename: James
authors.initials: J
authors.lastname: Montgomery
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
authors.forename: Iain
authors.initials: I
authors.lastname: Oswald
authors.forename: Neil
authors.initials: N
authors.lastname: Robertson
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sadler
mesh_terms: D019343:Citric Acid / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D008958:Models, Molecular; D010777:Photochemistry; D012996:Solutions; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; C419387:titanium citrate; D014867:Water; D019343:Citric Acid; D014025:Titanium