title: Metal-carboxylate interactions in metal-alginate complexes studied with FTIR spectroscopy.
abstract: FTIR spectroscopy was used in order to obtain information about metal-carboxylate interactions in metal-alginate complexes of alginic acid and sodium alginate from the brown algae Laminaria digitata after crosslinking with Ca(2+), Cu(2+), Cd(2+), Zn(2+), Ni(2+) and Pb(2+). From the frequencies of the characteristic peaks for asymmetric COO stretching vibration (nu(asym)(COO(-)) and symmetric COO stretching vibration (nu(sym)(COO(-))) a 'pseudo bridged' unidentate coordination with intermolecular hydrogen bonds is proposed for the metal-carboxylate complexes in polyguluronic regions while for the polymannuronic regions the bidentate bridging coordination was proposed. The PIB factor introduced previously as a relationship between metal sorption and frequencies of the asymmetric vibrations was found not to correlate with sorption capacity or any other physical property of the metal-alginate complexes studied.
authors.affiliation: Institute of Physical Chemistry, N.C.S.R. Demokritos, Ag. Paraskevi Attikis, Greece. spap@chem.demokritos.gr
authors.forename: Sergios K
authors.initials: SK
authors.lastname: Papageorgiou
authors.forename: Evangelos P
authors.initials: EP
authors.lastname: Kouvelos
authors.forename: Evangelos P
authors.initials: EP
authors.lastname: Favvas
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Sapalidis
authors.forename: George E
authors.initials: GE
authors.lastname: Romanos
authors.forename: Fotios K
authors.initials: FK
authors.lastname: Katsaros
mesh_terms: D000042:Absorption; D000464:Alginates / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006860:Hydrogen Bonding; D007795:Laminaria / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014732:Vibration
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D008670:Metals; D009942:Organometallic Compounds; D011135:Polysaccharides, Bacterial; C111091:polyguluronic acid; D020723:Glucuronic Acid