Copper complexes immobilized to chitosan.
Polymeric ligands, such as 2-substituted pentanedioic acid (2), 2-substituted propanoic acid (3), and deoxylactit-1-yl (4) derivatives of chitosan (1), were used to prepare copper complexes that are widely soluble in aqueous solution. EPR results (100 K) show that all association complexes basically have a tetragonal symmetry. Visible CD spectra suggest, however, that the order of increasing departure from this geometry is Cu-(1) approximately Cu-(3) less than Cu-(2) less than or equal to Cu-(4), the lack of sterically constraining side-chains in (1) and (3) allowing a more symmetric arrangement of ligands around the central metal ion. Results on the catalytic activity of the association complexes for air oxidation of catechol derivatives are also presented.
Chiessi
E
E
Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Italy.
Paradossi
G
G
Venanzi
M
M
Pispisa
B
B
D002384:Catalysis; D002614:Chelating Agents; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D048271:Chitosan; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D004837:Epinephrine / Q000378:metabolism; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012995:Solubility; D012996:Solutions
D002614:Chelating Agents; D012996:Solutions; D002686:Chitin; D003300:Copper; D048271:Chitosan; D004837:Epinephrine