PHOTOCHEMISTRY OF N-(PHOSPHONOMETHYL) GLYCINE IN THE PRESENCE OF FERRIC IONS

Ferric complex [Fe(gly)(2)](3-) (gly(3-) = anion of N-(phosphonomethyl )glycine) undergoes a photoredox transformation when being irradiated with UV radiation both in aqueous and methanolic media. Photoreduction of Fe(III) to Fe(II), occurring in deoxygenated systems, is accompani ed by decomposition of the coordinated ligand. As the products of this photodecomposition, formaldehyde, ammonia, and new phosphorus-contain ing species were identified in aqueous media. Along with the photoindu ced oxidation of the ligand, molecules of solvent are oxidized in meth anolic media as well. In the presence of oxygen no net Fe(III) reducti on is observed. Photochemical degradation of N-(phosphonomethyl)glycin e was monitored using P-31 NMR and electronic absorption spectroscopy. Attempts to rationalize the spectral changes and the mechanism of the photochemical processes are involved.