title: Characterization of photoproducts of m-THPP in aqueous solution.
abstract: This study examined the nature of photoproducts after pulse laser irradiation (647.5 nm) of 5,10,15,20-tetrakis(meso-hydroxyphenyl)porphyrin (m-THPP) (10 micromol/L) in ethanol-water (1/99, vol/vol) solution. Spectroscopic measurements (UV-visible absorption and fluorescence) and mass spectrometry techniques (matrix-assisted laser desorption-ionization [MALDI] coupled with time-of-flight mass spectrometer [TOF-MS] or tandem time of flight mass spectrometer [TOF/TOF-MS]) were used to follow photomodifications. Spectroscopic measurements evidenced photomodification as the main process after m-THPP irradiation. Three oxidized photoproducts at m/z 693.25, 695.24 and 713.25 were characterized by MS. After prolonged irradiation new isotopic distributions were registered at m/z 1355.41, 2031.57, 2707.80 and 3383.98 with MALDI-TOF-MS and TOF/TOF-MS. These new photoproducts were attributed to covalent oligomeric structures as dimer, trimer, tetramer and pentamer of m-THPP.
authors.affiliation: Laboratoire de Spectrométrie de Masse et de Chimie Laser (LSMCL), Université Paul Verlaine-Metz, Institut de Physique et d'Electronique de Metz (IPEM), Metz, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Lourette
authors.forename: Benoît
authors.initials: B
authors.lastname: Maunit
authors.forename: Lina
authors.initials: L
authors.lastname: Bezdetnaya
authors.forename: Henri-Pierre
authors.initials: HP
authors.lastname: Lassalle
authors.forename: François
authors.initials: F
authors.lastname: Guillemin
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Muller