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Characterization of Photoproducts of m ‐THPP in Aqueous Solution ¶
Author(s) -
Lourette Natacha,
Maunlt Benoît,
Bezdetnaya Lina,
Lassalle HenriPierre,
Guillemin Françols,
Muller JeanFrançois
Publication year - 2005
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2005.tb00245.x
Subject(s) - mass spectrometry , chemistry , trimer , pentamer , time of flight mass spectrometry , irradiation , porphyrin , tetramer , aqueous solution , dimer , tandem mass spectrometry , analytical chemistry (journal) , photochemistry , nuclear chemistry , ionization , chromatography , ion , organic chemistry , biochemistry , physics , enzyme , nuclear physics
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 μmol/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.