title: Photophysical properties of 2-nitro-5,10,15,20-tetra-p-tolylporphyrins.
abstract: Tetraarylporphyrins substituted with nitro groups at beta-pyrrolic positions are potential candidates for electron-accepting pigments in model systems for photosynthesis. The photophysics of 2-nitro-5,10,15,20-tetra-p-tolylporphyrin and its zinc analog have been studied in order to evaluate this potential. The ground state absorption spectrum, the triplet-triplet absorption spectrum, the fluorescence emission spectrum, and associated photophysical parameters have been determined. The molecules have short singlet lifetimes and anomalous temperature- and solvent-dependent emission spectra which are consistent with the formation of an intramolecular charge transfer state of the type P+.-NO2-. in which the nitro group is twisted about its bond to the porphyrin, relative to the ground state conformation.
authors.affiliation: Department of Chemistry, Arizona State University, Tempe 85287-1604.
authors.forename: D
authors.initials: D
authors.lastname: Gust
authors.forename: T A
authors.initials: TA
authors.lastname: Moore
authors.forename: D K
authors.initials: DK
authors.lastname: Luttrull
authors.forename: G R
authors.initials: GR
authors.lastname: Seely
authors.forename: E
authors.initials: E
authors.lastname: Bittersmann
authors.forename: R V
authors.initials: RV
authors.lastname: Bensasson
authors.forename: M
authors.initials: M
authors.lastname: Rougée
authors.forename: E J
authors.initials: EJ
authors.lastname: Land
authors.forename: F C
authors.initials: FC
authors.lastname: De Schryver
authors.forename: M
authors.initials: M
authors.lastname: Van der Auweraer
mesh_terms: D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis*; D011166:Porphyrins / Q000138:chemical synthesis*; D011838:Radiation-Sensitizing Agents / Q000138:chemical synthesis*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013329:Structure-Activity Relationship
chemical_list: D009574:Nitro Compounds; D011166:Porphyrins; D011838:Radiation-Sensitizing Agents