title: Photophysics of soret-excited tin(IV) porphyrins in solution.
abstract: The photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as solvated monomers, and its Soret-excited S2 state in these solvents exhibits the expected linear energy gap law relationship with first-order population decay times in the 0.8 to 1.7 ps range. Evidence is presented that this metalloporphyrin aggregates in other solvents at the concentrations typically used for these ultrafast measurements and yields species-averaged time-resolved data. Cw laser excitation in the Q-band under deaerated conditions produces weak S2-S0 fluorescence (photon upconversion) as a result of triplet-triplet annihilation.
authors.affiliation: School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Ghiggino
authors.forename: Neeraj Kumar
authors.initials: NK
authors.lastname: Giri
authors.forename: Jordan
authors.initials: J
authors.lastname: Hanrieder
authors.forename: Jonathon D
authors.initials: JD
authors.lastname: Martell
authors.forename: Jens
authors.initials: J
authors.lastname: Müller
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Paige
authors.forename: Benjamin
authors.initials: B
authors.lastname: Robotham
authors.forename: Jędrzej
authors.initials: J
authors.lastname: Szmytkowski
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Steer
mesh_terms: D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D014001:Tin / Q000737:chemistry*
chemical_list: D008665:Metalloporphyrins; D012996:Solutions; D014001:Tin