Premium
Time‐Resolved Thermal Lensing Studies on Metastable Species
Author(s) -
Cheng ChungChih,
Wu GuoRay,
Chiou ChauShuen,
Yu JenKan,
Chou PiTai
Publication year - 2003
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200300004
Subject(s) - chemistry , metastability , tautomer , relaxation (psychology) , quantum yield , aqueous solution , chemical physics , photochemistry , singlet oxygen , quenching (fluorescence) , thermal , singlet state , proton , yield (engineering) , oxygen , excited state , fluorescence , atomic physics , thermodynamics , organic chemistry , optics , social psychology , physics , psychology , quantum mechanics
Time‐resolved thermal lensing (TRTL) techniques have been applied to resolve photophysical and thermodynamic parameters for various metastable species, of which the relaxation dynamics are dominated by the radiationless transition. Using 1H‐phenalen‐1‐one as a sensitizer, the lifetime (τ Δ ), absolute quantum yield (Φ Δ ) and efficiency of generation ( S T Δ ) of singlet molecular oxygen ( 1 Δ g ) have been determined in various organic solvents. In particular, through the development of an ultrasensitive detecting system, TRTL studies on the relaxation dynamics of O 2 ( 1 Δ g ) become feasible in aqueous solution. In another application, based on the TRTL technique in combination with the O 2 sensitization experiment, the T 1 ‐S 0 energy gap of the proton‐transfer tautomer in 3‐hydroxyflavone, which is otherwise inaccessible due to the dominant radiationless deactivation, has been deduced to be ∼ 8500 ± 1020 cm −1 .