Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes

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An approach was developed to determine triplet quantum yields, ΦT, which overcomes most of the difficulties usually encountered in flash photolysis studies of triplet states. The combined application of near-IR emission and optoacoustics yields ΦT values which are independent of the absorption prope...

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Autores principales: Nonell, S., Aramendía, P.F., Heihoff, K., Negri, R.M., Braslavsky, S.E.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00223654_v94_n15_p5879_Nonell2023-10-03T14:32:11Z Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes Nonell, S. Aramendía, P.F. Heihoff, K. Negri, R.M. Braslavsky, S.E. An approach was developed to determine triplet quantum yields, ΦT, which overcomes most of the difficulties usually encountered in flash photolysis studies of triplet states. The combined application of near-IR emission and optoacoustics yields ΦT values which are independent of the absorption properties of the triplets. Thus, the triplet energies derived from near-IR phosphorescence spectra together with the values of the heat stored by the triplets determined from optoacoustic experiments afforded ΦT = 0.3 ± 0.1 for porphycene (PO) and 0.4 ± 0.1 for its tetra-n-propyl derivative (TPrPO). Several calorimetric references for optoacoustic measurements in the red region were tested. The ΦT values, combined with flash photolysis data, yielded accurate triplet- minus ground-state absorption coefficients. The quantum yields for singlet molecular oxygen production determined by time-resolved phosphorescence were ΦΔ = 0.34 ± 0.05 for PO and 0.36 ± 0.03 for TPrPO which implies an efficiency near unity for O2(1Δ8) production upon collision of the triplet states of the porphycenes with ground-state O2. © 1990 American Chemical Society. Fil:Aramendía, P.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Negri, R.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Braslavsky, S.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description An approach was developed to determine triplet quantum yields, ΦT, which overcomes most of the difficulties usually encountered in flash photolysis studies of triplet states. The combined application of near-IR emission and optoacoustics yields ΦT values which are independent of the absorption properties of the triplets. Thus, the triplet energies derived from near-IR phosphorescence spectra together with the values of the heat stored by the triplets determined from optoacoustic experiments afforded ΦT = 0.3 ± 0.1 for porphycene (PO) and 0.4 ± 0.1 for its tetra-n-propyl derivative (TPrPO). Several calorimetric references for optoacoustic measurements in the red region were tested. The ΦT values, combined with flash photolysis data, yielded accurate triplet- minus ground-state absorption coefficients. The quantum yields for singlet molecular oxygen production determined by time-resolved phosphorescence were ΦΔ = 0.34 ± 0.05 for PO and 0.36 ± 0.03 for TPrPO which implies an efficiency near unity for O2(1Δ8) production upon collision of the triplet states of the porphycenes with ground-state O2. © 1990 American Chemical Society.
format JOUR
author Nonell, S.
Aramendía, P.F.
Heihoff, K.
Negri, R.M.
Braslavsky, S.E.
spellingShingle Nonell, S.
Aramendía, P.F.
Heihoff, K.
Negri, R.M.
Braslavsky, S.E.
Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
author_facet Nonell, S.
Aramendía, P.F.
Heihoff, K.
Negri, R.M.
Braslavsky, S.E.
author_sort Nonell, S.
title Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
title_short Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
title_full Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
title_fullStr Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
title_full_unstemmed Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
title_sort laser-induced optoacoustics combined with near-infrared emission. an alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
url http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell
work_keys_str_mv AT nonells laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes
AT aramendiapf laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes
AT heihoffk laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes
AT negrirm laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes
AT braslavskyse laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes
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