Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes
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...
Guardado en:
Autores principales: | , , , , |
---|---|
Formato: | Artículo publishedVersion |
Publicado: |
1990
|
Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00223654_v94_n15_p5879_Nonell_oai |
Aporte de: |
id |
I28-R145-paper_00223654_v94_n15_p5879_Nonell_oai |
---|---|
record_format |
dspace |
spelling |
I28-R145-paper_00223654_v94_n15_p5879_Nonell_oai2020-10-19 Nonell, S. Aramendía, P.F. Heihoff, K. Negri, R.M. Braslavsky, S.E. 1990 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. application/pdf http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Journal of Physical Chemistry 1990;94(15):5879-5883 Laser-induced optoacoustics combined with near-infrared emission. An alternative approach for the determination of intersystem crossing quantum yields applied to porphycenes info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00223654_v94_n15_p5879_Nonell_oai |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-145 |
collection |
Repositorio Digital de la Universidad de Buenos Aires (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 |
Artículo Artículo publishedVersion |
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 |
publishDate |
1990 |
url |
http://hdl.handle.net/20.500.12110/paper_00223654_v94_n15_p5879_Nonell http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00223654_v94_n15_p5879_Nonell_oai |
work_keys_str_mv |
AT nonells laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes AT aramendiapf laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes AT heihoffk laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes AT negrirm laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes AT braslavskyse laserinducedoptoacousticscombinedwithnearinfraredemissionanalternativeapproachforthedeterminationofintersystemcrossingquantumyieldsappliedtoporphycenes |
_version_ |
1766026604645974016 |