Bimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ions

Handle URI:
http://hdl.handle.net/10754/576981
Title:
Bimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ions
Authors:
Alsam, Amani Abdu; Aly, Shawkat Mohammede ( 0000-0002-0455-1892 ) ; Usman, Anwar; Parida, Manas R.; Del Gobbo, Silvano; Alarousu, Erkki; Mohammed, Omar F. ( 0000-0001-8500-1130 )
Abstract:
We explored the excited-state interactions of bimolecular, non-covalent systems consisting of cationic poly[(9,9-di(3,3’-N,N’-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctyl-fluorenyl-2,7-diyl)] diiodide salt (PFN) and 1,4-dicyanobenzene (DCB) using steady-state and time-resolved techniques, including femto- and nanosecond transient absorption and femtosecond infrared spectroscopies with broadband capabilities. The experimental results demonstrated that photo-induced electron transfer from PFN to DCB occurs on the picosecond time scale, leading to the formation of PFN+• and DCB-• radical ions. Interestingly, real-time observations of the vibrational marker modes on the acceptor side provided direct evidence and insight into the electron transfer process indirectly inferred from UV-Vis experiments. The band narrowing on the picosecond time scale observed on the antisymmetric C-N stretching vibration of the DCB radical anion provides clear experimental evidence that a substantial part of the excess energy is channeled into vibrational modes of the electron transfer product and that the geminate ion pairs dissociate. More importantly, our nanosecond time-resolved data indicate that the charge-separated state is very long lived ( 30 ns) due to the dissociation of the contact radical ion pair into free ions. Finally, the fast electron transfer and slow charge recombination anticipate the current donor−acceptor system with potential applications in organic solar cells.
KAUST Department:
Solar and Photovoltaic Engineering Research Center (SPERC); Physical Sciences and Engineering (PSE) Division
Citation:
Bimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ions 2015:150902050947004 The Journal of Physical Chemistry C
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry C
Issue Date:
2-Sep-2015
DOI:
10.1021/acs.jpcc.5b06636
Type:
Article
ISSN:
1932-7447; 1932-7455
Additional Links:
http://pubs.acs.org/doi/10.1021/acs.jpcc.5b06636
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorAlsam, Amani Abduen
dc.contributor.authorAly, Shawkat Mohammedeen
dc.contributor.authorUsman, Anwaren
dc.contributor.authorParida, Manas R.en
dc.contributor.authorDel Gobbo, Silvanoen
dc.contributor.authorAlarousu, Erkkien
dc.contributor.authorMohammed, Omar F.en
dc.date.accessioned2015-09-09T05:45:54Zen
dc.date.available2015-09-09T05:45:54Zen
dc.date.issued2015-09-02en
dc.identifier.citationBimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ions 2015:150902050947004 The Journal of Physical Chemistry Cen
dc.identifier.issn1932-7447en
dc.identifier.issn1932-7455en
dc.identifier.doi10.1021/acs.jpcc.5b06636en
dc.identifier.urihttp://hdl.handle.net/10754/576981en
dc.description.abstractWe explored the excited-state interactions of bimolecular, non-covalent systems consisting of cationic poly[(9,9-di(3,3’-N,N’-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctyl-fluorenyl-2,7-diyl)] diiodide salt (PFN) and 1,4-dicyanobenzene (DCB) using steady-state and time-resolved techniques, including femto- and nanosecond transient absorption and femtosecond infrared spectroscopies with broadband capabilities. The experimental results demonstrated that photo-induced electron transfer from PFN to DCB occurs on the picosecond time scale, leading to the formation of PFN+• and DCB-• radical ions. Interestingly, real-time observations of the vibrational marker modes on the acceptor side provided direct evidence and insight into the electron transfer process indirectly inferred from UV-Vis experiments. The band narrowing on the picosecond time scale observed on the antisymmetric C-N stretching vibration of the DCB radical anion provides clear experimental evidence that a substantial part of the excess energy is channeled into vibrational modes of the electron transfer product and that the geminate ion pairs dissociate. More importantly, our nanosecond time-resolved data indicate that the charge-separated state is very long lived ( 30 ns) due to the dissociation of the contact radical ion pair into free ions. Finally, the fast electron transfer and slow charge recombination anticipate the current donor−acceptor system with potential applications in organic solar cells.en
dc.language.isoenen
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/10.1021/acs.jpcc.5b06636en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/10.1021/acs.jpcc.5b06636.en
dc.titleBimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ionsen
dc.typeArticleen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalThe Journal of Physical Chemistry Cen
dc.eprint.versionPost-printen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorAly, Shawkat Mohammedeen
kaust.authorUsman, Anwaren
kaust.authorParida, Manas R.en
kaust.authorDel Gobbo, Silvanoen
kaust.authorAlarousu, Erkkien
kaust.authorMohammed, Omar F.en
kaust.authorAlsam, Amani Abduen
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