CONFERENCE PROCEEDINGS
Advanced Search
Home > Proceedings > Volume 2370 > Article
Paper
2 January 1995 Energy and electron transfer processes in polymethine dyes
Karl-Heinz Feller
Author Affiliations +
Proceedings Volume 2370, 5th International Conference on Laser Applications in Life Sciences; (1995) https://doi.org/10.1117/12.197445
Event: Laser Applications in Life Sciences: 5th International Conference, 1994, Minsk, Belarus
Abstract
Polymethine dyes and its derivatives are attractive for their interesting optical and photo- electric properties. In the case of a polymethine which does not isomerize we were able to show by means of time-resolved absorption spectroscopy that the singlet state photoelectron transfer to methyl- and benzylviologen had an efficiency of 0.15 with rate constants of 6.7 (DOT) 109 and 4.6 (DOT) 109 l/mole(DOT)s, respectively, yielding the polymethine dication radical. The photo-reduction with tetraphenylborate and potassium rhodanide is also very efficient with an efficiency of about 0.10 with rate constants of 2.4 (DOT) 1010 and 1.6 (DOT) 1010 l/mole(DOT)s, respectively, yielding the polymethine neutral radical. The spectral differences of the observed radical spectra are small. The investigation of the temperature dependence of the photo induced electron transfer of the investigated polymethine to methylviologen results in an activation energy (Delta) G* equals 24 kJ/mole and a value of the frequency factor of A equals 4.7 (DOT) 1014 l/mole(DOT)s. Strong deviation from a linear Arrhenius plot was observed at low temperatures which can be explained by solvent-solute interaction decreasing the electron transfer rate constant at lower temperatures. The calculated electron transfer rate constants agree with the assumption of the investigated process as a diffusion-controlled one. We have investigated the time and spectral evolution of the energy transfer process from a polymethine dye to different energy acceptor dyes in solution as well as in Langmuir-Blodgett layers. The general question within this respect was the involvement of an intermediate electron transfer as competitive process in the energy transfer process.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation Download Citation
Karl-Heinz Feller "Energy and electron transfer processes in polymethine dyes", Proc. SPIE 2370, 5th International Conference on Laser Applications in Life Sciences, (2 January 1995); https://doi.org/10.1117/12.197445
ACCESS THE FULL ARTICLE
ORGANIZATIONAL
Sign in with credentials provided by your organization.
INSTITUTIONAL
Select your institution to access the SPIE Digital Library.
SELECT YOUR INSTITUTION
PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.
PERSONAL SIGN IN
No SPIE Account? Create one
PURCHASE THIS CONTENT
SUBSCRIBE TO DIGITAL LIBRARY
50 downloads per 1-year subscription
Members: $195
Non-members: $335 ADD TO CART
25 downloads per 1 - year subscription
Members: $145
Non-members: $250 ADD TO CART
PURCHASE SINGLE ARTICLE
Includes PDF, HTML & Video, when available
Members: $17.00
Non-members: $21.00 ADD TO CART
PROCEEDINGS
 13 PAGES
DOWNLOAD PAPER SAVE TO MY LIBRARY
GET CITATION
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Absorption
Energy transfer
Picosecond phenomena
Molecules
Life sciences
Luminescence
Laser applications
RELATED CONTENT
Subscribe to Digital Library
Receive Erratum Email Alert
Back to Top