Ultrafast Intramolecular Charge Transfer of Formyl Perylene Observed Using Femtosecond Transient Absorption Spectroscopy
- Creators
- Mohammed, Omar F.
Abstract
The excited-state photophysics of formylperylene (FPe) have been investigated in a series of nonpolar, polar aprotic, and polar protic solvents. A variety of experimental and theoretical methods were employed including femtosecond transient absorption (fs-TA) spectroscopy with 130 fs temporal resolution. We report that the ultrafast intramolecular charge transfer from the perylene unit to the formyl (CHO) group can be facilitated drastically by hydrogen-bonding interactions between the carbonyl group oxygen of FPe and hydrogen-donating solvents in the electronically excited state. The excited-state absorption of FPe in methanol (MeOH) is close to the reported perylene radical cation produced by bimolecular quenching by an electron acceptor. This is a strong indication for a substantial charge transfer in the S1 state in protic solvents. The larger increase of the dipole moment change in the protic solvents than that in aprotic ones strongly supports this observation. Relaxation mechanisms including vibrational cooling and solvation coupled to the charge-transfer state are also discussed.
Additional Information
© 2010 American Chemical Society. Received: August 2, 2010; Revised Manuscript Received: September 10, 2010; Published on Web 10/01/2010. I thank Professor Tahei Tahara and Dr. Satoshi Takeuchi for their assistance and useful discussions on the time-resolved experiments which have been done at RIKEN and the Japan Society for Promotion of Science (JSPS). This paper was written while the author performed research at Caltech (supported by the NSF and the Arab fund) in the Physical Biology Center for Ultrafast Science and Technology. I thank Professor Ahmed H. Zewail for helpful comments and checking of the manuscript. I am extremely grateful for the support provided by the Arab Fund for Economic and Social Development through its distinguished scholar award.Additional details
- Eprint ID
- 21147
- Resolver ID
- CaltechAUTHORS:20101203-101000313
- NSF
- Arab Fund for Economic and Social Development
- Created
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2010-12-03Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field