Ground- and Excited-State Tautomerization Rates in Porphycenes
Article first published online: 23 MAR 2009
Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chemistry - A European Journal
Volume 15, Issue 19, pages 4851–4856, May 4, 2009
How to Cite
Fita, P., Urbańska, N., Radzewicz, C. and Waluk, J. (2009), Ground- and Excited-State Tautomerization Rates in Porphycenes. Chem. Eur. J., 15: 4851–4856. doi: 10.1002/chem.200802428
- Issue published online: 28 APR 2009
- Article first published online: 23 MAR 2009
- Manuscript Revised: 22 DEC 2008
- Manuscript Received: 21 NOV 2008
- polarization spectroscopy;
- proton transfer;
Reaction rates from polarized spectroscopy: A new method based on ultrafast pump–probe polarization spectroscopy enables the measurement of the ground- and excited-state reaction rates for self-exchange processes. The technique was used to study double hydrogen transfer in porphycene and its derivatives (see figure).
The rates of double hydrogen transfer in the ground and excited electronic states have been measured for porphycene and its derivatives by using a new method based on pump–probe polarization spectroscopy. Changing the strength of two intramolecular hydrogen bonds by altering the NH⋅⋅⋅N distance leads to differences in the tautomerization rate exceeding three orders of magnitude. The reaction is considerably slower in the lowest electronically excited state. A correlation was found between the tautomerization rates and 1H chemical shifts of the internal protons.