Multistate photo-induced relaxation and photoisomerization ability of fumaramide threads: A computational and experimental study
| Autor: | Wybren Jan Buma, Daniel Shaw, Natalia Haraszkiewicz, G. Orlandi, Piet G. Wiering, Sander Woutersen, Francesco Zerbetto, Albert M. Brouwer, Grzegorz Balkowski, Céline Frochot, Marco Garavelli, Piero Altoè, Francesco G. Gatti, David A. Leigh |
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| Přispěvatelé: | Dipartimento di Chimica 'G. Ciamician', Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Van't Hoff Institute for Molecular Sciences, University of Amsterdam [Amsterdam] (UvA), Département de Chimie Physique des Réactions (DCPR), Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), The School of Chemistry, University of Edinburgh, P. Alto, N. Haraszkiewicz, F. G. Gatti, P. G. Wiering, C. Frochot, A. M. Brouwer, G. Balkowski, D. Shaw, S. Woutersen, W. J. Buma, F. Zerbetto, G. Orlandi, D. A. Leigh, M. Garavelli, Spectroscopy and Photonic Materials (HIMS, FNWI), Molecular Spectroscopy (HIMS, FNWI) |
| Rok vydání: | 2009 |
| Předmět: |
Photoisomerization
010405 organic chemistry Chemistry Relaxation (NMR) General Chemistry 010402 general chemistry Ring (chemistry) Photochemistry Internal conversion (chemistry) 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Colloid and Surface Chemistry Intersystem crossing Computational chemistry Picosecond Singlet state [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] Isomerization |
| Zdroj: | Journal of the American Chemical Society Journal of the American Chemical Society, American Chemical Society, 2008, 131, pp.104-117. ⟨10.1021/ja802531j⟩ Journal of the American Chemical Society, 131(1), 104-117. American Chemical Society |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja802531j |
| Popis: | Fumaric and maleic amides are the photoactive units of an important and widely investigated class of photocontrollable rotaxanes as they trigger ring shuttling via a cis−trans photoisomerization. Here, ultrafast decay and photoinduced isomerization in isolated fumaramide and solvated nitrogen-substituted fumaramides (that are employed as threads in those rotaxanes) have been investigated by means of CASPT2//CASSCF computational and time-resolved spectroscopic techniques, respectively. A complex multistate network of competitive deactivation channels, involving both internal conversion and intersystem crossing (ISC) processes, has been detected and characterized that accounts for the picosecond decay and photochemical/photophysical properties observed in the singlet as well as triplet (photosensitized) photochemistry of fumaramides threads. Interestingly, singlet photochemistry appears to follow a non-Kasha rule model, where nonequilibrium dynamical factors control the outcome of the photochemical process: accessible high energy portions of extended crossing seams turn out to drive the deactivation process and ground-state recovery. Concurrently, extended singlet/triplet degenerate regions of twisted molecular structures with significant spin−orbit-coupling values account for ultrafast (picosecond time scale) ISC processes that lead to higher photoisomerization efficiencies. This model discloses the principles behind the intrinsic photochemical reactivity of fumaramide and its control. |
| Databáze: | OpenAIRE |
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