%0 Journal Article %1 ruetzel2014photoisomerization %A Ruetzel, Stefan %A Diekmann, Meike %A Nuernberger, Patrick %A Walter, Christof %A Engels, Bernd %A Brixner, Tobias %B The Journal of Chemical Physics %D 2014 %I American Institute of Physics %J J. Chem. Phys. %K Engels myown %N 22 %P 224310-- %R 10.1063/1.4881258 %T Photoisomerization among ring-open merocyanines. I. Reaction dynamics and wave-packet oscillations induced by tunable femtosecond pulses %U https://doi.org/10.1063/1.4881258 %V 140 %X Upon ultraviolet excitation, photochromic spiropyran compounds can be converted by a ring-opening reaction into merocyanine molecules, which in turn can form several isomers differing by cis and trans configurations in the methine bridge. Whereas the spiropyran–merocyanine conversion reaction of the nitro-substituted indolinobenzopyran 6-nitro-1′,3′,3′-trimethylspiro2H-1-benzopyran-2,2′-indoline (6-nitro BIPS) has been studied extensively in theory and experiments, little is known about photoisomerization among the merocyanine isomers. In this article, we employ femtosecond transient absorption spectroscopy with variable excitation wavelengths to investigate the excited-state dynamics of the merocyanine in acetonitrile at room temperature, where exclusively the trans-trans-cis (TTC) and trans-trans-trans (TTT) isomers contribute. No photochemical ring-closure pathways exist for the two isomers. Instead, we found that (18±4)% of excited TTC isomers undergo an ultrafast excited-state cis→trans photoisomer...

@article{ruetzel2014photoisomerization, abstract = {Upon ultraviolet excitation, photochromic spiropyran compounds can be converted by a ring-opening reaction into merocyanine molecules, which in turn can form several isomers differing by cis and trans configurations in the methine bridge. Whereas the spiropyran–merocyanine conversion reaction of the nitro-substituted indolinobenzopyran 6-nitro-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indoline] (6-nitro BIPS) has been studied extensively in theory and experiments, little is known about photoisomerization among the merocyanine isomers. In this article, we employ femtosecond transient absorption spectroscopy with variable excitation wavelengths to investigate the excited-state dynamics of the merocyanine in acetonitrile at room temperature, where exclusively the trans-trans-cis (TTC) and trans-trans-trans (TTT) isomers contribute. No photochemical ring-closure pathways exist for the two isomers. Instead, we found that (18±4)% of excited TTC isomers undergo an ultrafast excited-state cis→trans photoisomer...}, added-at = {2019-02-25T17:22:08.000+0100}, author = {Ruetzel, Stefan and Diekmann, Meike and Nuernberger, Patrick and Walter, Christof and Engels, Bernd and Brixner, Tobias}, biburl = {https://www.bibsonomy.org/bibtex/221370e96d396b38ab07542860cbd20f5/akengels}, booktitle = {The Journal of Chemical Physics}, comment = {doi: 10.1063/1.4881258}, doi = {10.1063/1.4881258}, interhash = {db22af2764961f0bd05750c3d9a2644f}, intrahash = {21370e96d396b38ab07542860cbd20f5}, issn = {00219606}, journal = {J. Chem. Phys.}, keywords = {Engels myown}, month = jun, number = 22, pages = {224310--}, publisher = {American Institute of Physics}, timestamp = {2019-02-25T17:22:08.000+0100}, title = {Photoisomerization among ring-open merocyanines. I. Reaction dynamics and wave-packet oscillations induced by tunable femtosecond pulses}, url = {https://doi.org/10.1063/1.4881258}, volume = 140, year = 2014 }