We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Excited-state dynamics of deuterated indigo.
- Authors
Cohen, Trevor; Svadlenak, Nathan; Smith, Charles; Vo, Krystal; Lee, Si-Young; Parejo-Vidal, Ana; Kincaid, Joseph R. A.; Sobolewski, Andrzej L.; Rode, Michal F.; de Vries, Mattanjah S.
- Abstract
Indigo, a rich blue dye, is an incredibly photostable molecule that has survived in ancient art for centuries. It is also unique in that it can undergo both an excited-state hydrogen and proton transfer on the picosecond timescale followed by a ground-state back transfer. Previously, we performed gas phase excited-state lifetime studies on indigo to study these processes in a solvent-free environment, combined with excited-state calculations. We found two decay pathways, a fast sub-nanosecond decay and a slow decay on the order of 10 ns. Calculations of the excited-state potential energy surface found that both hydrogen and proton transfer are nearly isoenergetic separated by a 0.1 eV barrier. To further elucidate these dynamics, we now report a study with deuterated indigo, using resonance-enhanced multi-photon ionization and pump-probe spectroscopy with mass spectrometric isotopomer selection. From new calculations of the excited-state potential energy surface, we find sequential double-proton or hydrogen transfer, whereby the trajectory to the second transfer passes a second barrier and then encounters a conical intersection that leads back to the ground state. We find that deuteration only increases the excited-state lifetimes of the fast decay channel, suggesting tunneling through the first barrier, while the slower channel is not affected and may involve a different intermediate state.
- Subjects
INTRAMOLECULAR proton transfer reactions; POTENTIAL energy surfaces; MULTIPHOTON ionization; PROTON transfer reactions; MASS spectrometry; ANCIENT art; QUANTUM tunneling; ORBITAL transfer (Space flight)
- Publication
European Physical Journal D (EPJ D), 2023, Vol 77, Issue 9, p1
- ISSN
1434-6060
- Publication type
Article
- DOI
10.1140/epjd/s10053-023-00744-z