Excited-State Dynamics of 2-(2′-Hydroxyphenyl)benzothiazole: Ultrafast Proton Transfer and Internal Conversion

2017 ◽  
Vol 121 (24) ◽  
pp. 4595-4605 ◽  
Author(s):  
Shiela Pijeau ◽  
Donneille Foster ◽  
Edward G. Hohenstein
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Internal Conversion ◽  
Excited State Dynamics

The mechanism of excited-state proton transfer in 1-naphthol–piperidine clusters

2015 ◽  
Vol 17 (38) ◽  
pp. 25393-25402 ◽  
Author(s):  
Toshihiko Shimizu ◽  
Shun Manita ◽  
Shunpei Yoshikawa ◽  
Kenro Hashimoto ◽  
Mitsuhiko Miyazaki ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Internal Conversion ◽  
Conversion Process ◽  
Excited State Proton Transfer

Photoexcitation directly triggers proton transfer in 1-naphthol–(piperidine)n. This mechanism is essentially different from 1-naphthol–(NH3)n in which the internal conversion process is required to promote excited-state proton transfer.

Excited-state intramolecular proton transfer and conformational relaxation in 4′-N,N-dimethylamino-3-hydroxyflavone doped in acetonitrile crystals

2016 ◽  
Vol 18 (41) ◽  
pp. 28564-28575 ◽  
Author(s):  
Kazuki Furukawa ◽  
Norifumi Yamamoto ◽  
Kazuyuki Hino ◽  
Hiroshi Sekiya
Keyword(s):  
Excited State ◽  
Steady State ◽  
Fluorescence Spectroscopy ◽  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Conformational Relaxation ◽  
Excited State Dynamics

Excited-state dynamics of 4′-N,N-dimethylamino-3-hydroxyflavone doped in acetonitrile crystals has been investigated by using steady-state and time-resolved fluorescence spectroscopy.

Picosecond excited-state dynamics in octahedral cobalt(III) complexes: intersystem crossing versus internal conversion

1993 ◽  
Vol 32 (4) ◽  
pp. 394-399 ◽  
Author(s):  
James K. McCusker ◽  
Kevin N. Walda ◽  
Douglas Magde ◽  
David N. Hendrickson
Keyword(s):  
Excited State ◽  
Internal Conversion ◽  
Intersystem Crossing ◽  
Excited State Dynamics

scholarly journals Excited State Dynamics of 7-Deazaguanosine and Guanosine 5’ Monophosphate in Aqueous Solution

2020 ◽  
Author(s):  
Sarah E. Krul ◽  
Sean J. Hoehn ◽  
Karl Feierabend ◽  
Carlos Crespo-Hernández
Keyword(s):  
Aqueous Solution ◽  
Excited State ◽  
Potential Energy Surfaces ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Relaxation Mechanism ◽  
Transient Absorption Spectroscopy ◽  
Experimental Conditions ◽  
Excited State Dynamics ◽  
Computational Calculations

Minor structural modifications to the DNA and RNA nucleobases have a significant effect on their excited state dynamics and electronic relaxation pathways.<b> </b>In this study, the excited state dynamics of 7-deazaguanosine and guanosine 5’-monophosphate are investigated in aqueous solution using femtosecond broadband transient absorption spectroscopy following excitation at 267 nm. The transient absorption spectra are collected under experimental conditions that eliminate the requirement to correct the data for the formation of hydrated electrons, resulting from the two-photon ionization of the solvent. The data is fitted satisfactorily using a two-component sequential kinetic model, yielding lifetimes of 210 ± 50 fs and 1.80 ± 0.02 ps, and 682 ± 40 fs and 1.4 ± 0.03 ps, for 7-deazaguanosine and guanosine 5’-monophosphate, respectively. By analyzing the results from steady-state, time-resolved, and computational calculations, the following relaxation mechanism is proposed for 7-deazaguanosine, S<sub>2</sub>(L<sub>b</sub>) ® S<sub>1</sub>(L<sub>a</sub>) ® S<sub>0</sub>, whereas a S<sub>2</sub>(L<sub>b</sub>) ® S<sub>1</sub>(L<sub>a</sub>) ® S<sub>0</sub>(hot)<sub> </sub>® S<sub>0 </sub>relaxation mechanism<sub> </sub>is proposed for guanosine 5’-monophosphate. Interestingly, longer lifetimes for both the L<sub>b</sub> ® L<sub>a</sub> and the L<sub>a</sub> ® S<sub>0</sub> internal conversion pathways are obtained for 7-deazaguanosine compare to guanosine 5’-monophosphate. Collectively, the results demonstrate that substitution of a single nitrogen for a methine (C-H) group at position seven of the guanine moiety stabilizes the <sup>1</sup>pp* L<sub>b</sub> and L<sub>a</sub> states and alters the topology of their potential energy surfaces in such a way that the population dynamics of both internal conversion pathways in 7-deazaguanosine are significantly slowed down compared to those in guanosine 5’-monophosphate.

Symmetry controlled excited state dynamics

2019 ◽  
Vol 21 (5) ◽  
pp. 2283-2294 ◽  
Author(s):  
Max D. J. Waters ◽  
Anders B. Skov ◽  
Martin A. B. Larsen ◽  
Christian M. Clausen ◽  
Peter M. Weber ◽  
...  
Keyword(s):  
Excited State ◽  
Internal Conversion ◽  
Rydberg States ◽  
Aliphatic Amines ◽  
Velocity Map Imaging ◽  
Excited State Dynamics ◽  
Loss Of Coherence

Symmetry effects in internal conversion are studied by means of two isomeric cyclic tertiary aliphatic amines in a velocity map imaging (VMI) experiment on the femtosecond timescale. We conclude that lessening the symmetry of the molecule leads to loss of coherence after internal conversion between Rydberg states.

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