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 Cold Protonated Cytosine Tautomers: Characterization of Charge Transfer, Intersystem Crossing, and Internal Conversion Processes

2017 ◽  
Vol 121 (34) ◽  
pp. 6429-6439 ◽  
Author(s):  
Michel Broquier ◽  
Satchin Soorkia ◽  
Gustavo Pino ◽  
Claude Dedonder-Lardeux ◽  
Christophe Jouvet ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Internal Conversion ◽  
Intersystem Crossing ◽  
Excited State Dynamics ◽  
Protonated Cytosine

scholarly journals Excited state dynamics of protonated keto uracil: intersystem crossing pathways in competition

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Jordan Dezalay ◽  
Michel Broquier ◽  
Satchin Soorkia ◽  
Gilles Grégoire
Keyword(s):  
Excited State ◽  
Intersystem Crossing ◽  
Excited State Dynamics

scholarly journals Visualizing excited state dynamics of conjugated molecules trough femtosecond stimulated Raman scattering

2019 ◽  
Vol 205 ◽  
pp. 09015
Author(s):  
Batignani Giovanni ◽  
Pontecorvo Emanuele ◽  
Ferrante Carino ◽  
Aschi Massimiliano ◽  
Elles Christopher G. ◽  
...  
Keyword(s):  
Excited State ◽  
Raman Scattering ◽  
Model Compound ◽  
Stimulated Raman Scattering ◽  
Reaction Pathway ◽  
Structural Rearrangement ◽  
Intersystem Crossing ◽  
Conjugated Molecules ◽  
Excited State Dynamics ◽  
Stimulated Raman

The reaction pathway in the photoexcited model compound 2-methyl-5-phenylthiophene has been unravelled by Femtosecond Stimulated Raman Scattering and quantum chemical calculations. The excited state dynamics, including structural rearrangement, vibrational cooling and intersystem-crossing, will be presented.

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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