Observing ground state vibrational coherence and excited state relaxation dynamics of a cyanine dye in pure solvents

2018 ◽  
Vol 20 (19) ◽  
pp. 13400-13411 ◽  
Author(s):  
Dipak Kumar Das ◽  
Krishnandu Makhal ◽  
Debabrata Goswami
Keyword(s):  
Excited State ◽  
Ground State ◽  
Cyanine Dye ◽  
Relaxation Dynamics ◽  
Pump Probe ◽  
Probe Technique ◽  
Vibrational Coherence

Using a degenerate pump probe technique at 800 nm, Ground State Vibrational Coherence (GSVC) of a cyanine dye (IR780) is explored in various solvents.

Excited State Absorption in Pr3+ Doped Fluorozirconate Glass

1991 ◽  
Vol 244 ◽  
Author(s):  
R. S. Quimby ◽  
B. Zheng
Keyword(s):  
Excited State ◽  
Excited State Absorption ◽  
Fiber Amplifier ◽  
Pump Probe ◽  
Probe Technique ◽  
Zblan Glass ◽  
Fluorozirconate Glass ◽  
A New Technique ◽  
Doped Glass ◽  
Good Agreement

ABSTRACTThe excited state absorption (ESA) spectrum for Pr3+ doped ZBLAN glass is determined using a new technique based on the McCumber theory [D.E. McCumber, Phys. Rev. 136, A954 (1964)]. ESA peaks at 1380 and 840 nm are found, corresponding to transitions from the 1G4 to the 1D2 and 1I6 levels, respectively. ESA at the fiber amplifier pump wavelength 1.017 μm is found to be very small. The new method is also applied to Er+ doped glass, and good agreement is obtained between the resulting ESA spectrum and previous measurements using a traditional pump-probe technique.

Bringing light into the dark triplet space of molecular systems

2015 ◽  
Vol 17 (19) ◽  
pp. 13129-13136 ◽  
Author(s):  
Jing Ge ◽  
Qun Zhang ◽  
Jun Jiang ◽  
Zhigang Geng ◽  
Shenlong Jiang ◽  
...  
Keyword(s):  
Excited State ◽  
Pump Probe ◽  
Probe Technique ◽  
Excited State Dynamics ◽  
Molecular Systems

A novel pump–probe technique is developed to map out the excited-state dynamics in the triplet space of molecular systems.

scholarly journals A wavelength dependent investigation of the indole photophysics via ionization and fragmentation pump–probe spectroscopies

2015 ◽  
Vol 17 (38) ◽  
pp. 25197-25209 ◽  
Author(s):  
T. J. Godfrey ◽  
Hui Yu ◽  
Michael S. Biddle ◽  
Susanne Ullrich
Keyword(s):  
Excited State ◽  
Gas Phase ◽  
Spectroscopic Techniques ◽  
Relaxation Dynamics ◽  
Pump Probe ◽  
State Involvement

Using a variety of gas-phase pump–probe spectroscopic techniques, this work investigates indole excited-state relaxation dynamics at several pump wavelengths with a particular focus on 1πσ*-state involvement.

Excited-State Vibrational Coherence in Perylene Bisimide Probed by Femtosecond Broadband Pump–Probe Spectroscopy

2015 ◽  
Vol 119 (24) ◽  
pp. 6275-6282 ◽  
Author(s):  
Minjung Son ◽  
Kyu Hyung Park ◽  
Min-Chul Yoon ◽  
Pyosang Kim ◽  
Dongho Kim
Keyword(s):  
Excited State ◽  
Pump Probe ◽  
Vibrational Coherence ◽  
Perylene Bisimide ◽  
Probe Spectroscopy

Monitoring the Formation and Decay of Transient Photosensitized Intermediates Using Pump-Probe UV Resonance Raman Spectroscopy. I: Self-Modeling Curve Resolution

2003 ◽  
Vol 57 (4) ◽  
pp. 439-447 ◽  
Author(s):  
James A. Kleimeyer ◽  
Joel M. Harris
Keyword(s):  
Factor Analysis ◽  
Excited State ◽  
Ground State ◽  
Pure Component ◽  
Triplet States ◽  
Time Resolved ◽  
Pump Probe ◽  
Excited Triplet ◽  
Curve Resolution ◽  
Excited Triplet States

Resolution of transient excited-state Raman scattering from ground-state and solvent bands is a challenging spectroscopic measurement since excited-state spectral features are often of low intensity, overlapping the dominant ground-state and solvent bands. The Raman spectra of these intermediates can be resolved, however, by acquiring time-resolved data and using multidimensional data analysis methods. In the absence of a physical model describing the kinetic behavior of a reaction, resolution of the pure-component spectra from these data can be accomplished using self-modeling curve resolution, a factor analysis technique that relies on the correlation in the data along a changing composition dimension to resolve the component spectra. A two-laser UV pump-probe resonance-enhanced Raman instrument was utilized to monitor the kinetics of amine quenching of excited-triplet states of benzophenone. The formation and decay of transient intermediates were monitored over time, from 15 ns to 100 μs. Factor analysis of the time-resolved spectral data identified three significant components in the data. The time-resolved intensities at each Raman wavenumber shift were projected onto the three significant eigenvectors, and least-squares criteria were developed to find the common plane in the space of the eigenvectors that includes the observed data. Within that plane, the three pure-component spectra were resolved using geometric criteria of convex hull analysis. The resolved spectra were found to arise from benzophenone excited-triplet states, diphenylketyl radicals, and the solvent and ground-state benzophenone.

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

2021 ◽  
Author(s):  
Sarah E. Krul ◽  
Sean J. Hoehn ◽  
Karl Feierabend ◽  
Carlos Crespo-Hernández
Keyword(s):  
Excited State ◽  
Ground State ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Water Mixture ◽  
Relaxation Dynamics ◽  
Similar Time ◽  
Excited State Dynamics ◽  
Computational Calculations

<p>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 and in a mixture of methanol and water using femtosecond broadband transient absorption spectroscopy following excitation at 267 nm. The transient spectra are collected using photon densities that ensure no parasitic multiphoton-induced signal from solvated electrons. The data can be fit satisfactorily using a two- or three-component kinetic model. By analyzing the results from steady-state, time-resolved, computational calculations, and the methanol-water mixture, the following general relaxation mechanism is proposed for both molecules, L<sub>b</sub> ® L<sub>a</sub> ® <sup>1</sup>ps*(ICT) ® S<sub>0</sub>, where the <sup>1</sup>ps*(ICT) stands for an intramolecular charge transfer excited singlet state with significant ps* character. In general, longer lifetimes for internal conversion are obtained for 7-deazaguanosine compared to guanosine 5’-monophosphate. Internal conversion of the <sup>1</sup>ps*(ICT) state to the ground state occurs on a similar time scale of a few picoseconds in both molecules. 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 alter the topology of their potential energy surfaces in such a way that the relaxation dynamics in 7-deazaguanosine are slowed down compared to those in guanosine 5’-monophosphate but not for the internal conversion of <sup>1</sup>ps*(ICT) state to the ground state.</p>

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

2021 ◽  
Author(s):  
Sarah E. Krul ◽  
Sean J. Hoehn ◽  
Karl Feierabend ◽  
Carlos Crespo-Hernández
Keyword(s):  
Excited State ◽  
Ground State ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Water Mixture ◽  
Relaxation Dynamics ◽  
Similar Time ◽  
Excited State Dynamics ◽  
Computational Calculations

<p>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 and in a mixture of methanol and water using femtosecond broadband transient absorption spectroscopy following excitation at 267 nm. The transient spectra are collected using photon densities that ensure no parasitic multiphoton-induced signal from solvated electrons. The data can be fit satisfactorily using a two- or three-component kinetic model. By analyzing the results from steady-state, time-resolved, computational calculations, and the methanol-water mixture, the following general relaxation mechanism is proposed for both molecules, L<sub>b</sub> ® L<sub>a</sub> ® <sup>1</sup>ps*(ICT) ® S<sub>0</sub>, where the <sup>1</sup>ps*(ICT) stands for an intramolecular charge transfer excited singlet state with significant ps* character. In general, longer lifetimes for internal conversion are obtained for 7-deazaguanosine compared to guanosine 5’-monophosphate. Internal conversion of the <sup>1</sup>ps*(ICT) state to the ground state occurs on a similar time scale of a few picoseconds in both molecules. 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 alter the topology of their potential energy surfaces in such a way that the relaxation dynamics in 7-deazaguanosine are slowed down compared to those in guanosine 5’-monophosphate but not for the internal conversion of <sup>1</sup>ps*(ICT) state to the ground state.</p>

Ground-state recovery of coumarin dyes by pump-probe technique with picosecond pulses

Pramana ◽  
1992 ◽  
Vol 39 (4) ◽  
pp. 355-358 ◽  
Author(s):  
K Chandrasekhar ◽  
S R Inamdar ◽  
M N Dixit ◽  
N N Math
Keyword(s):  
Ground State ◽  
Pump Probe ◽  
Picosecond Pulses ◽  
Probe Technique ◽  
State Recovery ◽  
Coumarin Dyes
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