scholarly journals Ultrafast internal conversion dynamics of highly excited pyrrole studied with VUV/UV pump probe spectroscopy

2017 ◽  
Vol 146 (6) ◽  
pp. 064306 ◽  
Author(s):  
Spencer L. Horton ◽  
Yusong Liu ◽  
Pratip Chakraborty ◽  
Spiridoula Matsika ◽  
Thomas Weinacht
Keyword(s):  
Internal Conversion ◽  
Pump Probe ◽  
Probe Spectroscopy

scholarly journals Excited-state dynamics of overlapped optically-allowed 1B(u)+ and optically-forbidden 1B(u)- or 3A(g)- vibronic levels of carotenoids: possible roles in the light-harvesting function.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Yasushi Koyama ◽  
Yoshinori Kakitani ◽  
Hiroyoshi Nagae
Keyword(s):  
Internal Conversion ◽  
Selection Rule ◽  
Polar Solvent ◽  
Selective Excitation ◽  
Stimulated Emission ◽  
Quantum Beat ◽  
Pump Probe ◽  
Cross Term ◽  
Hand Pump ◽  
Probe Spectroscopy

Pump-probe spectroscopy after selective excitation of all-trans Cars (n = 9-13) in nonpolar solvent identified a symmetry selection rule of diabatic electronic mixing and diabatic internal conversion, i.e., '1B(u)(+)-to-1B(u)(-) is allowed but 1B(u)(+)-to-3A(g)(-) is forbidden'. Kerr-gate fluorescence spectroscopy showed that this selection rule breaks down, due to the symmetry degradation when the Car molecules are being excited, and, as a result, the 1B(u)(+)-to-3A(g)(-) diabatic electronic mixing and internal conversion become allowed. On the other hand, pump-probe spectroscopy after coherent excitation of the same set of Cars in polar solvent identified three stimulated-emission components (generated by the quantum-beat mechanism), consisting of the long-lived coherent cross term from the 1B(u)(+) + 1B(u)(-) or 1B(u)(+) + 3A(g)(-) diabatic pair and incoherent short-lived 1B(u)(+) and 1B(u)(-) or 3A(g)(-) split incoherent terms. The same type of stimulated-emission components were identified in Cars bound to LH2 complexes, their lifetimes being substantially shortened by the Car-to-BChl singlet-energy transfer. Each diabatic pair and its split components appeared with high intensities in the first component. The low-energy shifts of the 1B(u)(+)(0), 1B(u)(-)(0) and 3A(g)(-)(0) levels and efficient triplet generation were also found.

Broadband pump-probe spectroscopy with sub-10-fs resolution for probing ultrafast internal conversion and coherent phonons in carotenoids

2008 ◽  
Vol 350 (1-3) ◽  
pp. 45-55 ◽  
Author(s):  
D. Polli ◽  
M.R. Antognazza ◽  
D. Brida ◽  
G. Lanzani ◽  
G. Cerullo ◽  
...  
Keyword(s):  
Internal Conversion ◽  
Pump Probe ◽  
Coherent Phonons ◽  
Probe Spectroscopy

Subpicosecond vibrational relaxation of the S1 states of azulene and guaiazulene in solution

1995 ◽  
Vol 73 (2) ◽  
pp. 303-306 ◽  
Author(s):  
Dietrich Tittelbach-Helmrich ◽  
Brian D. Wagner ◽  
Ronald P. Steer
Keyword(s):  
Vibrational Relaxation ◽  
Internal Conversion ◽  
Vibrational Energy ◽  
Energy Content ◽  
Pump Probe ◽  
Decay Times ◽  
Probe Experiment ◽  
Pump Probe Experiment ◽  
Probe Spectroscopy ◽  
Electronic Ground

The S1 population decay times of azulene and 1,4-dimethyl-7-isopropylazulene (guaiazulene) in solution have been determined as a function of their initial vibrational energy content, [Formula: see text] using a pump–probe experiment with subpicosecond time resolution. The S1 lifetime of azulene does not depend on [Formula: see text] for energies up to 1760 cm−1, whereas the lifetime of the shorter-lived S1 state of guaiazulene is independent of [Formula: see text] only for energies up to ~1000 cm−1. At higher energies, the lifetime decreases with increasing [Formula: see text] and exhibits the same behavior in two structurally different solvents. It is suggested that internal conversion to the electronic ground state from a vibrationally unrelaxed S1 state is responsible for the effects observed in guaiazulene, and that intramolecular vibrational redistribution occurs with a time constant of several hundred femtoseconds. Keywords: pump–probe spectroscopy, azulene, femtosecond processes.

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

Classical theory of ultrafast pump-probe spectroscopy: Applications to I2 photodissociation in Ar solution

1994 ◽  
Vol 61 (1-3) ◽  
pp. 153-165 ◽  
Author(s):  
Robert M. Whitnell ◽  
Kent R. Wilson ◽  
YiJing Yan ◽  
Ahmed H. Zewail
Keyword(s):  
Classical Theory ◽  
Pump Probe ◽  
Probe Spectroscopy

Coherent pump–probe spectroscopy of a Λ system with a close lying excited level

2013 ◽  
Vol 88 (6) ◽  
pp. 065404 ◽  
Author(s):  
Niharika Singh ◽  
Ayan Ray ◽  
R D'Souza ◽  
Q V Lawande ◽  
B N Jagatap
Keyword(s):  
Excited Level ◽  
Pump Probe ◽  
Probe Spectroscopy

Ultrafast pump-probe spectroscopy of native etiolated oat phytochrome

Biochemistry ◽  
1993 ◽  
Vol 32 (29) ◽  
pp. 7512-7518 ◽  
Author(s):  
Sergei Savikhin ◽  
Todd Wells ◽  
Pill Soon Song ◽  
Walter S. Struve
Keyword(s):  
Pump Probe ◽  
Probe Spectroscopy

Ultrafast pump-probe spectroscopy: femtosecond dynamics in Liouville space

1989 ◽  
Vol 93 (25) ◽  
pp. 8149-8162 ◽  
Author(s):  
Yi Jing Yan ◽  
Laurence E. Fried ◽  
Shaul Mukamel
Keyword(s):  
Pump Probe ◽  
Liouville Space ◽  
Femtosecond Dynamics ◽  
Probe Spectroscopy
Sign in / Sign up

Export Citation Format

Share Document