scholarly journals On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion

2015 ◽  
Vol 6 (2) ◽  
pp. 1578-1589 ◽  
Author(s):  
James N. Bull ◽  
Christopher W. West ◽  
Jan R. R. Verlet
Keyword(s):  
Gas Phase ◽  
Electronic State ◽  
Vitamin K ◽  
Radical Anion ◽  
Ground Electronic State ◽  
Radical Anions ◽  
Photoelectron Imaging ◽  
Time Resolved

Frequency-, angle-, and time-resolved photoelectron imaging of gas-phase menadione (vitamin K3) radical anions is used to show that quasi-bound resonances of the anion can act as efficient doorway states to produce metastable ground electronic state anions on a sub-picosecond timescale.

scholarly journals A deep UV trigger for ground-state ring-opening dynamics of 1,3-cyclohexadiene

2019 ◽  
Vol 5 (9) ◽  
pp. eaax6625 ◽  
Author(s):  
Jennifer M. Ruddock ◽  
Haiwang Yong ◽  
Brian Stankus ◽  
Wenpeng Du ◽  
Nathan Goff ◽  
...  
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Ground Electronic State ◽  
Source Analysis ◽  
Time Resolved ◽  
X Ray Scattering ◽  
Linac Coherent Light Source ◽  
Scattering Anisotropy ◽  
Kinetics Of ◽  
Single Bonds

We explore the photo-induced kinetics of 1,3-cyclohexadiene upon excitation at 200 nm to the 3p state by ultrafast time-resolved, gas-phase x-ray scattering using the Linac Coherent Light Source. Analysis of the scattering anisotropy reveals that the excitation leads to the 3px and 3py Rydberg electronic states, which relax to the ground state with a time constant of 208 ± 11 fs. In contrast to the well-studied 266 nm excitation, at 200 nm the majority of the molecules (76 ± 3%) relax to vibrationally hot cyclohexadiene in the ground electronic state. A subsequent reaction on the ground electronic state surface leads from the hot cyclohexadiene to 1,3,5-hexatriene, with rates for the forward and backward reactions of 174 ± 13 and 355 ± 45 ps, respectively. The scattering pattern of the final hexatriene product reveals a thermal distribution of rotamers about the carbon-carbon single bonds.

scholarly journals Ultrafast photoisomerisation of an isolated retinoid

2019 ◽  
Vol 21 (20) ◽  
pp. 10567-10579 ◽  
Author(s):  
James N. Bull ◽  
Christopher W. West ◽  
Cate S. Anstöter ◽  
Gabriel da Silva ◽  
Evan J. Bieske ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Excited State ◽  
Gas Phase ◽  
Laser Spectroscopy ◽  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Photoelectron Imaging ◽  
Time Resolved ◽  
Excited State Dynamics

The photoinduced excited state dynamics of gas-phase trans-retinoate (deprotonated trans-retinoic acid, trans-RA−) are studied using tandem ion mobility spectrometry coupled with laser spectroscopy, and frequency-, angle- and time-resolved photoelectron imaging.

Generation of ground electronic state haloalkyl radicals in the gas phase

1986 ◽  
Vol 18 (6) ◽  
pp. 639-649 ◽  
Author(s):  
B. E. Holmes ◽  
S. D. Paisley ◽  
D. J. Rakestraw ◽  
E. E. King
Keyword(s):  
Gas Phase ◽  
Electronic State ◽  
Ground Electronic State

An electron spin resonance and time-resolved CIDEP study of the oxidation of ascorbic acid by pyruvic acid, duroquinone, and vitamin K1

1981 ◽  
Vol 59 (18) ◽  
pp. 2708-2713 ◽  
Author(s):  
M. Catherine Depew ◽  
Babatunde B. Adeleke ◽  
Jeffrey K. S. Wan
Keyword(s):  
Electron Transfer ◽  
Vitamin C ◽  
Vitamin K ◽  
Pyruvic Acid ◽  
Radical Anion ◽  
Relative Difference ◽  
Transfer Mechanism ◽  
Model Systems ◽  
Time Resolved ◽  
Electron Transfer Mechanism

The photooxidation of vitamin C by pyruvic acid and its derivatives, duroquinone, and vitamin K1, is systematically studied by the combined esr and time-resolved CIDEP technique. Because of the unique property of the triplet pyruvic acid which is different from that of the duroquinone triplet, the choice of these model systems allowed the CIDEP observations of the initial polarization of the ascorbate radical anion and its counter primary radical in either the enhanced absorptive or the emissive mode. The results demonstrate the efficient photooxidation of vitamin C by the triplet vitamin K1 and that the latter triplet possesses similar properties as the triplet quinones. In the photooxidation system involving vitamin C and pyruvic acid, the adjustment of the pH of the aqueous solution afforded an opportunity to observe the photochemical reaction between two anions, the pyruvate anion and the ascorbate anion. Arguments were made in favor of an electron transfer mechanism for the oxidation of vitamin C by triplet vitamin K1 but against the electron transfer mechanism for the oxidation of vitamin C by triplet pyruvate anion. T1 values of the primary radicals estimated from their CIDEP transient responses at low microwave power are reported and it was suggested that the hydrogen-bonding capacity of the ascorbate radical anion in water does not contribute significantly to the relative difference of T1's between itself and the counter pyruvic ketyl radical.

Time-resolved photoionization spectroscopy of mixed Rydberg-valence states: indole case study

2015 ◽  
Vol 17 (40) ◽  
pp. 26659-26669 ◽  
Author(s):  
Magdalena M. Zawadzki ◽  
James O. F. Thompson ◽  
Emma A. Burgess ◽  
Martin J. Paterson ◽  
Dave Townsend
Keyword(s):  
Gas Phase ◽  
Relaxation Dynamics ◽  
Photoelectron Imaging ◽  
Time Resolved ◽  
Mechanistic Insight ◽  
Valence States ◽  
Insight Into

Time-resolved photoelectron imaging reveals subtle new mechanistic insight into the ultraviolet relaxation dynamics of gas-phase indole.

Sign in / Sign up

Export Citation Format

Share Document