scholarly journals Altered relaxation dynamics of excited state reactions by confinement in reverse micelles probed by ultrafast fluorescence up-conversion

2021 ◽  
Author(s):  
Ismael A. Heisler ◽  
Stephen R. Meech
Keyword(s):  
Excited State ◽  
Real Time ◽  
Reverse Micelles ◽  
Reaction Dynamics ◽  
Time Study ◽  
Relaxation Dynamics ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Time resolved fluorescence follows reaction dynamics in real-time. Study of reaction which are sensitive to their environment allowed the effect of confinement to be observed and studied.

Excited-state dynamics of guanosine in aqueous solution revealed by time-resolved photoelectron spectroscopy: experiment and theory

2015 ◽  
Vol 17 (47) ◽  
pp. 31978-31987 ◽  
Author(s):  
Franziska Buchner ◽  
Berit Heggen ◽  
Hans-Hermann Ritze ◽  
Walter Thiel ◽  
Andrea Lübcke
Keyword(s):  
Aqueous Solution ◽  
Excited State ◽  
Photoelectron Spectroscopy ◽  
Relaxation Dynamics ◽  
Time Resolved ◽  
Excited State Dynamics ◽  
Spectroscopy Experiment

Time-resolved photoelectron spectroscopy is performed on aqueous guanosine solution to study its excited-state relaxation dynamics.

scholarly journals Фотофизические процессы в молекулах галогенпроизводных флуоресцеина в анионных обратных мицеллах

2020 ◽  
Vol 128 (12) ◽  
pp. 1842
Author(s):  
О.И. Волкова ◽  
А.А. Кулешова ◽  
Б.Н. Корватовский ◽  
А.М. Салецкий
Keyword(s):  
Reverse Micelles ◽  
Heavy Atom ◽  
Rotational Correlation Time ◽  
Dye Molecules ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Micellar Systems ◽  
Aqueous Micellar Solutions ◽  
Derivatives Of ◽  
Rotational Correlation

Studies of photophysical processes in aqueous micellar solutions of halogen derivatives of fluorescein: Eosin( E), Erythrosin (ER) and Bengal Rose (BR) by methods of dynamic light scattering, stationary and time-resolved fluorescence spectroscopy were carried out. It was found that the introduction of dye molecules into reverse AOT micelles causes an increase in their hydrodynamic radii Rh. The time-resolved fluorescence of the studied dye molecules in reverse micelles was measured. A decrease in the average time of the excited state with an increase in Rh for E, ER, and BR was found, which is associated with an increase in the mobility of water molecules and a decrease in the effect of geometric restriction of dye molecules. The degrees of anisotropy of the fluorescence r of dye molecules in reverse micelles were measured. It was shown that in micellar systems r is greater than in aqueous solutions and decreases with increasing Rh. The rotational correlation time for the studied dye molecules in micellar systems is determined, which decreases for all the studied dyes with an increase in Rh, indicating a decrease in the microviscosity of the confined aqueous medium inside the micelle. In this case , i.e., the value of the time of the rotational correlation is affected by the "heavy atom effect".

Excited-state relaxation dynamics of Re(I) tricarbonyl complexes with macrocyclic phenanthroline ligands studied by time-resolved IR spectroscopy

2009 ◽  
pp. 3941 ◽  
Author(s):  
Ana María Blanco-Rodríguez ◽  
Michael Towrie ◽  
Jean-Paul Collin ◽  
Stanislav Záliš ◽  
Antonín Vlček Jr.
Keyword(s):  
Excited State ◽  
Ir Spectroscopy ◽  
Relaxation Dynamics ◽  
Time Resolved ◽  
Phenanthroline Ligands

scholarly journals Probing relaxation dynamics of a cationic lipid based non-viral carrier: a time-resolved fluorescence study

RSC Advances ◽  
2019 ◽  
Vol 9 (61) ◽  
pp. 35549-35558 ◽  
Author(s):  
Priya Singh ◽  
Dipanjan Mukherjee ◽  
Subhankar Singha ◽  
V. K. Sharma ◽  
Ismail I. Althagafi ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Cationic Lipid ◽  
Lipid Vesicles ◽  
Relaxation Dynamics ◽  
Time Resolved Fluorescence ◽  
Fluorescence Study ◽  
Time Resolved ◽  
Dioctadecyldimethylammonium Bromide

Lipid vesicles composed of cationic dioctadecyldimethylammonium bromide (DODAB) and neutral 1-monooleoyl-rac-glycerol (MO) are promising non-viral carriers of nucleic acids for delivery into cells.

Observation of multi-channel non-adiabatic dynamics in aniline derivatives using time-resolved photoelectron imaging

2016 ◽  
Vol 194 ◽  
pp. 185-208 ◽  
Author(s):  
Magdalena M. Zawadzki ◽  
Marco Candelaresi ◽  
Lisa Saalbach ◽  
Stuart W. Crane ◽  
Martin J. Paterson ◽  
...  
Keyword(s):  
Excited State ◽  
Angular Distributions ◽  
Relaxation Dynamics ◽  
Photoelectron Imaging ◽  
Time Resolved ◽  
Valence States ◽  
Ultimate Fate ◽  
Site Selective ◽  
Photoelectron Angular Distributions ◽  
Electronic Character

We present results from a recent time-resolved photoelectron imaging (TRPEI) study investigating the non-adiabatic relaxation dynamics of N,N-dimethylaniline (N,N-DMA) and 3,5-dimethylaniline (3,5-DMA) following excitation at 240 nm. Analysis of the experimental data is supported by ab initio coupled-cluster calculations evaluating excited state energies and the evolution of several excited state physical properties as a function of N–H/N–CH3 bond extension – a critical reaction coordinate. The use of site-selective methylation brings considerable new insight to the existing body of literature concerning photochemical dynamics in the related system aniline at similar excitation wavelengths. The present work also builds on our own previous investigations in the same species at 250 nm. The TRPEI method provides highly differential energy- and angle-resolved data and, in particular, the temporal evolution of the photoelectron angular distributions afforded by the imaging approach offers much of the new dynamical information. In particular, we see no clear evidence of the second excited 2ππ* state non-adiabatically coupling to the lower-lying S1(ππ*) state or the mixed Rydberg/valence S2(3s/πσ*) state. This, in turn, potentially raises some unresolved questions about the overall nature of the dynamics operating in these systems, especially in regard to the 2ππ* state's ultimate fate. More generally, the findings for the aromatic systems N,N-DMA and 3,5-DMA, taken along with our recent TRPEI results for several aliphatic amine species, highlight interesting questions about the nature of electronic character evolution in mixed Rydberg-valence states as a function of certain key bond extensions and the extent of system conjugation. We begin exploring these ideas computationally for a systematically varied series of tertiary amines.

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