Ultrafast excited-state relaxation of a binuclear Ag(i) phosphine complex in gas phase and solution

2017 ◽  
Vol 19 (34) ◽  
pp. 22785-22800 ◽  
Author(s):  
S. V. Kruppa ◽  
F. Bäppler ◽  
W. Klopper ◽  
S. P. Walg ◽  
W. R. Thiel ◽  
...  
Keyword(s):  
Excited State ◽  
Gas Phase ◽  
Relaxation Dynamics ◽  
Phosphine Complex

The [Ag2(dcpm)2]2+ phosphine complex displays multiexponential excited-state relaxation dynamics both in the gas phase and in solution.

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.

scholarly journals Carrier dynamics and the role of surface defects: Designing a photocatalyst for gas-phase CO2 reduction

2016 ◽  
Vol 113 (50) ◽  
pp. E8011-E8020 ◽  
Author(s):  
Laura B. Hoch ◽  
Paul Szymanski ◽  
Kulbir Kaur Ghuman ◽  
Le He ◽  
Kristine Liao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Excited State ◽  
Oxygen Vacancy ◽  
Band Gap ◽  
Gas Phase ◽  
Density Functional ◽  
Carrier Dynamics ◽  
Valuable Insight ◽  
Relaxation Dynamics ◽  
Excitation Energies

In2O3-x(OH)y nanoparticles have been shown to function as an effective gas-phase photocatalyst for the reduction of CO2 to CO via the reverse water–gas shift reaction. Their photocatalytic activity is strongly correlated to the number of oxygen vacancy and hydroxide defects present in the system. To better understand how such defects interact with photogenerated electrons and holes in these materials, we have studied the relaxation dynamics of In2O3-x(OH)y nanoparticles with varying concentration of defects using two different excitation energies corresponding to above-band-gap (318-nm) and near-band-gap (405-nm) excitations. Our results demonstrate that defects play a significant role in the excited-state, charge relaxation pathways. Higher defect concentrations result in longer excited-state lifetimes, which are attributed to improved charge separation. This correlates well with the observed trends in the photocatalytic activity. These results are further supported by density-functional theory calculations, which confirm the positions of oxygen vacancy and hydroxide defect states within the optical band gap of indium oxide. This enhanced understanding of the role these defects play in determining the optoelectronic properties and charge carrier dynamics can provide valuable insight toward the rational development of more efficient photocatalytic materials for CO2 reduction.

Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

1996 ◽  
Vol 54 ◽  
pp. 154-155
Author(s):  
E. G. Rightor
Keyword(s):  
Excited State ◽  
Polymer Blends ◽  
Gas Phase ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Electronic States ◽  
Core Electron ◽  
Bulk Solids ◽  
Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

Simulation of UV Absorption Spectra and Relaxation Dynamics of Uracil and Uracil-Water Clusters

2020 ◽  
Author(s):  
Branislav Milovanović ◽  
Jurica Novak ◽  
Mihajlo Etinski ◽  
Wolfgang Domcke ◽  
Nadja Doslic
Keyword(s):  
Aqueous Solution ◽  
Gas Phase ◽  
Absorption Spectra ◽  
Absorption Spectroscopy ◽  
Water Clusters ◽  
Uv Absorption ◽  
Relaxation Dynamics ◽  
Nonradiative Relaxation ◽  
Uv Absorption Spectra ◽  
Uv Absorption Spectroscopy

Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy...

scholarly journals Ultrafast excited state dynamics and light-switching of [Ru(phen)2(dppz)]2+ in G-quadruplex DNA

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Chunfan Yang ◽  
Qian Zhou ◽  
Zeqing Jiao ◽  
Hongmei Zhao ◽  
Chun-Hua Huang ◽  
...  
Keyword(s):  
Excited State ◽  
State Formation ◽  
Rational Design ◽  
Bound Water ◽  
Binding Modes ◽  
Relaxation Dynamics ◽  
Dark State ◽  
Excited State Dynamics ◽  
G Quadruplex ◽  
Mechanistic Basis

AbstractThe triplet metal to ligand charge transfer (3MLCT) luminescence of ruthenium (II) polypyridyl complexes offers attractive imaging properties, specifically towards the development of sensitive and structure-specific DNA probes. However, rapidly-deactivating dark state formation may compete with 3MLCT luminescence depending on different DNA structures. In this work, by combining femtosecond and nanosecond pump-probe spectroscopy, the 3MLCT relaxation dynamics of [Ru(phen)2(dppz)]2+ (phen = 1,10-phenanthroline, dppz = dipyridophenazine) in two iconic G-quadruplexes has been scrutinized. The binding modes of stacking of dppz ligand on the terminal G-quartet fully and partially are clearly identified based on the biexponential decay dynamics of the 3MLCT luminescence at 620 nm. Interestingly, the inhibited dark state channel in ds-DNA is open in G-quadruplex, featuring an ultrafast picosecond depopulation process from 3MLCT to a dark state. The dark state formation rates are found to be sensitive to the content of water molecules in local G-quadruplex structures, indicating different patterns of bound water. The unique excited state dynamics of [Ru(phen)2(dppz)]2+ in G-quadruplex is deciphered, providing mechanistic basis for the rational design of photoactive ruthenium metal complexes in biological applications.

Excited state relaxation dynamics and up-conversion phenomena in Gd 3 (Al,Ga) 5 O 12 single crystals co-doped with holmium and ytterbium

2016 ◽  
Vol 656 ◽  
pp. 573-580 ◽  
Author(s):  
W. Ryba-Romanowski ◽  
J. Komar ◽  
T. Niedźwiedzki ◽  
M. Głowacki ◽  
M. Berkowski
Keyword(s):  
Excited State ◽  
Single Crystals ◽  
Relaxation Dynamics ◽  
Co Doped

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 Investigating the Environment-dependent Photophysics of Chlorine Dioxide With Resonance Raman Intensities

1999 ◽  
Vol 19 (1-4) ◽  
pp. 305-309
Author(s):  
Anthony P. Esposito ◽  
Catherine E. Foster ◽  
Philip J. Reid
Keyword(s):  
Excited State ◽  
Gas Phase ◽  
Chlorine Dioxide ◽  
Resonance Raman ◽  
Structural Evolution ◽  
Reaction Dynamics ◽  
Intensity Analysis ◽  
Normal Coordinates ◽  
Raman Intensities ◽  
Asymmetric Stretch

The condensed-phase excited-state reaction dynamics of chlorine dioxide are investigated using resonance Raman intensity analysis. Absolute Raman intensities are measured on resonance with the 2B2–2A2 electronic transition and used to establish the excited-state structural evolution which occurs on the 2A2 surface following photoexcitation. Analysis of the intensities demonstrates that excited-state relaxation occurs along all three normal coordinates; however, only modest evolution is observed along the asymmetric stretch. This limited relaxation stands in contrast to the extensive motion along this coordinate in the gas phase. It is proposed that the initial excited-state structural relaxation serves to define the symmetry of the reaction coordinate and thus the mechanism of Cl production following photolysis of OClO.

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