Impact of Vibrational Coherence on the Quantum Yield at a Conical Intersection

2016 ◽  
Vol 7 (17) ◽  
pp. 3491-3496 ◽  
Author(s):  
Hong-Guang Duan ◽  
R. J. Dwayne Miller ◽  
Michael Thorwart
Keyword(s):  
Quantum Yield ◽  
Conical Intersection ◽  
Vibrational Coherence

scholarly journals Internal conversion of the anionic GFP chromophore: in and out of the I-twisted S1/S0 conical intersection seam

2022 ◽  
Author(s):  
Nanna H. List ◽  
Chey M. Jones ◽  
Todd J. Martínez
Keyword(s):  
Quantum Yield ◽  
Internal Conversion ◽  
Conical Intersection ◽  
Statistical Dynamics ◽  
Statistical Behavior ◽  
Gfp Chromophore

The Z–E photoisomerization quantum yield of the HBDI− chromophore is a result of early, non-statistical dynamics around a less reactive I-twisted intersection and later, statistical behavior around the more reactive, near-enantiomeric counterpart.

scholarly journals Constraint Trajectory Surface-Hopping Molecular Dynamics Simulation of the Photoisomerization of Stilbene

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Yibo Lei ◽  
Shaomei Wu ◽  
Chaoyuan Zhu ◽  
Zhenyi Wen ◽  
Sheng-Hsien Lin
Keyword(s):  
Molecular Dynamics ◽  
Quantum Yield ◽  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Branching Ratio ◽  
Dynamics Simulation ◽  
Conical Intersection ◽  
Surface Hopping ◽  
Internal Coordinates ◽  
Energy Surfaces

Combining trajectory surface hopping (TSH) method with constraint molecular dynamics, we have extended TSH method from full to flexible dimensional potential energy surfaces. Classical trajectories are carried out in Cartesian coordinates with constraints in internal coordinates, while nonadiabatic switching probabilities are calculated separately in free internal coordinates by Landau-Zener and Zhu-Nakamura formulas along the seam. Two-dimensional potential energy surfaces of groundS0and excitedS1states are constructed analytically in terms of torsion angle and one dihedral angle around the central ethylenic C=C bond, and the other internal coordinates are all fixed at configuration of the conical intersection. At this conical intersection, the branching ratio from the present simulation is 48 : 52 (33 : 67) initially starting from trans(cis)-Stilbene in comparison with experimental value 50 : 50. Quantum yield for trans-to-cis isomerization is estimated as 49% in very good agreement with experimental value of 55%, while quantum yield for cis-to-trans isomerization is estimated as 47% in comparison with experimental value of 35%.

scholarly journals The Photoisomerization Pathway(s) of Push-Pull Phenylazoheteroarenes

2020 ◽  
Author(s):  
Sergi Vela ◽  
Clemence Corminboeuf
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Quantum Yield ◽  
Working Conditions ◽  
Azo Dyes ◽  
Conical Intersection ◽  
Substitution Effects ◽  
Isomerization Pathway ◽  
And Inversion

<div> <p>Azoheteroarenes are the most recent derivatives targeted to further improve the properties of azo-based photoswitches. Their light-induced mechanism for trans-cis isomerization is assumed to be very similar to that of the parent azobenzene. As such, they inherited from the controversy about the dominant isomerization pathway (rotation<i> vs.</i> inversion) depending on the excited state (nπ* <i>vs.</i> ππ*). While the controversy seems settled in azobenzene, the extent to which the same conclusions apply to the more structurally-diverse family of azoheteroarenes is unclear. Here, we unravel by means of non-adiabatic molecular dynamics, the photoisomerization mechanism of three prototypical phenyl-azoheteroarenes with an increasing push-pull<i> </i>character. The evolution of the rotational and inversion conical intersection energies, the preferred pathway, and the associated kinetics upon both nπ* and ππ* excitations can be linked directly with the push-pull substitution effects. Overall, we clarify the working conditions of this family of azo-dyes and identify a possibility to exploit push-pull substituents to tune their photoisomerization quantum yield.</p> </div> <br>

scholarly journals Solvent-dependent dual fluorescence of the push–pull system 2-diethylamino-7-nitrofluorene

2018 ◽  
Vol 20 (8) ◽  
pp. 5942-5951 ◽  
Author(s):  
M. A. B. Larsen ◽  
A. B. Stephansen ◽  
E. Alarousu ◽  
M. Pittelkow ◽  
O. F. Mohammed ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Conical Intersection ◽  
Dual Fluorescence ◽  
Pull System ◽  
System 2

We characterize the conical intersection determining the fluorescence quantum yield and demonstrate the competition between ISC and dual fluorescence.

scholarly journals Vibrational coherence and quantum yield of retinal-chromophore-inspired molecular switches

2020 ◽  
Vol 221 ◽  
pp. 299-321 ◽  
Author(s):  
Moussa Gueye ◽  
Marco Paolino ◽  
Etienne Gindensperger ◽  
Stefan Haacke ◽  
Massimo Olivucci ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Transient Absorption ◽  
Molecular Switches ◽  
Systematic Investigation ◽  
Vibrational Coherence ◽  
Retinal Chromophore ◽  
Molecular Framework

UV-Vis transient absorption (TA) spectroscopy is used to carry out a systematic investigation of the ultrafast CC double photoisomerization dynamics and quantum yield of each isomer of a set of six chromophores based on the same retinal-inspired, indanylidene pyrrolinium (IP) molecular framework.

Trajectory surface hopping molecular dynamics simulations for retinal protonated Schiff-base photoisomerization

2021 ◽  
Author(s):  
Yuxiu Liu ◽  
Chaoyuan Zhu
Keyword(s):  
Molecular Dynamics ◽  
Schiff Base ◽  
Quantum Yield ◽  
Potential Energy ◽  
Molecular Dynamics Simulations ◽  
Potential Energy Surfaces ◽  
Conical Intersection ◽  
Surface Hopping ◽  
Dynamics Simulations ◽  
Energy Surfaces

A global-switching trajectory surface hopping method on TDDFT potential energy surfaces has been used to simulate complex conical intersection networks and to predict photoproduct quantum yield distributions for a real RPSB system.

scholarly journals The Photoisomerization Pathway(s) of Push-Pull Phenylazoheteroarenes

2020 ◽  
Author(s):  
Sergi Vela ◽  
Clemence Corminboeuf
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Quantum Yield ◽  
Working Conditions ◽  
Azo Dyes ◽  
Conical Intersection ◽  
Substitution Effects ◽  
Isomerization Pathway ◽  
And Inversion

<div> <p>Azoheteroarenes are the most recent derivatives targeted to further improve the properties of azo-based photoswitches. Their light-induced mechanism for trans-cis isomerization is assumed to be very similar to that of the parent azobenzene. As such, they inherited from the controversy about the dominant isomerization pathway (rotation<i> vs.</i> inversion) depending on the excited state (nπ* <i>vs.</i> ππ*). While the controversy seems settled in azobenzene, the extent to which the same conclusions apply to the more structurally-diverse family of azoheteroarenes is unclear. Here, we unravel by means of non-adiabatic molecular dynamics, the photoisomerization mechanism of three prototypical phenyl-azoheteroarenes with an increasing push-pull<i> </i>character. The evolution of the rotational and inversion conical intersection energies, the preferred pathway, and the associated kinetics upon both nπ* and ππ* excitations can be linked directly with the push-pull substitution effects. Overall, we clarify the working conditions of this family of azo-dyes and identify a possibility to exploit push-pull substituents to tune their photoisomerization quantum yield.</p> </div> <br>

Size-dependent emission of a dipole coupled to a metal nanoparticle

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3315-3325
Author(s):  
Viktoriia Savchuk ◽  
Arthur R. Knize ◽  
Pavlo Pinchuk ◽  
Anatoliy O. Pinchuk
Keyword(s):  
Numerical Analysis ◽  
Quantum Yield ◽  
Electric Dipole ◽  
Incident Radiation ◽  
Metal Nanoparticle ◽  
Plasmonic Nanoparticle ◽  
Size Dependent ◽  
Emission Enhancement ◽  
Electric Dipoles

AbstractWe present a systematic numerical analysis of the quantum yield of an electric dipole coupled to a plasmonic nanoparticle. We observe that the yield is highly dependent on the distance between the electric dipole and the nanoparticle, the size and permittivity of the nanoparticle, and the wavelength of the incident radiation. Our results indicate that enhancement of the quantum yield is only possible for electric dipoles coupled to a nanoparticle with a radius of 20 nm or larger. As the size of the nanoparticle is increased, emission enhancement occurs at wavelengths dependent on the coupling distance.

Highly Fluorescent Au25-xAgx Nanoclusters Protected with Poly(ethylene glycol) - and Zwitterion-Modified Thiolate Ligands

2018 ◽  
Author(s):  
Dinesh Mishra ◽  
Sisi Wang ◽  
Zhicheng Jin ◽  
Eric Lochner ◽  
Hedi Mattoussi
Keyword(s):  
Quantum Yield ◽  
Near Infrared ◽  
Small Diameter ◽  
Binding Energies ◽  
Thiolate Ligands ◽  
Nir Emission ◽  
Thiolate Complexes ◽  
Long Lifetime ◽  
Poly Ethylene

<p>We describe the growth and characterization of highly fluorescing, near-infrared-emitting nanoclusters made of bimetallic Au<sub>25-x</sub>Ag<sub>x</sub> cores, prepared using various monothiol-appended hydrophobic and hydrophilic ligands. The reaction uses well-defined triphenylphosphine-protected Au<sub>11</sub> clusters (as precursors), which are reacted with Ag(I)-thiolate complexes. The prepared nanoclusters are small (diameter < 2nm, as characterized by TEM) with emission peak at 760 nm and long lifetime (~12 µs). The quantum yield measured for these materials was 0.3 - 0.4 depending on the ligand. XPS measurements show the presence of both metal atoms in the core, with measured binding energies that agree with reported values for nanocluster materials. The NIR emission combined with high quantum yield, small size and ease of surface functionalization afforded by the coating, make these materials suitable to implement investigations that address fundamental questions and potentially useful for biological sensing and imaging applications.<br></p>

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