Addition of the Carbonyl Oxygen to theipso- orortho-Carbon Atoms of the β-Phenyl Ring Followed by Intersystem Crossing and Rapid Relaxation to the Ground-State Ketones: A Mechanism for β-Phenyl Quenching of the First Triplet Excited States of Derivatives of β-Phenylpropiophenone

2008 ◽  
Vol 112 (24) ◽  
pp. 5411-5417 ◽  
Author(s):  
Götz Bucher
Keyword(s):  
Excited States ◽  
Ground State ◽  
Phenyl Ring ◽  
Carbonyl Oxygen ◽  
Intersystem Crossing ◽  
Triplet Excited States ◽  
Derivatives Of

Energies and Dipole Moments of Excited States of Ozone and Ozone Radical Cation Using Fock Space Multireference Coupled-Cluster Analytical Response Approach

2003 ◽  
Vol 68 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Devarajan Ajitha ◽  
Kimihiko Hirao ◽  
Sourav Pal
Keyword(s):  
Excited States ◽  
Radical Cation ◽  
Ground State ◽  
Fock Space ◽  
Dipole Moments ◽  
Cation Radical ◽  
Coupled Cluster ◽  
Complete Active Space ◽  
Triplet Excited States ◽  
Ground State Geometry

Using the Fock space multireference coupled-cluster (FS-MRCC) analytical linear response approach, we report the dipole moments of low-lying singlet and triplet excited states of ozone. The low-lying singlet and triplet excited states are calculated at the ground-state geometry and at the adiabatic geometry for the 1A2 and 1B1. For comparison we also calculate at the ground-state geometry the dipole moments of the 1A2, 1B1 and 1B2 using multireference configuration interaction (MRCI) with a bigger VQZ basis and complete active space. We also report as by-product the excitation energy values in the singles and doubles approximation. At the ground-state geometry we also report the energy and the dipole moments of the 2A1, 2A2 and 2B1 states of the ozone radical cation. The energy of the ozone cation radical is compared with the other correlated approaches. It matches well with the experimental values.

scholarly journals Photochemical processes induced by the irradiation of 4-hydroxybenzophenone in different solvents

2015 ◽  
Vol 14 (11) ◽  
pp. 2087-2096 ◽  
Author(s):  
Francesco Barsotti ◽  
Marcello Brigante ◽  
Mohamed Sarakha ◽  
Valter Maurino ◽  
Claudio Minero ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Excited States ◽  
Ground State ◽  
Photochemical Processes ◽  
Triplet Excited States

The singlet and triplet excited states of 4-hydroxybenzophenone (4BPOH) undergo deprotonation in the presence of water to produce the anionic ground-state, causing fluorescence quenching and photoactivity inhibition.

Sorption of Substituted Phenylamides onto Bovine Serum Albumin

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 269-273 ◽  
Author(s):  
N. D. Camper ◽  
D. E. Moreland
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Phenyl Ring ◽  
Protein Modification ◽  
Carbonyl Oxygen ◽  
Amide Hydrogen ◽  
Amino Groups ◽  
Influence Of Ph ◽  
Derivatives Of

The influence of pH, temperature, ionic strength, and protein modification on the sorption (moles of chemical bound per mole of protein) of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) and 3′,4′-dichloropropionanilide (propanil) to bovine serum albumin (hereinafter referred to as BSA) was examined. Free amino groups of BSA were involved in the binding of both diuron and propanil. In addition, tryptophanyl residues appeared to be involved in the binding of propanil. Studies made with derivatives of diuron suggested that the amide hydrogen and carbonyl oxygen of the phenylamide are involved in the binding mechanism. Conformation of the protein was suggested to control the extent of binding. Increased chlorination of the phenyl ring was correlated with increased binding onto BSA. Propanil was bound to a greater extent than diuron by the protein.

scholarly journals Barrier-free reverse-intersystem crossing in organic molecules by strong light-matter coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Suman Mallick ◽  
Mao Wang ◽  
Karl Börjesson
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Strong Light ◽  
Light Emitting ◽  
Matter Coupling ◽  
Hund’S Rule ◽  
Electrically Pumped ◽  
Triplet Excited States ◽  
Hund's Rule

AbstractStrong light-matter coupling provides the means to challenge the traditional rules of chemistry. In particular, an energy inversion of singlet and triplet excited states would be fundamentally remarkable since it would violate the classical Hund’s rule. An organic chromophore possessing a lower singlet excited state can effectively harvest the dark triplet states, thus enabling 100% internal quantum efficiency in electrically pumped light-emitting diodes and lasers. Here we demonstrate unambiguously an inversion of singlet and triplet excited states of a prototype molecule by strong coupling to an optical cavity. The inversion not only implies that the polaritonic state lies at a lower energy, but also a direct energy pathway between the triplet and polaritonic states is opened. The intrinsic photophysics of reversed-intersystem crossing are thereby completely overturned from an endothermic process to an exothermic one. By doing so, we show that it is possible to break the limit of Hund’s rule and manipulate the energy flow in molecular systems by strong light-matter coupling. Our results will directly promote the development of organic light-emitting diodes based on reversed-intersystem crossing. Moreover, we anticipate that it provides the pathway to the creation of electrically pumped polaritonic lasers in organic systems.

scholarly journals Barrier-Free Reverse-Intersystem Crossing by Strong Light-Matter Coupling

2020 ◽  
Author(s):  
Yi YU ◽  
Suman Mallick ◽  
Mao Wang ◽  
Karl Börjesson
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Strong Light ◽  
Light Emitting ◽  
Matter Coupling ◽  
Hund’S Rule ◽  
Electrically Pumped ◽  
Triplet Excited States ◽  
Hund's Rule

Strong light-matter coupling provides the means to challenge the traditional rules of chemistry. In particular, an energy inversion of singlet and triplet excited states would be fundamentally remarkable since it would violate the classical Hund’s rule. An organic chromophore possessing a lower singlet excited state can effectively harvest the “dark” triplet states, thus enabling 100% internal quantum efficiency in electrically pumped light-emitting diodes and lasers. Here we demonstrate unambiguously an inversion of singlet and triplet excited states of a prototype molecule by strong coupling to an optical cavity. The inversion not only implies that the polaritonic state lies at a lower energy, but also a direct energy pathway between the triplet and polaritonic states is opened. The intrinsic photophysics of reversed-intersystem crossing are thereby completely overturned from an endothermic process to an exothermic one. By doing so, we show that it is possible to break the limit of Hund’s rule and manipulate the energy flow in molecular systems by strong light-matter coupling. Our results will directly promote the development of organic light-emitting diodes based on reversed-intersystem crossing. Moreover, we anticipate that it provides the pathway to the creation of electrically pumped polaritonic lasers in organic systems.

scholarly journals Structure-Reactivity Correlations of Excited States of Perfluorinated Compounds: A Time Resolved Raman Study

1999 ◽  
Vol 19 (1-4) ◽  
pp. 343-348 ◽  
Author(s):  
R. Anandhi ◽  
G. Balakrishnan ◽  
P. Mohandas ◽  
S. Umapathy
Keyword(s):  
Excited States ◽  
Ground State ◽  
Perfluorinated Compounds ◽  
Spectral Studies ◽  
Triplet Excited State ◽  
Time Resolved ◽  
Organic Systems ◽  
Structural Distortions ◽  
Raman Study ◽  
Triplet Excited States

This paper reports the TR3 spectral studies on perfluorinated organic systems with the objective to understand the influence of perfluorination on the excited states. We have recorded the TR3 spectra and Raman excitation profiles of the triplet excited states of decafluorobenzophenone and fluoranil. It is found that the influence of perfluorination is more pronounced in the triplet excited state than the ground state and thus leads to enhanced reactivity for perfluorinated compounds through larger structural distortions.

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