Excited states of S+14 ion (1S nS) in singlet and triplet states (1S, 3S) by Hartree-Fock method

2021 ◽  
Vol 15 (1) ◽  
pp. 92
Author(s):  
Ban Hussein Alruwaishidi ◽  
Rukia Jabar Dosh ◽  
Ali Abid Abojassim
Keyword(s):  
Excited States ◽  
Triplet States ◽  
Hartree Fock ◽  
Singlet And Triplet States

scholarly journals Exploiting trifluoromethyl substituents for tuning orbital character of singlet and triplet states to increase the rate of thermally activated delayed fluorescence

2020 ◽  
Vol 4 (12) ◽  
pp. 3602-3615 ◽  
Author(s):  
Jonathan S. Ward ◽  
Andrew Danos ◽  
Patrycja Stachelek ◽  
Mark A. Fox ◽  
Andrei S. Batsanov ◽  
...  
Keyword(s):  
Excited States ◽  
Organic Molecules ◽  
Delayed Fluorescence ◽  
Triplet States ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Conjugated Organic Molecules ◽  
Singlet And Triplet States ◽  
Triplet Excited States ◽  
Orbital Character

This work shows that trifluoromethyl (CF3) substituents can be used to increase the rate of thermally activated delayed fluorescence (TADF) in conjugated organic molecules by tuning the excitonic character of the singlet and triplet excited states.

scholarly journals Photophysical Properties of Nitrated and Halogenated Phosphorus Tritolylcorrole Complexes: Insights from Theory

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2779 ◽  
Author(s):  
Marta Alberto ◽  
Bruna De Simone ◽  
Gloria Mazzone ◽  
Nino Russo ◽  
Marirosa Toscano
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Energy Gap ◽  
Photophysical Properties ◽  
Intersystem Crossing ◽  
Triplet States ◽  
Excited Singlet ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Singlet And Triplet States

The photophysical properties of a series of nitrated and halogenated phosphorus tritolylcorrole complexes were studied in dichloromethane solvent by using the density functional theory. Particular emphasis was given to the absorption spectra, the energy gap between the excited singlet and triplet states, and the magnitude of the spin-orbit couplings for a series of possible intersystem crossing channels between those excited states. The proposed study provides a better description of the photophysical properties of these systems while giving insights into their possible use as photosensitizers in photodynamic therapy.

Vibrationally-resolved spectroscopic studies of electronically excited states of 1,8-naphthalic anhydride and 1,8-naphthalimide: a delicate interplay between one ππ* and two nπ* states

2017 ◽  
Vol 19 (8) ◽  
pp. 5861-5869 ◽  
Author(s):  
Elena Maltseva ◽  
Saeed Amirjalayer ◽  
Wybren Jan Buma
Keyword(s):  
Excited States ◽  
Spectroscopic Studies ◽  
Triplet States ◽  
Electronically Excited States ◽  
Naphthalic Anhydride ◽  
Electronically Excited ◽  
Singlet And Triplet States

Vibrationally-resolved spectroscopy disentangles coupled vibronic manifolds of lower electronic singlet and triplet states of naphthalene-based heterocyclic chromophores.

scholarly journals Are Multicentre Bond Indices and Related Quantities Reliable Predictors of Excited-State Aromaticity?

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4791
Author(s):  
Robert Ponec ◽  
David L. Cooper ◽  
Peter B. Karadakov
Keyword(s):  
Excited State ◽  
Excited States ◽  
Similarity Index ◽  
Triplet States ◽  
Complete Active Space ◽  
First Order ◽  
Consistent Field ◽  
Self Consistent Field ◽  
Singlet And Triplet States ◽  
Bond Indices

Systematic scrutiny is carried out of the ability of multicentre bond indices and the NOEL-based similarity index dAB to serve as excited-state aromaticity criteria. These indices were calculated using state-optimized complete active-space self-consistent field wavefunctions for several low-lying singlet and triplet states of the paradigmatic molecules of benzene and square cyclobutadiene and the inorganic ring S2N2. The comparison of the excited-state indices with aromaticity trends for individual excited states suggested by the values of magnetic aromaticity criteria show that whereas the indices work well for aromaticity reversals between the ground singlet and first triplet electronic states, addressed by Baird’s rule, there are no straightforward parallels between the two sets of data for singlet excited states. The problems experienced while applying multicentre bond indices and dAB to singlet excited states are explained by the loss of the information inherently present in wavefunctions and/or pair densities when calculating the first-order density matrix.

Parsorbitalm ethode, 6. Mitt. : 1Charakterordnungen angeregter Zustände 2/ Character Orders of Excited States

1974 ◽  
Vol 29 (3) ◽  
pp. 529-530
Author(s):  
Oskar E. Polansky
Keyword(s):  
Excited States ◽  
Triplet States ◽  
Reaction Paths ◽  
Excited Singlet ◽  
Complete Neglect ◽  
Singlet And Triplet States

In spite of the complete neglect of spins in HMO theory different character orders are obtained for the lowest excited singlet and triplet states. Since 3φʟ* > 1φʟ*, possibly the typical reaction paths of tripletts are mainly determined by electronic factors

scholarly journals How do the Hückel and Baird Rules Fade away in Annulenes?

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 711 ◽  
Author(s):  
Irene Casademont-Reig ◽  
Eloy Ramos-Cordoba ◽  
Miquel Torrent-Sucarrat ◽  
Eduard Matito
Keyword(s):  
Density Functional ◽  
Geometry Optimization ◽  
Ring Structure ◽  
Orbital Method ◽  
Triplet States ◽  
Molecular Orbital Method ◽  
Geometrical Structures ◽  
Hartree Fock ◽  
Aromatic Character ◽  
Singlet And Triplet States

Two of the most popular rules to characterize the aromaticity of molecules are those due to Hückel and Baird, which govern the aromaticity of singlet and triplet states. In this work, we study how these rules fade away as the ring structure increases and an optimal overlap between p orbitals is no longer possible due to geometrical restrictions. To this end, we study the lowest-lying singlet and triplet states of neutral annulenes with an even number of carbon atoms between four and eighteen. First of all, we analyze these rules from the Hückel molecular orbital method and, afterwards, we perform a geometry optimization of the annulenes with several density functional approximations in order to analyze the effect that the distortions from planarity produce on the aromaticity of annulenes. Finally, we analyze the performance of three density functional approximations that employ different percentages of Hartree-Fock exchange (B3LYP, CAM-B3LYP and M06-2X) and Hartree-Fock. Our results reveal that functionals with a low percentage of Hartree-Fock exchange at long ranges suffer from severe delocalization errors that result in wrong geometrical structures and the overestimation of the aromatic character of annulenes.

Emission and Deactivation of the Excited States of 2,3-Pentanedione

1972 ◽  
Vol 50 (9) ◽  
pp. 1338-1344 ◽  
Author(s):  
A. W. Jackson ◽  
A. J. Yarwood
Keyword(s):  
Triplet State ◽  
Gas Phase ◽  
Excited States ◽  
Singlet State ◽  
Triplet States ◽  
Excited Singlet ◽  
Vibrationally Excited ◽  
Singlet Level ◽  
Singlet And Triplet States ◽  
Fluorescence And Phosphorescence

Vibrationally excited singlet and triplet states of 2,3-pentanedione are formed by photolysis at 365 nm. The processes removing these excited states in the gas phase are studied by measuring the fluorescence and phosphorescence yields. Fluorescence can occur from the vibrationally excited, as well as the vibrationally equilibrated, singlet state. The fluorescence and phosphorescence data are considered in terms of mechanisms which involve either weak or strong collisions. Although the data cannot distinguish between the alternatives, there are two significant conclusions. The fluorescence data require that emission occur from at least two levels in the singlet manifold. To explain the phosphorescence data, the highest emitting singlet level must not lead to a vibrationally equilibrated triplet state.

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