Molecular Modelling of Ground- and Excited-States Vibrations in Organic Conducting Devices: Hexakis(n-hexyloxy)triphenylene (HAT6) as Case Study

2010 ◽  
Vol 63 (3) ◽  
pp. 388 ◽  
Author(s):  
M. Zbiri ◽  
M. R. Johnson ◽  
L. Haverkate ◽  
F. M. Mulder ◽  
G. J. Kearley
Keyword(s):  
Excited State ◽  
Electronic State ◽  
Ground State ◽  
Density Functional ◽  
Excited Electronic State ◽  
Molecular Vibrations ◽  
Functional Theory ◽  
Model Calculations ◽  
Insight Into

In order to gain insight into fundamental aspects of organic photocell materials, we have calculated ground and excited electronic-state structures and molecular vibrations for an isolated HAT6 molecule (hexakis(n-hexyloxy)triphenylene). Excited-state calculations are carried out using time-dependent density functional theory and frequencies are evaluated analytically using coupled perturbed Kohn–Sham equations. These model calculations have been validated against new infrared and ultraviolet data on HAT6 in solution. The main allowed valence excitation, having the largest oscillator strength, is chosen for the structural and vibrational investigations. Comparison with the ground-state vibrational dynamics reveals surprisingly large spectral differences. In addition, the alkoxy tails, which are usually considered to play only a structural role, are clearly involved in the molecular vibrations and the structural distortion of the excited electronic state compared with the ground state. The tails may play a more important role in charge separation, transport and excited-state relaxation than was previously thought. In this case, chemical modification of the tails would allow vibrational and related properties of organic photocell materials to be tailored.

Accurate description of hybridized local and charge-transfer excited-state in donor–acceptor molecules using density functional theory

RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108404-108410 ◽  
Author(s):  
Y. Y. Pan ◽  
J. Huang ◽  
Z. M. Wang ◽  
S. T. Zhang ◽  
D. W. Yu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Charge Transfer ◽  
Ground State ◽  
Density Functional ◽  
Accurate Description ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Acceptor Molecules

The ωB97X was the most reliable functional for the accurate description of HLCT state at ground state and excited state.

Relaxed structure of typical nitro explosives in the excited state: observation and implication

2017 ◽  
Author(s):  
Genbai Chu
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Nitro Group ◽  
Density Functional ◽  
Functional Theory ◽  
Chemical Mechanisms ◽  
State Observation ◽  
Nitro Explosives ◽  
Physical And Chemical ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent physical and chemical mechanisms of nitro explosives. In this work, the relaxed structure of some typical nitro explosives in the excited state, including RDX, HMX, CL-20, PETN and LLM-105, have been investigated by time-dependent density functional theory. During the excitation process, an electron is vertically excited into a low-lying excited state, imparting π-antibonding character onto the nitro group. The nitro group becomes activated by the excitation energy and then relaxes via vibrational cooling, leading to a relaxed excited-state structure. </a><a></a><a>All five nitro explosives exhibit similar behavior in which impact sensitivity is related to the excitation energy of the relaxed structure.</a> <a></a><a>Insight into the relaxed structure of typical nitro explosives offers an efficient method of unraveling ultrafast and complex photo-initiated reactions and detonation physics</a>.

Graphyne and graphdiyne: theoretical insight into ground and excited state properties

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89934-89939 ◽  
Author(s):  
Siddheshwar Chopra
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Carbon Allotropes ◽  
Theoretical Insight ◽  
Insight Into ◽  
Dependent Density

The ground and excited state properties of the two carbon allotropes, graphyne (C66H18) (gr1) and graphdiyne (C90H18) (gr2), in the form of nanoflakes were studied with the help of density functional theory (DFT) and time dependent density functional theory (TDDFT).

Relaxed structure of typical nitro explosives in the excited state: observation, implication and application

2017 ◽  
Author(s):  
Genbai Chu ◽  
Zuhua Yang ◽  
Tao Xi ◽  
Jianting Xin ◽  
Yongqiang Zhao ◽  
...  
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Density Functional ◽  
Energetic Material ◽  
Functional Theory ◽  
State Observation ◽  
Lower Excitation Energy ◽  
Nitro Explosives ◽  
Lower Excitation ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent mechanism of nitro explosives. In this work, relaxed structures of typical nitro explosives in the excited state are investigated by time-dependent density functional theory. During the excitation process, nitro group becomes activated and then relaxes, leading to a relaxed structure. </a><a></a><a>All five nitro explosives exhibit a similar behavior, and impact sensitivity is related to excitation energy of relaxed structure.</a> <a></a><a>H</a>igh sensitivity d-HMX has a lower excitation energy for relaxed structure than b-HMX. This work offers a novel insight into energetic material.<a></a>

Relaxed structure of typical nitro explosives in the excited state: observation and implication

2017 ◽  
Author(s):  
Genbai Chu
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Nitro Group ◽  
Density Functional ◽  
Functional Theory ◽  
Chemical Mechanisms ◽  
State Observation ◽  
Nitro Explosives ◽  
Physical And Chemical ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent physical and chemical mechanisms of nitro explosives. In this work, the relaxed structure of some typical nitro explosives in the excited state, including RDX, HMX, CL-20, PETN and LLM-105, have been investigated by time-dependent density functional theory. During the excitation process, an electron is vertically excited into a low-lying excited state, imparting π-antibonding character onto the nitro group. The nitro group becomes activated by the excitation energy and then relaxes via vibrational cooling, leading to a relaxed excited-state structure. </a><a></a><a>All five nitro explosives exhibit similar behavior in which impact sensitivity is related to the excitation energy of the relaxed structure.</a> <a></a><a>Insight into the relaxed structure of typical nitro explosives offers an efficient method of unraveling ultrafast and complex photo-initiated reactions and detonation physics</a>.

Solvent effect on electron and proton transfer in the excited state of a hydrogen bonded phenol–imidazole complex

RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38551-38557 ◽  
Author(s):  
Baotao Kang ◽  
Hu Shi ◽  
Shihai Yan ◽  
Jin Yong Lee
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Photosystem Ii ◽  
Ground State ◽  
Active Site ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Model System ◽  
Functional Theory ◽  
First Excited State

Density functional theory calculations have been carried out for the ground state (S0) and the first excited state (S1) of the H-bonded phenol and imidazole complex as a model system for the active site of photosystem II.

scholarly journals Mechanistic Insight into SARS-CoV-2 Mpro Inhibition by Organoselenides: The Ebselen Case Study

2021 ◽  
Vol 11 (14) ◽  
pp. 6291
Author(s):  
Andrea Madabeni ◽  
Pablo Andrei Nogara ◽  
Folorunsho Bright Omage ◽  
João Batista Teixeira Rocha ◽  
Laura Orian
Keyword(s):  
Density Functional ◽  
Rational Drug Design ◽  
Functional Theory ◽  
Main Protease ◽  
Rational Drug ◽  
Mechanistic Investigation ◽  
Pharmacologically Active ◽  
First Time ◽  
Insight Into

The main protease (Mpro) of SARS-CoV-2 is a current target for the inhibition of viral replication. Through a combined Docking and Density Functional Theory (DFT) approach, we investigated in-silico the molecular mechanism by which ebselen (IUPAC: 2-phenyl-1,2-benzoselenazol-3-one), the most famous and pharmacologically active organoselenide, inhibits Mpro. For the first time, we report on a mechanistic investigation in an enzyme for the formation of the covalent -S-Se- bond between ebselen and a key enzymatic cysteine. The results highlight the strengths and weaknesses of ebselen and provide hints for a rational drug design of bioorganic selenium-based inhibitors.

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