DFT Study of Substituted Effect on Absorption and Emission Spectra of Naphthoquinone Derivatives

2011 ◽  
Vol 233-235 ◽  
pp. 1878-1883 ◽  
Author(s):  
Li Zhi Wang ◽  
Run Zhou Su ◽  
Shuo Qi ◽  
Wei Yu Gong ◽  
Tai Min Cheng
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Visible Region ◽  
Emission Spectra ◽  
Electron Transition ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
The Density Functional Theory ◽  
Substituted Effect

The density functional theory (DFT) is used to compute the ground-state geometries of naphthoquinone derivatives, and lowest singlet excited-state geometries of them have been investigated by the singles configuration interaction (CIS) method. The absorption and emission spectra are calculated by time-dependent DFT (TDDFT) on the basis of the ground- and excited-state geometries, respectively. Our calculations are in good agreement with the available experimental results. The calculated results show that with the introduction of hydroxyl the red-shift was found in the absorption and emission, and the range of spectra reach the visible region. Furthermore, in the absorptions electron transition type was identified from the point-view of molecular orbitals. Study of the effect of hydroxyl and site on spectra can provide the helpful information on further designing molecular devices.

scholarly journals Quantum Chemical Study Aimed at Modeling Efficient Aza-BODIPY NIR Dyes: Molecular and Electronic Structure, Absorption, and Emission Spectra

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5361
Author(s):  
Alexander E. Pogonin ◽  
Artyom Y. Shagurin ◽  
Maria A. Savenkova ◽  
Felix Yu. Telegin ◽  
Yuriy S. Marfin ◽  
...  
Keyword(s):  
Density Functional ◽  
Quantum Chemical Study ◽  
Emission Spectra ◽  
Chemical Study ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Nir Dyes ◽  
Vibronic Couplings ◽  
Molecular And Electronic Structure

A comprehensive study of the molecular structure of aza-BODIPY and its derivatives, obtained by introduction of one or more substituents, was carried out. We considered the changes in the characteristics of the electronic and geometric structure of the unsubstituted aza-BODIPY introducing the following substituents into the dipyrrin core; phenyl, 2-thiophenyl, 2-furanyl, 3-pyridinyl, 4-pyridinyl, 2-pyridinyl, and ethyl groups. The ground-state geometries of the unsubstituted Aza-BODIPY and 27 derivatives were computed at the PBE/6-31G(d) and CAM-B3LYP/6-31+G(d,p) levels of theory. The time-dependent density-functional theory (TDDFT) together with FC vibronic couplings was used to investigate their absorption and emission spectra.

scholarly journals Laser performance and investigation of the optimal density functional and the dependence of the basis sets for (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) molecule

2021 ◽  
Vol 27 (9) ◽  
Author(s):  
Mahmoud A. S. Sakr ◽  
Sayed A. Abdel Gawad ◽  
Samy A. El-Daly ◽  
Maram T. H. Abou Kana ◽  
El-Zeiny M. Ebeid
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Sol Gel ◽  
Emission Spectra ◽  
Basis Sets ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Photophysical Parameters ◽  
Copolymer Matrices

AbstractThis manuscript includes some photophysical parameters and some optical properties such as absorption and emission spectra of the (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) by applying sol–gel and copolymer matrices. The BDP molecular structure is incorporated in sol–gel matrix and copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). In case of sol–gel matrix, the BDP molecular structure has higher quantum yield in addition to photostability maxima. The laser behavior of this molecular structure containing sol–gel matrix is good senior compared to copolymer one via using diode laser (450 nm) as pumping laser of power 160 mW. Also, the fluorescence profile of the BDP molecular structure is sensitized via using cadmium sulfide (CdS) quantum dots (QDs) by applying sol–gel host. The optimized structure of the BDP molecule is obtained via applying B3LYP/6-31G(d) level of theory. The electronic absorption and emission spectra of the BDP molecular structure in ethanol solvent were calculated using time-dependent density functional theory (TDDFT) at CAM-B3LYP/6-31G +  + (d, p) level. The obtained theoretical results were compared to experimental ones.

Spectroscopic Properties Calculation of some 1, 8-Naphthalimide Derivatives

2013 ◽  
Vol 760-762 ◽  
pp. 724-727
Author(s):  
Qi Qi ◽  
Fan Qi ◽  
Yu Qiao Wang ◽  
Zheng Jian Qi ◽  
Yue Ming Sun
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Emission Spectra ◽  
Spectroscopic Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Dependent Density ◽  
Singlet Transition

The absorption and emission spectra of 1,8-naphthalimide derivatives have been calculated by time-dependent density functional theory. Their lowest singlet transition states can be described as the promotion of electrons from the HOMO to the LUMO. Substituents on naphthalimic ring seldom extend the conjugation of the central naphthalimic system.

Structures and Absorption Spectrum of 1D and 2D ZnS Nanoparticles

2020 ◽  
Vol 5 (1) ◽  
pp. 26-35
Author(s):  
Spyros Papantzikos ◽  
Alexandos G. Chronis ◽  
Fotios I. Michos ◽  
Mihail M. Sigalas
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Toxic Elements ◽  
Visible Region ◽  
Visible Spectrum ◽  
Zns Nanoparticles ◽  
Major Drawback ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Optimized Geometries

Background: ZnS nanoparticles (NPs) are attractive for quantum dots applications because they consist of abundant and non-toxic elements. Their major drawback is that they absorb in the UV region, ultimately limiting their applications. Objective: In the present study, 1D and 2D ZnS NPs have been found. The goal of this study is to find NPs that have absorption in the visible spectrum. Methods: Calculations based on the Density Functional Theory (DFT) have been used to find the optimized geometries. Their absorption spectra have been calculated with the Time-Dependent DFT. Results: Several shapes were examined, such as nanorod, and it is observed that these shapes move the absorption spectra in lower energies, into the visible spectrum, while the 3D NPs have absorption edges in the UV region. Conclusion: NPs with the shape of nanorod in different directions showed that their absorption spectra moved to lower energies well inside the visible spectrum with significantly high oscillator strength. In contrast with the mostly used CdSe NPs, the ZnS NPs are made from more abundant and less toxic elements. Therefore, by making them absorb in the visible region, they may find significant applications in solar cells and other photonic applications.

An analogy study on ESIPT reaction for 3BHC sensor between polar DMF and nonpolar toluene

2017 ◽  
Vol 95 (12) ◽  
pp. 1303-1307
Author(s):  
Dapeng Yang ◽  
Min Jia ◽  
Jingyuan Wu ◽  
Xiaoyan Song ◽  
Qiaoli Zhang
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Emission Spectra ◽  
Dft Method ◽  
Intramolecular Proton Transfer ◽  
Nonpolar Solvent ◽  
State Behavior ◽  
Functional Theory ◽  
Td Dft ◽  
Intramolecular Hydrogen

A comparison about excited state intramolecular proton transfer (ESIPT) mechanism of a new sensor 3-(1,3-benzothiazol-2-yl)-2-hydroxynaphthalene-1-carbaldehyde (3BHC) in polar solvent dimethylformamide (DMF) and nonpolar solvent toluene have been investigated within the framework of the time-dependent density functional theory (TD-DFT) method. The reproduced previous experimental absorption and emission spectra via our calculations reveals the reasonability of the DFT and TD-DFT theoretical level. The staple bond lengths, bond angles, and corresponding infrared vibrational spectra demonstrate that the intramolecular hydrogen bond of 3BHC should be strengthened in both polar DMF and nonpolar toluene. Two kinds of ESIPT mechanisms for different solvents have been put forward; there is a low potential barrier in the ESIPT process in the DMF solvent, whereas there is almost a nonbarrier for the ESIPT process in the toluene solvent. Hence, we could conclude that the ESIPT process of 3BHC sensor is more likely to occur in the nonpolar solvent upon the photoexcitation, based on which, the excited state behavior of 3BHC could be controlled.

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