Theoretical Investigation on the Structure and Optical Properties of Alq3 and its Difluorinated Derivatives

2011 ◽  
Vol 287-290 ◽  
pp. 1526-1531 ◽  
Author(s):  
Xiao Cun Liu ◽  
Yan Ju Ji ◽  
Gang Fu ◽  
Feng Xiang Wang ◽  
Ying Chen ◽  
...  
Keyword(s):  
Ground State ◽  
Density Functional ◽  
Emission Spectra ◽  
Blue Shift ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Reorganization Energies ◽  
Electron Carriers ◽  
Significant Blue Shift

The structures of tris(8-hydroxyquinoline) aluminum (Alq3) and its difluorinated derivatives were optimized for the ground state at the B3LYP/6-31G* level and for the excited-state at the CIS/6-31G* level. At the same time, the absorption and emission spectra based on the above structures were calculated by the time-dependent density functional theory (TD-DFT) using the PBE0 method with the 6-31G* set. A significant red shift was predicted for 3,5-difluoro-substituted Alq3 while a significant blue shift for 4,6-difluoro-substituted Alq3. In addition, the reorganization energies for electron carriers (λe) were predicted and it was found that the derivatives are potential materials for electron transport.

Luminescence properties and optimized structural conformations of the S0, S1 and T1 states of a tetranuclear formamidinate complex based on AuI and AgI metal ions

2019 ◽  
Vol 75 (7) ◽  
pp. 985-989
Author(s):  
Wayne Hsu
Keyword(s):  
Metal Ions ◽  
Excited States ◽  
Ground State ◽  
Density Functional ◽  
Metal Salts ◽  
Time Dependent ◽  
Functional Theory ◽  
Planar Conformation ◽  
Ligand Charge Transfer ◽  
Td Dft

N,N′-Bis(pyridin-4-yl)formamidine (4-pyfH) was reacted with AuI and AgI metal salts to form a novel tetranuclear complex, tetrakis[μ-N,N′-bis(pyridin-4-yl)formamidinato]digold(I)disilver(I), [Ag2Au2(C11H9N4)2] or [Au x Ag4–x (4-pyf)4] (x = 0–4), 1, which is supported by its metallophilicity. Due to the potential permutation of the coordinated metal ions, six different canonical structures of 1 can be obtained. Complex 1 shows an emission at 501 nm upon excitation at 375 nm in the solid state and an emission at 438 nm upon excitation at 304 nm when dispersed in methanol. Time-dependent density functional theory (TD-DFT) calculations confirmed that these emissions can be ascribed to metal-to-ligand charge transfer (MLCT) processes. Moreover, the calculations of the optimized structural conformations of the S0 ground state, and the S1 and T1 excited states are discussed and suggest a distorted planar conformation for the tetranuclear Au2Ag2 complex.

scholarly journals Modelling absorption and emission of a meso-aniline–BODIPY based dye with molecular mechanics

2018 ◽  
Vol 20 (21) ◽  
pp. 14537-14544 ◽  
Author(s):  
Flip de Jong ◽  
Milica Feldt ◽  
Jonas Feldt ◽  
Jeremy N. Harvey
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Emission Spectra ◽  
Time Dependent ◽  
Coupled Cluster ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Td Dft ◽  
P Absorption ◽  
Dependent Density

Absorption and emission spectra of 8-(4-dimethylaminophenyl)-1,3,5,7-tetramethyl–BODIPY have been calculated using Coupled Cluster (CC) approaches, Time-Dependent Density Functional Theory (TD-DFT) and a QM-informed MM approach.

Second order hyperpolarizability of triphenylamine based organic sensitizers: a first principle theoretical study

RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75242-75250 ◽  
Author(s):  
M. Prakasam ◽  
P. M. Anbarasan
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Theoretical Study ◽  
Time Dependent ◽  
First Principle ◽  
Functional Theory ◽  
Metal Free ◽  
Td Dft ◽  
Organic Sensitizers

Designed metal-free dyes have been investigated by Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) to evaluate the ground state and excited state geometries of triphenylamine-based organic sensitizers.

DFT/TD-DFT Studies on the Lawsone (Henna) as a Photosensitizer for Dye-Sensitized Solar Cells

2015 ◽  
Vol 789-790 ◽  
pp. 56-60 ◽  
Author(s):  
May Win Han ◽  
Piyasiri Ekanayake ◽  
Lim Chee Ming ◽  
Voo Nyuk Yoong
Keyword(s):  
Optical Properties ◽  
Ground State ◽  
Electronic Structures ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Time Dependent ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Sensitized Solar Cells

In this study, the parameters of the photo-electrochemical properties, such as the ground state geometries, excitation energy, electronic structures, optical properties and electronics transition of lawsone were investigated by using density functional theory ( DFT ) and time dependent - DFT with B3LYP/6-31G( d) method. The solvent effect was considered in the DFT calculations and compared with the value of vacuum. From the analyses of electronic and optical properties, it is found that the lawsone satisfy the condition for good conversion efficiency as DSSCs device.

Photophysical Properties of N-Methyl and N-Acetyl Substituted Alloxazine: A Theoretical Investigation

2021 ◽  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...

Spectroscopic trends in a series of Re(I) α-diimine complexes as a function of the antenna/photoisomerizable ligands: a TD-DFT and MS-CASPT2 study

2014 ◽  
Vol 92 (10) ◽  
pp. 979-986 ◽  
Author(s):  
Megumi Kayanuma ◽  
Chantal Daniel ◽  
Etienne Gindensperger
Keyword(s):  
Excited States ◽  
Electronic Structures ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
B3lyp Level ◽  
Ligand Charge Transfer ◽  
Td Dft ◽  
Energy Domain ◽  
Diimine Complexes

The absorption spectra of 11 rhenium(I) complexes with photoisomerizable stilbene-like ligands have been investigated by means of density functional theory (DFT). The electronic structures of the ground and excited states were determined for [Re(CO)3(N,N)(L)]+ (N,N = bpy (2,2′-bipyridine), phen (1,10-phenanthroline), Me4phen (3,4,7,8-tetramethyl-1,10-phenanthroline), ph2phen (4,7-diphenyl-1,10-phenanthroline), or Clphen (5-chloro-1,10-phenanthroline); L = bpe (1,2-bis(4-pyrydil)ethylene), stpy (4-styrylpyridine), or CNstpy (4-(4-cyano)styrylpyridine)) at the time–dependent (TD) DFT/CAM-B3LYP level of theory in vacuum and acetonitrile to highlight the effects of both antenna N,N and isomerizable L ligands. The TD-DFT spectra of two representative complexes, namely [Re(CO)3(bpy)(stpy)]+ and [Re(CO)3(phen)(bpe)]+, have been compared with MS-CASPT2 spectra. The TD-DFT spectra obtained in vacuum and acetonitrile agree rather well both with the ab initio and experimental spectra. The absorption spectroscopy of this series of molecules is characterized by the presence of three low-lying metal to ligand charge transfer (MLCT) states absorbing in the visible energy domain. The nature of the isomerizable ligands (bpe, stpy, or CNstpy) and the type of antenna ligands (bpy, phen, and substituted phen) control the degree of mixing between the MLCT and intraligand excited states, their relative energies, as well as their intensities.

Theoretical investigation of the electronic structure and photophysical properties of a series of Ir(iii) complexes bearing pentafluorosulfanyl groups

2019 ◽  
Vol 43 (25) ◽  
pp. 9916-9923 ◽  
Author(s):  
Jing Gao ◽  
Xin Li ◽  
Deming Han ◽  
Jiawei Li ◽  
Xiaohong Shang
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Time Dependent ◽  
Functional Theory ◽  
Ancillary Ligands ◽  
Dependent Density

The electronic structure, absorption and emission spectra, charge injection/transport ability and phosphorescence quantum efficiency of a series of cyclometalated iridium(iii) complexes with different ancillary ligands are studied using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods.

Comparative DFT study for molecular geometries and spectra of methyl pheophorbides-a: test of M06-2X and two other functionals

2010 ◽  
Vol 14 (07) ◽  
pp. 592-604 ◽  
Author(s):  
Do Sung Huh ◽  
Sang Joon Choe
Keyword(s):  
Density Functional Theory ◽  
Standard Deviation ◽  
Density Functional ◽  
Visible Spectrum ◽  
Mean Value ◽  
Time Dependent ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
The Mean

The recent interest in the application of density functional theory (DFT) has prompted us to test several functions in molecular geometries of methyl pheophorbides-a (MPa), an important starting material in photodynamic therapy (PDT). In this study, we report on tests for three popular DFT methods: M06-2X, B3LYP, and LSDA. Based on the standard deviation and the mean value, and by using the difference between optimized calculated value and experimental value in geometries, we drew the following conclusions: M06-2X/6-311+G(d,p) attained the smallest standard deviation of difference among the tested DFT methods in terms of bond length, whereas the standard deviation of bond angle in LSDA/6-311+G(d,p) was the smallest. In terms of absolute value, the mean value of LSDA/6-311+G(d,p) calculation was larger than that of M06-2X/6-311+G(d,p). We found that M06-2X/6-311+G(d,p) gave the best performance for MPa in the molecular geometries. The UV-visible spectrum was calculated with time-dependent density-functional theory (TD-DFT). Time-dependent M06-2X/6-311+G(d,p) gave the best performance for MPa in CH2Cl2 solution. In general, TD-DFT calculations in CH2Cl2 solution were more red-shifted compared with those in the solid state.

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