scholarly journals Theoretical Studies of Electronic Structure and Photophysical Properties of a Series of Indoline Dyes with Triphenylamine Ligand

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xue-Feng Ren ◽  
Jun Zhang ◽  
Guo-Jun Kang
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Photophysical Properties ◽  
Energy Levels ◽  
Dye Sensitized Solar Cells ◽  
Dft Method ◽  
Structure Property ◽  
Lumo Energy ◽  
Semiconductor Interface ◽  
Homo And Lumo

To design efficient organic sensitizer, a series of D-π-A indoline dyes with different donor parts have been investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) approach. The molecular geometries, frontier molecular orbitals, and absorption spectra of these dyes have been systematically investigated to provide comprehensive understanding of the structure-property relationships. Compared with D149, our designed dyes have proper HOMO and LUMO energy level, narrowed HOMO-LUMO energy gap, and broadened absorption band by introducing the N(CH3)2and N(phenyl)2groups at the donor part. Furthermore, the dimeric dyes and dye-(TiO2)6systems have been optimized by DFT method to simulate the intermolecular interactions, as well as interaction between the dyes dimmers and semiconductor interface, respectively. Through the analyses of absorption energies (Eads), energy levels of the HOMO and LUMO, light harvesting efficiency (LHE), and the driving force of electrons injections (ΔGinject), it is found that the designed dyes should have improved optical properties by importing the N(CH3)2group. This work is hoped to provide a theoretical guiding role in design of new dyes for dye-sensitized solar cells.

Synthesis, crystal structure, DFT studies and photophysical properties of a copper(I)–triphenylphosphane complex based on trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline

2017 ◽  
Vol 73 (3) ◽  
pp. 280-286 ◽  
Author(s):  
Alberto Báez-Castro ◽  
Jesús Baldenebro-López ◽  
Laura Ceballos-Mendivil ◽  
Perla P. Román-Bravo ◽  
Herbert Höpfl ◽  
...  
Keyword(s):  
Density Functional ◽  
Photophysical Properties ◽  
Dye Sensitized Solar Cells ◽  
The Novel ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
H Nmr ◽  
Dye Sensitized ◽  
Homo And Lumo ◽  
Sensitized Solar Cells

The possibility of using less expensive and nontoxic metals, such as copper, as substitutes for more expensive heavy metals in the synthesis of new transition-metal complexes to be used as sensitizers in dye-sensitized solar cells (DSSCs) has stimulated research in this field. The novel photoluminescent copper(I) complex bis(triphenylphosphane-κP)[trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline-κ2 N 2,N 3]copper(I) hexafluorophosphate, [CuI(C18H15N5)(C18H15P)2]PF6, has been successfully synthesized and characterized by IR and 1H NMR spectroscopy, as well as by single-crystal X-ray diffraction and thermogravimetric analysis. The complex showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV–Vis and fluorescence spectroscopy. Density functional theory (DFT) calculations with dichloromethane as solvent reproduced reasonably well the HOMO and LUMO orbitals of the title compound.

scholarly journals Theoretical modeling of optical spectra of N(1) and N(10) substituted lumichrome derivatives

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Denisa Cagardová ◽  
Jan Truksa ◽  
Martin Michalík ◽  
Jan Richtár ◽  
Jozef Krajčovič ◽  
...  
Keyword(s):  
Density Functional ◽  
Optical Transition ◽  
Photophysical Properties ◽  
Energy Levels ◽  
Dft Method ◽  
Functional Theory ◽  
Transition Energies ◽  
The Density Functional Theory ◽  
Td Dft

AbstractA systematic study of (7,8-dimethylated) alloxazine, isoalloxazine, and their derivatives with substituted N(1) and N(10) positions was conducted using the density functional theory. The main aim of this work was the direct investigation of substituent effect on the molecular structure. Furthermore, HOMED aromaticity indices were calculated to describe the scope of the geometry changes. Frontier molecular orbitals of reference alloxazine, isoalloxazine and lumichrome derivatives were discussed by means of changes in their shape and energy levels. Photophysical properties were analyzed by determination of optical transition energies using the TD-DFT method. Obtained results were compared with previously published experimental data.

Properties of Fluorene Derivatives: DFT Investigation

2012 ◽  
Vol 532-533 ◽  
pp. 97-100
Author(s):  
Bo Wei Chen ◽  
Guan Jun Chang ◽  
Lin Zhang
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
Electronic Structures ◽  
Energy Levels ◽  
Dft Method ◽  
Semiconductor Materials ◽  
Density Functions ◽  
Lumo Energy ◽  
Homo And Lumo ◽  
Homo And Lumo Energy

Fluorene derivatives are typical semiconductor materials. The electronic structures of Fluorene derivatives were successfully investigated by density functions theory (DFT). Furthermore, the HOMO and LUMO energy levels will be changed owing to the introduction of some aliphatic chains in the fluorene. So through theoretical investigation of electronic structure and molecule orbit by the DFT method, the variational UV-vis absorption spectra of fluorene derivatives due to variational levels were explained.

A Theoretical Design of a New Organic Dye Containing Coronene for Dye-Sensitized Solar Cells

2018 ◽  
Vol 2 (1) ◽  
pp. 30-32
Author(s):  
Hammood M. Yasir ◽  
Falah H. Hanoon
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Energy Levels ◽  
Dye Sensitized Solar Cells ◽  
Organic Dye ◽  
Basis Set ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

In search of novel high-performance materials for use in dye-sensitized solar cells (DSSCs), we used density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to study the geometry, electronic, and optical properties, for organic molecules. The enhancement of organic dye was done by the terminal addition with organic molecule in order to improve their electronic properties and optical absorption. The absorption is became higher than that of the original dye where the rising absorption from 1050 to 1350 approximately. Also, we found that the B3LYP functional with the 6-31G basis set gave highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels. The energy gap decreased after addition from 2.73 to 2.52 eV.

Tuning the HOMO and LUMO Energy Levels of Organic Chromophores for Dye Sensitized Solar Cells

2007 ◽  
Vol 72 (25) ◽  
pp. 9550-9556 ◽  
Author(s):  
Daniel P. Hagberg ◽  
Tannia Marinado ◽  
Karl Martin Karlsson ◽  
Kazuteru Nonomura ◽  
Peng Qin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Energy Levels ◽  
Dye Sensitized Solar Cells ◽  
Lumo Energy ◽  
Organic Chromophores ◽  
Dye Sensitized ◽  
Homo And Lumo ◽  
Sensitized Solar Cells ◽  
Homo And Lumo Energy

Molecular Investigations of the Newly Synthesized Azomethines as Antioxidants: Theoretical and Experimental Studies

2019 ◽  
Vol 19 (6) ◽  
pp. 419-433 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Liudmila Filippovich ◽  
Evgenij Dikusar ◽  
Anhelina Pazniak ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Experimental Studies ◽  
Antioxidant Property ◽  
Nbo Analysis ◽  
Antioxidant Potential ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Intramolecular Hydrogen ◽  
Activity Mechanism

: In this study, the antioxidant property of new synthesized azomethins has been investigated as theoretical and experimental. Methods and Results: Density functional theory (DFT) was employed to investigate the Bond Dissociation Enthalpy (BDE), Mulliken Charges, NBO analysis, Ionization Potential (IP), Electron Affinities (EA), HOMO and LUMO energies, Hardness (η), Softness (S), Electronegativity (µ), Electrophilic Index (ω), Electron Donating Power (ω-), Electron Accepting Power (ω+) and Energy Gap (Eg) in order to deduce scavenging action of the two new synthesized azomethines (FD-1 and FD-2). Spin density calculations and NBO analysis were also carried out to understand the antioxidant activity mechanism. Comparison of BDE of FD-1 and FD-2 indicate the weal antioxidant potential of these structures. Conclusion: FD-1 and FD-2 have very high antioxidant potential due to the planarity and formation of intramolecular hydrogen bonds.

Spectroscopic investigations and DFT studies of synthesized 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate a novel conjugate of gallic acid

2020 ◽  
Vol 17 ◽  
Author(s):  
Sangeeta Srivastava ◽  
Nadeem Ahmad Ansari ◽  
Sadaf Aleem
Keyword(s):  
Gallic Acid ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Major Constituent ◽  
Orbital Energy ◽  
Reactivity Descriptors ◽  
Homo And Lumo ◽  
Electrophilic Reactivity ◽  
Global And Local

: Gallic acid is abundantly found in amla (Phyllanthus emblica), a deciduous of the family phyllanthaceae. Gallic acid, the major constituent of the plant was methylated to 3,4,5 trimethoxy gallic acid, which then underwent steglich esterification first with paracetamol and then with 4-hydroxy acetophenone to yield 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate “respectively”. 1H NMR, 13C NMR, UV, FT-IR and mass spectroscopy were used to characterize the synthesized compounds. Density functional theory (B3YLP) using 6-31G (d,p) basis set have been used for quantum chemical calculations. AIM (Atom in molecule) approach depicted weak molecular interactions within the molecules whereas the reactive site and reactivity within the molecule were examined by global and local reactivity descriptors. The HOMO and LUMO energies and frontier orbital energy gap were calculated by time dependant DFT approach using IEFPCM model. Small value for HOMO–LUMO energy gap indicated that easier charge transfer occurs within compound 4. The nucleophilic and electrophilic reactivity were determined by MEP (molecular electrostatic potential) experiment. Polarizability, dipole moment, and first hyperpolarizability values were calculated to depict the NLO (nonlinear optical) property of both the synthesized compounds. The antimicrobial activity was also carried out and broad spectrum antibacterial activity against several strains of bacteria and certain unicellular fungi were exhibited by synthesized compound 3.

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

scholarly journals Electronic Structure of Two New Bis-Schiff Base Ligands using DFT Method

2021 ◽  
pp. 10-15
Author(s):  
Elham Abdalrahem Bin Selim ◽  
Mohammed Hadi Al–Douh ◽  
Hassan Hadi Abdullah ◽  
Dahab Salim Al–Nohey
Keyword(s):  
Experimental Data ◽  
Biological Activity ◽  
Metal Ion ◽  
Energy Levels ◽  
Dft Method ◽  
Ftir Spectra ◽  
Schiff Base Ligands ◽  
Lumo Energy ◽  
Homo Lumo ◽  
Good Agreement

Two bis-Schiff Bases 1 and 2 are ligands that can coordinate with manganese metal to form stable complexes and have biological activity. Thermodynamic parameters, HOMO-LUMO energy levels and FTIR spectra of two ligands have been computed using B3LYP/6-311++G(d,p) functional of the DFT calculations. Both ligands are favored thermodynamically, and the ligand 1 has been shown to be more stable than ligand 2. The Polarizability values of two ligands have been investigated. The results refer that ligand 2 interacts earlier than ligand 1 to the metal ion. The FTIR spectra of two ligands have been evaluated. All results show the good agreement between the theoretical and experimental data.

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