scholarly journals TD-DFT Simulation and Experimental Studies of a Mirrorless Lasing of Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-diphenylene-vinylene-2-methoxy-5-{2-ethylhexyloxy}-benzene)]

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1430
Author(s):  
Mamduh J. Aljaafreh ◽  
Saradh Prasad ◽  
Mohamad S. AlSalhi ◽  
Raya H. Alhandel ◽  
Reem A. Alsaigh
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Experimental Studies ◽  
Optical Gain ◽  
Functional Theory ◽  
Time Resolved ◽  
Dft Simulation ◽  
Td Dft ◽  
Lowest Unoccupied Molecular Orbital ◽  
Benzene Toluene

In this work, we investigate the TD-DFT simulation, optical, and mirrorless laser properties of conjugated polymer (CP) Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-diphenylene-vinylene-2-methoxy-5-{2-ethylhexyloxy}-benzene)], also known as (PFO-co-PPV-MEHB) or ADS125GE. TD-DFT calculations were performed for three monomer units with truncated tails using time-dependent density functional theory (TD-DFT) calculations. The calculations showed a highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) structure and a very high oscillator strength of 6.434 for the singlet-singlet transition at 374.43 nm. Experimentally, the absorption and fluorescence spectra were examined at various concentrations in verity of solvents, such as benzene, toluene, and hexane. The experimental results obtained in hexane were comparable with theoretical UV-VIS spectra calculated under vacuum. Amplified spontaneous emission (ASE) spectra peaked at approximately 509 nm for CO PFO-co-PPV-MEHB in solution and were obtained at suitable concentrations and pump energies. Additionally, the photochemical stability of this CP and coumarin (C510) were compared. Time-resolved spectroscopy (TRS) studies with a sub-nanosecond resolution were performed for the CO under various pump energies. These results showed the excited state dynamics and single-pass optical gain of CO PFO-co-PPV-MEHB.

scholarly journals DFT/TD-DFT Framework of Mixed-Metal Complexes with Symmetrical and Unsymmetrical Bridging Ligands—Step-By-Step Investigations: Mononuclear, Dinuclear Homometallic, and Heterometallic for Optoelectronic Applications

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7783
Author(s):  
Dawid Zych
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Metal Complexes ◽  
Density Functional ◽  
Physical Parameters ◽  
Bridging Ligands ◽  
Functional Theory ◽  
Mixed Metal ◽  
Td Dft ◽  
Mixed Metal Complexes

Recently, mono- and dinuclear complexes have been in the interest of scientists due to their potential application in optoelectronics. Herein, progressive theoretical investigations starting from mononuclear followed by homo- and heterometallic dinuclear osmium and/or ruthenium complexes with NCN-cyclometalating bridging ligands substituted by one or two kinds of heteroaryl groups (pyrazol-1-yl and 4-(2,2-dimethylpropyloxy)pyrid-2-yl) providing the short/long axial symmetry or asymmetry are presented. Step-by-step information about the particular part that built the mixed-metal complexes is crucial to understanding their behavior and checking the necessity of their eventual studies. Evaluation by using density functional theory (DFT) calculations allowed gaining information about the frontier orbitals, energy gaps, and physical parameters of complexes and their oxidized forms. Through time-dependent density functional theory (TD-DFT), calculations showed the optical properties, with a particular emphasis on the nature of low-energy bands. The presented results are a clear indication for other scientists in the field of chemistry and materials science.

scholarly journals Direct Orange 26 Dye Environmental Degradation: Experimental Studies (UV, Mass and Thermal) in Comparison With Computational Exploration Hydrogen Bonding Analysis of TD-DFT Calculations

2021 ◽  
Author(s):  
Zahraa A. M. Abo-Ayad ◽  
Mohamed A. Zayed ◽  
Mahmoud A Noamaan
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Population Analysis ◽  
Experimental Studies ◽  
Calculated Data ◽  
Structure Stability ◽  
Vibrational Properties ◽  
Td Dft

Abstract The importance of this study stems from, it concentrates on new approach applying both practical and theoretical aspects to study structure stability of Direct orange dye 26 (DO26) as an important dye widely used for dyeing of cotton or viscose for red orange direct printing. The stable dyes are so difficult to remove, decolorized and/ or degrade, in pure solution or in wastewater samples, without using powerful removal environmental techniques electrochemical oxidations suggest and efficiently used in our Lab. Therefore, it is very important to compare between practical thermal and mass results as efficient techniques in studying dye stability, in comparison with theoretical results using Gaussian program for structural stability identification of DO26 dye, via careful inspection of various phenomena detected in its two symmetrical arms around urea center. Direct orange dye 26 (DO26) structure has been studied applying both practical spectroscopic and theoretical investigations. DFT-B3LYP/6-311++G(d,p) calculations and the electronic vibrational properties are performed to investigate its structure stability and consequently its degradation and removal from its environmental media. Correlation is found between experimental and calculated data. An intra-molecular hydrogen bonding interaction had been detected and characterized in dye skeleton. The hydrogen bonding present in the dye structure affecting its vibrational properties had been discussed. Natural population analysis like HOMO and LUMO and high quality molecular electrostatic potential plots along with various electronics had been presented at the same level of theory. Chemical reactivity descriptors from conceptual density functional theory point of view, structure activity relationship descriptor were obtained. The experimental UV/Visible, FT-IR, mass and GC-mass spectral data of the dye DO26 (D1) had been presented. These data had been supported by TD-DFT calculations to simulate the experimental spectra with computing the natural transition orbitals (NTO) and the orbital composition. The variation of charge transfer length (Δr) and variation in its dipole moment with respect to ground state (ΔmCT) had been computed in order to study the charge redistribution due to the excitations. Actually there is a problem that, degradation of this dye in wastewater by different techniques leads to various unknown fragments but on using theoretical possibilities it can be expected what happened in practical work.

Time dependent-density functional theory (TD-DFT) and experimental studies of UV–Visible spectra and cyclic voltammetry for Cu(II) complex with Et2DTC

2018 ◽  
Vol 1157 ◽  
pp. 463-468 ◽  
Author(s):  
Eliana Maira A. Valle ◽  
Vinicius Gonçalves Maltarollo ◽  
Michell O. Almeida ◽  
Kathia Maria Honorio ◽  
Mauro Coelho dos Santos ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cyclic Voltammetry ◽  
Density Functional ◽  
Experimental Studies ◽  
Time Dependent ◽  
Functional Theory ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible ◽  
Dependent Density

Theoretical screening of promising donor and π-linker groups for POM-based Zn–porphyrin dyes in dye-sensitized solar cells

2019 ◽  
Vol 21 (7) ◽  
pp. 3822-3831 ◽  
Author(s):  
Yu Gao ◽  
Wei Guan ◽  
Likai Yan ◽  
Yanhong Xu
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Dft Calculations ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Time Dependent ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Sensitized Solar Cells

A series of Zn–porphyrin dyes with different donor and π-linker groups based on the dye SM315 were systematically investigated to screen highly efficient candidates based on density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations.

scholarly journals Photochemical α-Cleavage Reaction of 3’,5’-Dimethoxybenzoin: A Combined Time-Resolved Spectroscopy and Computational Chemistry Study

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3548
Author(s):  
Yuanchun Li ◽  
Xiting Zhang ◽  
Zhiping Yan ◽  
Lili Du ◽  
Wenjian Tang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Quantum Yield ◽  
Dft Calculations ◽  
Density Functional ◽  
Transient Absorption ◽  
Type I ◽  
Functional Theory ◽  
Time Resolved ◽  
Norrish Type ◽  
Intramolecular Hydrogen

Benzoin is one of the most commonly used photoinitiators to induce free radical polymerization. Here, improved benzoin properties could be accomplished by the introduction of two methoxy substituents, leading to the formation of 3’,5’-dimethoxybenzoin (DMB) which has a higher photo-cleavage quantum yield (0.54) than benzoin (0.35). To elucidate the underlying reaction mechanisms of DMB and obtain direct information of the transient species involved, femtosecond transient absorption (fs-TA) and nanosecond transient absorption (ns-TA) spectroscopic experiments in conjunction with density functional theory/time-dependent density functional theory (DFT/TD-DFT) calculations were performed. It was found that the photo-induced α-cleavage (Norrish Type I reaction) of DMB occurred from the nπ* triplet state after a rapid intersystem crossing (ISC) process (7.6 ps), leading to the generation of phenyl radicals on the picosecond time scale. Compared with Benzoin, DMB possesses two methoxy groups which are able to stabilize the alcohol radical and thus result in a stronger driving force for cleavage and a higher quantum yield of photodissociation. Two stable conformations (cis-DMB and trans-DMB) at ground state were found via DFT calculations. The influence of the intramolecular hydrogen bond on the α-cleavage of DMB was elaborated.

Three zinc iodide complexes based on phosphane ligands: syntheses, structures, optical properties and TD–DFT calculations

2018 ◽  
Vol 74 (3) ◽  
pp. 342-350 ◽  
Author(s):  
Di Chen ◽  
Qiu-Hua Wang ◽  
Wen-Xiang Chai ◽  
Li Song
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Light Emission ◽  
X Ray Diffraction ◽  
Thermal Stabilities ◽  
Functional Theory ◽  
Ligand Charge Transfer ◽  
Td Dft ◽  
Halide Ligand ◽  
Zinc Iodide

Three zinc iodide complexes based on phosphane ligands, namely diiodidobis(triphenylphosphane-κP)zinc(II), [ZnI2(C18H15P2)2], (1), diiodidobis[tris(4-methylphenyl)phosphane-κP]zinc(II), [ZnI2(C21H21P2)2], (2), and [bis(diphenylphosphoryl)methane-κ2O,O′]zinc(II) tetraiodidozinc(II), [Zn(C25H22O2P2)3][ZnI4], (3), have been synthesized and characterized. Single-crystal X-ray diffraction revealed that the structures of (1) and (2) are both mononuclear four-coordinated ZnI2complexes containing two monodentate phosphane ligands, respectively. Surprisingly, (2) spontaneously forms an acentric structure, suggesting it might be a potential second-order NLO material. The crystal structure of complex (3) is composed of two parts, namely a [Zn(dppmO2)3]2+cation [dppmO2is bis(diphenylphosphoryl)methane] and a [ZnI4]2−anion. The UV–Vis absorption spectra, thermal stabilities and photoluminescence spectra of the title complexes have also been studied. Time-dependent density functional theory (TD–DFT) calculations reveal that the low-energy UV absorption and the corresponding light emission both result from halide-ligand charge-transfer (XLCT) excited states.

Investigation of charge transfer complexes formed between (S, S)-bis-N,N-sulfonyl bis-L-phenylalanine dimethylester donor with tetracyanoethylene and chloranil as π-acceptors: Experimental and DFT studies

2016 ◽  
Vol 15 (01) ◽  
pp. 1650009 ◽  
Author(s):  
Messaouda Mohamdi ◽  
Nadjia Bensouilah ◽  
Mohamed Abdaoui
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Population Analysis ◽  
Electronic Spectroscopy ◽  
Experimental Studies ◽  
Spectrophotometric Titration ◽  
Charge Transfer Complexes ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Td Dft

Two novel charge transfer complexes CTC ([D[Formula: see text]TCNE] and [D[Formula: see text]CHL] : D [Formula: see text] (S, S)-bis-N,N-sulfonyl bis-L-phenylalanine dimethylester; TCNE [Formula: see text] Tetracyanoethylene; CHL [Formula: see text] Chloranil) were synthesized and characterized by elemental analysis: Electronic absorption, spectrophotometric titration, IR. The obtained results indicate the formation of 1:1 for both complexes. The experimental studies were complemented by quantum chemical calculations at DFT/CAM-B3LYP level of theory. Optimized geometrical structures, the electronic spectroscopy, excited-state properties and the descriptions of frontier molecular orbitals were computed and discussed by time-dependent density functional theory (TD-DFT). In addition, vibrational frequency calculations, the natural population analysis (NPA) confirms the presence of intermolecular interactions and natural bonding orbitals (NBO) calculation was carried out in order to elucidate the interactions between TCNE [Formula: see text]-acceptor and donor molecule.

Electronically excited states of cob(ii)alamin: insights from CASSCF/XMCQDPT2 and TD-DFT calculations

2016 ◽  
Vol 18 (6) ◽  
pp. 4513-4526 ◽  
Author(s):  
Brady D. Garabato ◽  
Neeraj Kumar ◽  
Piotr Lodowski ◽  
Maria Jaworska ◽  
Pawel M. Kozlowski
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Electronically Excited States ◽  
Td Dft ◽  
Electronically Excited ◽  
Dependent Density

The low-lying excited states of cob(ii)alamin were investigated using time-dependent density functional theory (TD-DFT), and multiconfigurational CASSCF/XMCQDPT2 methodology, to help understand their role in B12-mediated reactions.

The hydrolysis mechanism of polyglycolic acid under tensile mechanical loading: a density functional theory study

RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 35862-35867 ◽  
Author(s):  
Shin-Pon Ju ◽  
Wei-Chun Huang ◽  
Chien-Chia Chen
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Mechanical Loading ◽  
Density Functional ◽  
Experimental Studies ◽  
Polyglycolic Acid ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Hydrolysis Mechanism ◽  
The Density Functional Theory

The hydrolysis mechanisms of polyglycolic acid (PGA) under tensile mechanical loading were studied by the density functional theory (DFT) calculations for illustrating the enhancement of PGA hydrolysis by external mechanical loading found in previous experimental studies (Iran. Polym. J., 2008, 17(9), 691–701).

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