scholarly journals Synthesis, Photophysical, Electrochemical, and DFT Examinations of Two New Organic Dye Molecules Based on Phenothiazine and Dibenzofuran

2021 ◽  
Author(s):  
Periyasamy Kannan ◽  
Sakthivel P ◽  
Venkatesh G ◽  
Anbarasan PM ◽  
Vennila P ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Orbital Energy ◽  
Electronic Excitations ◽  
Dye Molecules ◽  
Oxidation Potentials ◽  
Absorption Performance ◽  
Ft Ir ◽  
Photovoltaic Characteristics

Abstract New dyes were developed and produced utilizing distinct electron donors (phenothiazine and dibenzofuran), a p-spacer, and an electron acceptor of cyanoacetohydrazide, and their structures were studied using FT-IR and NMR spectroscopy. Following the synthesis of dye molecules, the photophysical and photovoltaic characteristics were investigated using experimental and theoretical methods. The photosensitizers have been exposed to electrochemical and optical property experiments in order to study their absorption performance and also molecular orbital energies. The monochromatic optical conversion efficiency of (Z)-N-((5-(10H-phenothiazin-2-yl)furan-2-yl)methylene)-2-cyanoacetohydrazide (PFCH) found higher than that of (Z)-2-cyano-N'-((5-(dibenzo[b,d]furan-4-yl)furan-2-yl)methylene)acetohydrazide (BFCH), with IPCEs of 58 and 64% for BFCH and PFCH, respectively. According to the photosensitizer molecular energy level diagram, the studied dye molecules have strong thermodynamically advantageous ground and excited state oxidation potentials for electron injection into the conduction band of titanium oxide. It was observed that the ability to attract electrons correlated favorably with molecular orbital energy. While density functional theory calculations were used to examine molecule geometries, vertical electronic excitations, and frontier molecular orbitals, experimental and computed results were consistent. Natural bond orbital and nonlinear optical properties were also calculated and discussed.

On the Nature of Halide-Water Interactions: Insights from Many-Body Representations and Density Functional Theory

2019 ◽  
Author(s):  
Brandon B. Bizzarro ◽  
Colin K. Egan ◽  
Francesco Paesani
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Molecular Orbital ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Orbital Energy ◽  
Energy Decomposition Analysis ◽  
Interaction Energies ◽  
Many Body ◽  
Functional Theory

<div> <div> <div> <p>Interaction energies of halide-water dimers, X<sup>-</sup>(H<sub>2</sub>O), and trimers, X<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub>, with X = F, Cl, Br, and I, are investigated using various many-body models and exchange-correlation functionals selected across the hierarchy of density functional theory (DFT) approximations. Analysis of the results obtained with the many-body models demonstrates the need to capture important short-range interactions in the regime of large inter-molecular orbital overlap, such as charge transfer and charge penetration. Failure to reproduce these effects can lead to large deviations relative to reference data calculated at the coupled cluster level of theory. Decompositions of interaction energies carried out with the absolutely localized molecular orbital energy decomposition analysis (ALMO-EDA) method demonstrate that permanent and inductive electrostatic energies are accurately reproduced by all classes of XC functionals (from generalized gradient corrected (GGA) to hybrid and range-separated functionals), while significant variance is found for charge transfer energies predicted by different XC functionals. Since GGA and hybrid XC functionals predict the most and least attractive charge transfer energies, respectively, the large variance is likely due to the delocalization error. In this scenario, the hybrid XC functionals are then expected to provide the most accurate charge transfer energies. The sum of Pauli repulsion and dispersion energies are the most varied among the XC functionals, but it is found that a correspondence between the interaction energy and the ALMO EDA total frozen energy may be used to determine accurate estimates for these contributions. </p> </div> </div> </div>

scholarly journals A novel selective fluorescent chemosensor for Fe3+ ions based on phthalonitrile dimer: synthesis, analysis, and theoretical studies

2020 ◽  
Vol 44 (5) ◽  
pp. 1254-1264
Author(s):  
Shaya AL-RAQA ◽  
İpek ÖMEROĞLU ◽  
Doğan ERBAHAR ◽  
Mahmut DURMUŞ
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Interaction Mechanism ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Density Functional Theory Calculations ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Cross Coupling Reaction ◽  
Ft Ir

Phenyl-4,4-di(3,6-dibutoxyphthalonitrile) (3) was synthesized by the reaction of 1,4-phenylenebisboronic acid (1) and 4-bromo-3,6-dibutoxyphthalonitrile (2), using Suzuki cross-coupling reaction. The newly synthesized compound (3) was characterized by FT-IR, MALDI-MS, ESI-MS, 1H-NMR, 13C-NMR, and 13C-DEPT-135-NMR. The fluorescence property of phenyl-4,4-di(3,6- dibutoxyphthalonitrile) (3) towards various metal ions was investigated by fluorescence spectroscopy, and it was observed thatthe compound (3) displayed a significantly ‘turn-off’ response to Fe3+, which was referred to 1:2 complex formation between ligand (3) and Fe3+. The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe3+ ions.

Orbital-based Descriptions of Electron Configurations, Ionization, Excitation, and Bonding

2020 ◽  
pp. 188-216
Author(s):  
Jochen Autschbach
Keyword(s):  
Molecular Orbital ◽  
Ground State ◽  
Orbital Energy ◽  
Chemical Bonds ◽  
Theory Construction ◽  
Electronic Excitations ◽  
Energy Gaps ◽  
Koopmans Theorem ◽  
Total Energies ◽  
Ground State Electron

This chapter deals with quantitative aspects of molecular orbital (MO) theory: Construction of an orbital diagram, bonding and antibonding overlap, Koopmans’ theorem, orbital energies versus total energies, an explanation of the unintuitive ground state electron configurations seen for some neutral transition metals, and a discussion of orbital energy gaps versus electronic excitations and other observable energy gaps. Localized MOs show the chemical bonds expected from the Lewis structure more readily than the canonical orbitals obtained from solving the SCF equations. It is shown that the delocalization of localized, not the canonical, MOs shows whether a system is delocalized. Algorithms by which to obtain localized MOs are sketched.

AB INITIO AND DFT THEORETICAL INVESTIGATIONS ON NOVEL PORPHYRIN–FULLERENE SUPRAMOLECULAR DYADS FOR PHOTOVOLTAIC DEVICES

2008 ◽  
Vol 07 (05) ◽  
pp. 1055-1069 ◽  
Author(s):  
TAPAS MANNA ◽  
SUMANTA BHATTACHARYA
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Density Functional ◽  
Conformational Stability ◽  
Density Functional Theory Calculations ◽  
Orbital State ◽  
Highest Occupied Molecular Orbital ◽  
Theoretical Investigations ◽  
Lowest Unoccupied Molecular Orbital ◽  
Porphyrin Moiety

The conformational stability and electronic structures of novel H 2-(1) and Zn-tetraphenylporphyrin–[60]fullerene (2) dyads, in which the [60]fullerene is directly linked to the tetrapyrrolic rings by ethynylenephenylene subunits, have been studied by ab initio and density functional theory calculations. From the investigation on frontier molecular orbitals, it was found that the lowest unoccupied molecular orbital state of these supramolecules is localized on the fullerene and that the highest occupied molecular orbital state is localized on the porphyrin moiety. Molecular electrostatic potential maps clearly demonstrate the electron transfer phenomena from the porphyrin moiety to the fullerene in dyads 1 and 2.

scholarly journals Mechanosynthesis of Photochromic Oligophenyleneimines: Optical, Electrochemical and Theoretical Studies

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 849 ◽  
Author(s):  
Miguel Amado-Briseño ◽  
Luis Zárate-Hernández ◽  
Karina Alemán-Ayala ◽  
Oscar Coreño Alonso ◽  
Julián Cruz-Borbolla ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Chloroform Solution ◽  
Photochromic Properties ◽  
Highest Occupied Molecular Orbital ◽  
Vis Spectroscopy ◽  
Structural And Electronic Properties ◽  
Lowest Unoccupied Molecular Orbital ◽  
Ft Ir

In this work, two oligophenyleneimines type pentamers with terminal aldehydes, designated as DAFCHO (4,4′-((((((2,5-bis(octyloxy)-1,4-phenylene)bis(methanylylidene))bis(azanyl ylidene))bis(9H-fluorene-7,2-diyl))bis(azanylylidene))bis(methanylylidene))bis(2,5-bis(octyloxy) benzaldehyde)) and FDACHO (4,4′-((((((2,5-bis(octyloxy)-1,4-phenylene)bis(methanylylidene))bis (azanylylidene))bis(4,1-phenylene))bis(azanylylidene))bis(methanylylidene))bis(2,5-bis(octyloxy) benzaldehyde)) were synthesized by mechanochemistry method using 2,5-bis(octyloxy) terephtal aldehyde and 2,7-diaminofluorene or 1,4-phenylenediamine. All compounds were spectroscopically characterized using 1H and 13C-NMR, FT-IR and mass spectrometry MALDITOF. The optical properties of the compounds were analyzed by UV-vis spectroscopy using different solvents. We observed that DAFCHO and FDACHO exhibit interesting photochromic properties when they are dissolved in chloroform and exposed to sunlight for 3, 5 and 10 min. The value of the energy band gap was calculated from the absorption spectra without irradiation Egap(optical). It was 2.50 eV for DAFCHO in chloroform solution, and it decreased to 2.34 eV when it is in films. For FDACHO, it was 2.41 eV in solution and 2.27 eV in film. HOMO (Highest Occupied Molecular Orbital), LUMO (Lowest Unoccupied Molecular Orbital) and Egap(electrochemical) values were obtained by electrochemical studies. The results indicate that the compounds can be considered as organic semiconductors since their values are 2.35 eV for DAFCHO and 2.06 eV for FDACHO. The structural and electronic properties of the compounds were corroborated with a DFT (Density Functional Theory) study.

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