scholarly journals DFT and TD-DFT Study of Only First Diaminomalenonitrile Based Molecular Receptor for Fluoride Anion: Correlation of Calculated and Experimental Results

2021 ◽  
Vol 13 (3) ◽  
pp. 923-933
Author(s):  
M. A. Kaloo ◽  
H. Bashir ◽  
M. A. Rather ◽  
S. A. Majid ◽  
B. A. Bhat
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Atomic Orbital ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Fluoride Anion ◽  
Functional Theory ◽  
Sensing Mechanism ◽  
Td Dft

In this work, the sensing mechanism of a novel anion receptor, 2-amino-((E)-(4-cyanobenzalidine) amino) maleonitrile reported by Sankar et al. (Analyst 138:4760-4763, 2013) was investigated theoretically with the help of density functional theory (DFT) and time-dependent density functional theory (TD-DFT). From the frontier molecular orbital analysis, it is reasonable to support the proposed charge transfer (ICT) enhancement in the receptor molecule in the presence of F−. A significant reduction in the energy gap (ΔE) from 4.014 eV to 2.342eV between highest occupied and lowest unoccupied energy levels was revealed, leading to the strong redshift of its absorption characteristics. Moreover, 1H NMR was also calculated to further understand the mechanistic insights by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G (d,p) basis set. The spectra were simulated, and the chemical shifts linked to TMS were compared with experimental. Besides, Intrinsic Reaction Coordinates (IRC) were also calculated to understand the sensing mechanism.

scholarly journals X-ray diffraction and Density Functional Theory based structural analyses of 2-phenyl-4-(prop-2-yn-1-yl)-1,2,4-triazolone

2021 ◽  
Vol 12 (4) ◽  
pp. 459-468
Author(s):  
Shilpa Mallappa Somagond ◽  
Ahmedraza Mavazzan ◽  
Suresh Fakkirappa Madar ◽  
Madivalagouda Sannaikar ◽  
Shankar Madan Kumar ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Geometrical Parameters ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

This study is composed of X-ray diffraction and Density Functional Theory (DFT) based molecular structural analyses of 2-phenyl-4-(prop-2-yn-1-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2PPT). Crystal data for C11H9N3O: Monoclinic, space group P21/c (no. 14), a = 7.8975(2) Å, b = 11.6546(4) Å, c = 11.0648(3) Å, β = 105.212(2)°, V = 982.74(5) Å3, Z = 4, T = 296.15 K, μ(MoKα) = 0.091 mm-1, Dcalc = 1.346 g/cm3, 13460 reflections measured (5.174° ≤ 2Θ ≤ 64.72°), 3477 unique (Rint = 0.0314, Rsigma = 0.0298) which were used in all calculations. The final R1 was 0.0470 (I > 2σ(I)) and wR2 was 0.1368 (all data). The experimentally determined data was supported by theoretically optimized calculations processed with the help of Hartree-Fock (HF) technique and Density Functional Theory with the 6-311G(d,p) basis set in the ground state. Geometrical parameters (Bond lengths and angles) as well as spectroscopic (FT-IR, 1H NMR, and 13C NMR) properties of 2PPT molecule has been optimized theoretically and compared with the experimentally obtained results. Hirshfeld surface analysis with 2D fingerprinting plots was used to figure out the possible and most significant intermolecular interactions. The electronic characterizations such as molecular electrostatic potential map (MEP) and Frontier molecular orbital (FMO) energies have been studied by DFT/B3LYP approach. The MEP imparted the detailed information regarding electronegative and electropositive regions across the molecule. The HOMO-LUMO energy gap as high as 5.3601 eV was found to be responsible for the high kinetic stability of the 2PPT.

scholarly journals Structural, Electronic, Molecular Orbital Analysis and Charge Distributions on Nitrate Salt of Guanidine through DFT and TD-DFT Methods

2021 ◽  
Vol 33 (8) ◽  
pp. 1905-1910
Author(s):  
S. Thangarasu ◽  
V. Siva ◽  
A. Shameem ◽  
A. Murugan ◽  
S. Athimoolam ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Ion Pairs ◽  
Frontier Molecular Orbital ◽  
Mulliken Charge ◽  
Functional Theory ◽  
Td Dft ◽  
Guanidinium Nitrate

Guanidinium nitrate, a non-linear optical material has been systematically studied through quantum chemical (density functional theory and Hartree Fock) methods. Studies on Mulliken charge, Frontier molecular orbitals (FMOs) and hyperpolarizability analyses have been performed. The Mulliken population analyses were carried out for the optimized molecular geometry by HF and B3LYP methods with 6-311++G(d,p) levels. The molecular orbital parameters of guanidinium nitrate have been calculated by FMO analysis. Frontier molecular orbital (FMO) analysis indicates the electron delocalization on the guanidinium nitrate and also its low value of energy gap indicates electron transfer. Optical property has been investigated by time-dependent density functional theory (TD-DFT) calculation. The second-order hyperpolarizability value of the ion pairs is much greater than urea, which confirms the good NLO nature of guanidinium nitrate.

scholarly journals Structural and spectroscopic characterization and DFT studies of 2-amino-1,10-phenanthrolin-1-ium chloride

2019 ◽  
Vol 10 (2) ◽  
pp. 95-101
Author(s):  
Sebile Işık Büyükekşi ◽  
Namık Özdemir ◽  
Abdurrahman Şengül
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
13C Nmr ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Basis Set ◽  
Functional Theory ◽  
1H And 13C Nmr

A versatile synthetic building block, 2-amino-1,10-phenanthrolin-1-ium chloride (L∙HCl) was synthesized and characterized by IR, 1H and 13C NMR DEPT analysis, UV/Vis and single-crystal X-ray diffraction technique. The molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO), 1H and 13C NMR chemical shifts values of the title compound in the ground state were obtained by using density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set and compared with the experimental data. Electronic absorption spectrum of the salt was determined using the time-dependent density functional theory (TD-DFT) method at the same level. In the NMR and electronic absorption spectra calculations, the effect of solvent on the theoretical parameters was included using the default model with DMSO as solvent. The obtained theoretical parameters agree well with the experimental findings.

Donor Functionalized Perylene and Different π-Spacers Based Sensitizers for DSSC Applications - A Theoretical Approach

2021 ◽  
Author(s):  
D. Nicksonsebastin ◽  
P. Pounraj ◽  
Prasath M
Keyword(s):  
Density Functional Theory ◽  
Solar Cell ◽  
Gas Phase ◽  
Density Functional ◽  
Basis Set ◽  
Dye Sensitized Solar Cell ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Organic Sensitizers

Abstract Perylene based novel organic sensitizers for the Dye sensitized solar cell applications are investigated by using Density functional theory (DFT) and time dependant density functional theory (TD-DFT).The designed sensitizers have perylene and dimethylamine (DM) and N-N-dimethylaniline(DMA) functionalized perylene for the dssc applications.π-spacers are thiophene andcyanovinyl groups and cyanoacrylic acid is chosen as the acceptor for the designed sensitizers. The studied sensitizers were fully optimized by density functional theory at B3LYP/6-311G basis set on gas phase and DMF phase. The electronic absorption of the sensitizers is analyzed by TD-DFT at B3LYP/6-311G basis set in both gas and DMF phase.

SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE AND NON-LINEAR OPTICAL PROPERTIES OF PYRENE AND SOME OF ITS DERIVATIVES BASED ON DENSITY FUNCTIONAL THEORY

2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Lumo Energy ◽  
Functional Theory ◽  
Organic Optoelectronic ◽  
Homo Lumo

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was  used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene  in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of  and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents.  In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.

scholarly journals 1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
Dawid Zych
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Basis Set ◽  
Functional Theory ◽  
Td Dft ◽  
Pyrene Derivatives ◽  
Osmium Complexes ◽  
The Subject ◽  
Theoretical Considerations

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established.

Density Functional Theory Based Modeling of the Corrosion on Iron Surfaces

2013 ◽  
Vol 58 (2) ◽  
pp. 321-323 ◽  
Author(s):  
N. Nunomura ◽  
S. Sunada
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Atomic Orbital ◽  
Atomic Layer ◽  
Iron Surface ◽  
Basis Set ◽  
Water Molecules ◽  
Aqueous Corrosion ◽  
Functional Theory ◽  
Adsorption Of Water

In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.

scholarly journals Theoretical Study of a Class of Organic D-π-A Dyes for Polymer Solar Cells: Influence of Various π-Spacers

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 163
Author(s):  
Nguyen Van Trang ◽  
Tran Ngoc Dung ◽  
Ngo Tuan Cuong ◽  
Le Thi Hong Hai ◽  
Daniel Escudero ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Polymer Solar Cells ◽  
Basis Set ◽  
Structure Theory ◽  
Functional Theory ◽  
Alkyl Groups

A class of D-π-A compounds that can be used as dyes for applications in polymer solar cells has theoretically been designed and studied, on the basis of the dyes recently shown by experiment to have the highest power conversion efficiency (PCE), namely the poly[4,8-bis(5-(2-butylhexylthio)thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl-alt-TZNT] (PBDTS-TZNT) and poly[4,8-bis(4-fluoro-5-(2-butylhexylthio)thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl-alt-TZNT] (PBDTSF-TZNT) substances. Electronic structure theory computations were carried out with density functional theory and time-dependent density functional theory methods in conjunction with the 6−311G (d, p) basis set. The PBDTS donor and the TZNT (naphtho[1,2-c:5,6-c]bis(2-octyl-[1,2,3]triazole)) acceptor components were established from the original substances upon replacement of long alkyl groups within the thiophene and azole rings with methyl groups. In particular, the effects of several π-spacers were investigated. The calculated results confirmed that dithieno[3,2-b:2′,3′-d] silole (DTS) acts as an excellent π-linker, even better than the thiophene bridge in the original substances in terms of well-known criteria. Indeed, a PBDTS-DTS-TZNT combination forms a D-π-A substance that has a flatter structure, more rigidity in going from the neutral to the cationic form, and a better conjugation than the original compounds. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap of such a D-π-A substance becomes smaller and its absorption spectrum is more intense and red-shifted, which enhances the intramolecular charge transfer and makes it a promising candidate to attain higher PCEs.

scholarly journals DFT and TD-DFT Study of Structure and Properties of Semiconductive Hybrid Networks Formed by Bismuth Halides and Different Polycyclic Aromatic Ligands

2011 ◽  
Vol 8 (s1) ◽  
pp. S195-S202
Author(s):  
Y. Belhocine ◽  
M. Bencharif
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Relativistic Effects ◽  
Spectroscopic Properties ◽  
Basis Set ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
Polycyclic Aromatic

The structure and spectroscopic properties of polycyclic aromatic ligands of 2,3,6,7,10,11-hexakis (alkylthio) triphenylene (alkyl: methyl, ethyl, and isopropyl; corresponding to the abbreviations of the molecules: HMTT, HETT and HiPTT) were studied using density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods with triple-zeta valence polarization (TZVP) basis set. It was shown that the type of functional theory used, Becke-Perdew (BP) and Leeuwen-Baerends (LB94) implemented in Amsterdam Density functional (ADF) program package, does not have essential influence on the geometry of studied compounds in both ground and excited states. However, significant differences were obtained for the band gap values with relativistic effects of the zero order regular approximation scalar corrections (ZORA) and LB94 functional seems to reproduce better the experimental optical band gap of these systems.

scholarly journals Molecular engineering of indenoindene-3-ethylrodanine acceptors with A2-A1-D-A1-A2 architecture for promising fullerene-free organic solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Khalid ◽  
Momina ◽  
Muhammad Imran ◽  
Muhammad Fayyaz ur Rehman ◽  
Ataualpa Albert Carmo Braga ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Charge Transfer ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Energy Gap ◽  
Molecular Engineering ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Acceptor Molecules

AbstractConsidering the increased demand and potential of photovoltaic devices in clean, renewable electrical and hi-tech applications, non-fullerene acceptor (NFA) chromophores have gained significant attention. Herein, six novel NFA molecules IBRD1–IBRD6 have been designed by structural modification of the terminal moieties from experimentally synthesized A2-A1-D-A1-A2 architecture IBR for better integration in organic solar cells (OSCs). To exploit the electronic, photophysical and photovoltaic behavior, density functional theory/time dependent-density functional theory (DFT/TD-DFT) computations were performed at M06/6-311G(d,p) functional. The geometry, electrical and optical properties of the designed acceptor molecules were compared with reported IBR architecture. Interestingly, a reduction in bandgap (2.528–2.126 eV), with a broader absorption spectrum, was studied in IBR derivatives (2.734 eV). Additionally, frontier molecular orbital findings revealed an excellent transfer of charge from donor to terminal acceptors and the central indenoindene-core was considered responsible for the charge transfer. Among all the chromophores, IBRD3 manifested the lowest energy gap (2.126 eV) with higher λmax at 734 and 745 nm in gaseous phase and solvent (chloroform), respectively due to the strong electron-withdrawing effect of five end-capped cyano groups present on the terminal acceptor. The transition density matrix map revealed an excellent charge transfer from donor to terminal acceptors. Further, to investigate the charge transfer and open-circuit voltage (Voc), PBDBT donor polymer was blended with acceptor chromophores, and a significant Voc (0.696–1.854 V) was observed. Intriguingly, all compounds exhibited lower reorganization and binding energy with a higher exciton dissociation in an excited state. This investigation indicates that these designed chromophores can serve as excellent electron acceptor molecules in organic solar cells (OSCs) that make them attractive candidates for the development of scalable and inexpensive optoelectronic devices.

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