scholarly journals Analysis of Biphenylene and Benzo{3,4}cyclobuta{1,2-c}thiophene Molecular Orbital Structure using the Huckel Method

2021 ◽  
Vol 72 (3) ◽  
pp. 198-209
Author(s):  
Yunita Anggraini ◽  
Inge Magdalena Sutjahja
Keyword(s):  
Molecular Orbital ◽  
Energy Gap ◽  
Energy Levels ◽  
Thiophene Ring ◽  
Resonance Energy ◽  
Electron Population ◽  
Hückel Method ◽  
Gap Resonance ◽  
Advanced Computing ◽  
Computing Method

The Huckel method is an old fashion method to predict the molecular orbital and energies of  electrons in a conjugated molecule. Although Huckel`s theory`s approximations are relatively crude, its general results are still reasonable compared to the advanced computing method and experimental results for many molecules. This paper describes the Huckel calculation of biphenylene and benzo{3,4}cyclobuta{1,2-c}thiophene using the HuLis software. The benzo{3,4}cyclobuta{1,2-c}thiophene is a derivative of biphenylene, in which case one of the benzene rings is replaced by a thiophene ring. This change produces new electronic properties that are interesting to study. This work focused on calculating those molecules on energy levels diagrams, linear combination coefficient of molecular orbitals, molecular orbital shape, energy gap, resonance energy, bond-order, bond length, and charge distribution (π electron population). Besides, we calculate the harmonic oscillator measure of aromaticity (HOMA) parameter to study the Huckel method`s validity.

scholarly journals Detailed analytical studies of 1,2,4-triazole derivatized quinoline

2019 ◽  
Vol 10 (4) ◽  
pp. 281-294 ◽  
Author(s):  
Shilpa Mallappa Somagond ◽  
Manjunath Ningappa Wari ◽  
Saba Kauser Jaweed Shaikh ◽  
Sanjeev Ramchandra Inamdar ◽  
Madan Kumar Shankar ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Active Sites ◽  
Density Functional ◽  
Energy Gap ◽  
Energy Levels ◽  
Visual Image ◽  
Monoclinic Space Group ◽  
Charge Delocalization ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The present study describes, the X-ray single crystal analysis of 4-((2-chloro-6-methoxyquinolin-3-yl)methyl)-2-phenyl-2H-1,2,4-triazol-3(4H)-one (TMQ). The crystal data for C19H15ClN4O2: monoclinic, space group P21/n (no. 14), a = 7.3314(15) Å, b = 12.459(3) Å, c = 18.948(4) Å, β = 98.322(9)°, V = 1712.5(6) Å3, Z = 4, T = 296.15 K, μ(MoKα) = 0.245 mm-1, Dcalc = 1.423 g/cm3, 5082 reflections measured (3.926° ≤ 2Θ ≤ 38.556°), 1428 unique (Rint = 0.0545, Rsigma = 0.0574) which were used in all calculations. The final R1 was 0.0423 (I >2σ(I)) and wR2 was 0.1145 (all data). The Density functional theory optimized molecular geometries in TMQ agree closely with those obtained from crystallographic studies. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energy levels and energy gap were calculated by experimental (UV absorption & Cyclic voltammetry) and theoretical studies in two different solvents. The natural bond orbital analysis was performed to understand the molecular interaction on the basis of stability of molecule arising from hyper-conjugative interaction and charge delocalization. Hirshfeld surface and their related fingerprint plots enabled the identification of significant intermolecular interaction. The molecular electrostatic potential analysis provides the visual image of the chemically active sites and comparable reaction of atoms.

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.

Porphyrin doping of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex for electroluminescence

2013 ◽  
Vol 17 (05) ◽  
pp. 351-358 ◽  
Author(s):  
Mohammad Janghouri ◽  
Ezeddin Mohajerani ◽  
Mostafa M. Amini ◽  
Naser Safari
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Energy Levels ◽  
Orbital Energy ◽  
Homogeneous Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Fundamental Structure ◽  
Organic Light

A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex ( Q2SnCl2 , Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/ Q2SnCl2/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q2SnCl2 is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP): Q2SnCl2 (75nm)/ Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.

scholarly journals A Study of Interfacial Electronic Structure at the CuPc/CsPbI2Br Interface

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 547
Author(s):  
Zengguang Tang ◽  
Liujiang Zhang ◽  
Zhenhuang Su ◽  
Zhen Wang ◽  
Li Chen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Energy Gap ◽  
Hole Transport ◽  
Hole Injection ◽  
Band Bending ◽  
Valance Band Maximum ◽  
Interfacial Electronic Structure

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.

scholarly journals Emphasizing the Operational Role of a Novel Graphene-Based Ink into High Performance Ternary Organic Solar Cells

2019 ◽  
Author(s):  
Minas M. Stylianakis ◽  
Dimitriοs M. Kosmidis ◽  
Katerina Anagnostou ◽  
Christos Polyzoidis ◽  
Miron Krassas ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Organic Solar Cells ◽  
High Performance ◽  
Energy Levels ◽  
Fullerene Derivative ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Synthetic Routes

A novel solution-processed graphene-based material was synthesized by treating graphene oxide (GO) with 2,5,7-trinitro-9-oxo-fluorenone-4-carboxylic acid (TNF-COOH) moieties, via simple synthetic routes. The yielded molecule N-[(carbamoyl-GO)ethyl]-N’-[(carbamoyl)-(2,5,7-trinitro-9-oxo-fluorene)] (GO-TNF) was thoroughly characterized and it was shown that it presents favorable highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels to function as a bridge component between the polymeric donor poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl}) (PTB7) and the fullerene derivative acceptor [6,6]-phenyl-C71-butyric-acid-methylester (PC71BM). In this context, a GO-TNF based ink was prepared and directly incorporated within the binary photoactive layer, in different volume ratios (1-3% ratio to the blend), for the effective realization of inverted ternary organic solar cells (OSCs) of the structure ITO/PFN/PTB7:GO-TNF:PC71BM/MoO3/Al. The addition of 2% v/v GO-TNF ink led to a champion power conversion efficiency (PCE) of 8.71% that was enhanced by ~13% as compared to the reference cell.

R-matrix calculations of photoionization cross section of Ne-like tungsten

2015 ◽  
Vol 93 (11) ◽  
pp. 1221-1226 ◽  
Author(s):  
Indu Khatri ◽  
Arun Goyal ◽  
Sunny Aggarwal ◽  
A.K. Singh ◽  
Man Mohan
Keyword(s):  
Cross Section ◽  
Energy Levels ◽  
Resonance Energy ◽  
Photoionization Cross Section ◽  
Distorted Wave ◽  
Rydberg Series ◽  
Close Coupling ◽  
R Matrix ◽  
Coupling Approximation ◽  
Wave Methods

The photoionization cross section calculation for the ground state 1s22s22p6 1S (J = 0) of Ne-like W64+ has been performed in the close-coupling approximation using the Dirac–Coulomb R-matrix method. The resonance structures are analysed and described by finding the resonance energy positions of prominent Rydberg series 2s2p6(2S)np 1P0 for W LXV ion. To calculate fine structure energy levels, multi-configuration Dirac–Fock and relativistic distorted-wave methods have been employed. Wherever possible we have compared our work with the available data. The present results will be useful for diagnostics and modeling of plasma in ITER and other fusion devices.

scholarly journals Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

2017 ◽  
Vol 13 ◽  
pp. 863-873 ◽  
Author(s):  
Vinila N Viswanathan ◽  
Arun D Rao ◽  
Upendra K Pandey ◽  
Arul Varman Kesavan ◽  
Praveen C Ramamurthy
Keyword(s):  
Molecular Orbital ◽  
Architectural Design ◽  
Density Functional ◽  
Short Circuit ◽  
Energy Levels ◽  
Photovoltaic Performance ◽  
Hole Mobility ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Lowest Unoccupied Molecular Orbital

A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at −5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3.

DFT STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ENDOHEDRAL COMPLEXES OF GROUP V ATOMS WITH C60

2013 ◽  
Vol 27 (26) ◽  
pp. 1350152 ◽  
Author(s):  
AKSHU PAHUJA ◽  
SUNITA SRIVASTAVA
Keyword(s):  
Electronic Properties ◽  
Energy Gap ◽  
Central Atom ◽  
Energy Levels ◽  
Electronic Configuration ◽  
Group V ◽  
Foreign Atom ◽  
Endohedral Fullerenes ◽  
Endohedral Complexes ◽  
Structural And Electronic Properties

The structural and electronic properties of endohedral fullerenes formed by encapsulation of each of the group V elements inside the buckminsterfullerene cage have been investigated. The calculations reveal that all these species are thermodynamically stable, though the formation of Sb@C 60 and Bi@C 60 is slightly endothermic. The central atom preserves its electronic configuration and the quartet state. The energy gap and energy levels are perturbed by the inclusion of a foreign atom. The band gap of Sb@C 60 and Bi@C 60 is found to be significantly smaller than pristine C 60, suggesting the reactivity of these complexes.

Computational Study on Triphenylamine-Based Dyes Containing Benzimidazole Units for Dye-Sensitized Solar Cells

2013 ◽  
Vol 668 ◽  
pp. 110-114
Author(s):  
Zhong Quan Wan ◽  
Lin Lei Zhou ◽  
Chun Yang Jia ◽  
Xiao Jun Yao ◽  
Yu Shi
Keyword(s):  
Absorption Spectra ◽  
Molecular Orbital ◽  
High Efficiency ◽  
Computational Study ◽  
Electronic Absorption Spectra ◽  
Energy Levels ◽  
Dye Sensitized Solar Cells ◽  
Conduction Band Edge ◽  
Tio2 Electrode ◽  
Lowest Unoccupied Molecular Orbital

Three novel dyes (D1, D2 and D3) containing triphenylamine (TPA) unit as core and bearing different benzimidazole units as secondary electron-donors are designed. The geometries, electronic structures, and electronic absorption spectra of these dyes are studied by DFT and TD-DFT. The optimized results indicate that these dyes are all non-coplanar, which can help to inhibit the close intermolecular π-π stacking aggregation effectively. The lowest unoccupied molecular orbital (LUMO) energy levels of the dyes are higher than the conduction band edge of the TiO2, which ensures a high efficiency of electron transfer from these dyes to TiO2 electrode. As the highest occupied molecular orbital (HOMO) energy levels of these dyes are lower than those of I-/I-3, these molecules that lose electrons could be restored by getting electrons from electrolyte. The absorption spectra of these dyes are simulated, and the calculated results indicate that D3 can absorb more photons than those of D1, D2 and TPAR in the region from 250 to 580 nm, which should have the best performance of photo-to-electric conversion efficiency.

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