scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

A high-pressure study of HfC and nano-crystalline TiC by X-ray diffraction and density functional theory calculations

2020 ◽  
Vol 34 (34) ◽  
pp. 2050393
Author(s):  
Lun Xiong ◽  
Bin Li ◽  
Bi Liang ◽  
Jinxia Zhu ◽  
Hong Yi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Nano Crystalline

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus [Formula: see text] GPa with [Formula: see text] of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is [Formula: see text] GPa with [Formula: see text].

Experimental and DFT computational studies of L-alanine cadmium chloride crystals

2016 ◽  
Vol 05 (01) ◽  
pp. 1630001
Author(s):  
I. Cicili Ignatius ◽  
S. Dheivamalar ◽  
K. Kirubavathi ◽  
K. Selvaraju
Keyword(s):  
Cadmium Chloride ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Functional Theory ◽  
Bond Angles ◽  
Cell Parameters ◽  
B3lyp Calculation

In this work, we report the combined experimental and theoretical study on molecular structure and vibrational spectra of nonlinear optical crystal L-alanine cadmium chloride (LACC). The single X-ray diffraction studies have revealed that the compound crystallizes in monoclinic system C2 space group with cell parameters [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. FTIR and Raman spectra of the nonlinear optical materials LACC have been recorded and analyzed. The optimized geometric bond length and bond angles are obtained with the help of density functional theory (DFT) (B3LYP) calculation. The optimized geometric bond lengths and bond angles obtained by using DFT show good agreement with the experimental data. Using the natural bond orbital analysis the electronic effect and hydrogen bonding were confirmed. The HOMO–LUMO energy gap and the first order hyperpolarizability were calculated and it supports the nonlinear optical activity of LACC crystal.

Theoretical study of 11-thiocyanatoundecanoic acid phenylamide derivatives on corrosion inhibition efficiencies

2014 ◽  
Vol 92 (9) ◽  
pp. 876-887 ◽  
Author(s):  
Seda Sagdinc ◽  
Yesim Kara ◽  
Filiz Kayadibi
Keyword(s):  
Density Functional ◽  
Corrosion Inhibitors ◽  
Energy Gap ◽  
Basis Set ◽  
Inhibitor Molecule ◽  
Functional Theory ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Hartree Fock ◽  
Adsorption Sites

Ab initio Hartree–Fock (HF) and Density Functional Theory (DFT) B3LYP methods with the 6-311G(d,p) basis set were applied to the three 11-thiocyanatoundecanoic acid phenylamide derivatives as corrosion inhibitors. Inhibition efficiency obtained experimentally followed the following order: N-(4-methoxyphenyl)-11-thiocyanatoundecanamide (N3MPTUA) > N-phenyl-11-thiocyanatoundecanamide (NPTUA) > N-(3-nitrophenyl)-11-thiocyanatoundecanamide (N3NPTUA). The molecular parameters most relevant to their potential action as corrosion inhibitors have been calculated in the neutral and protonated forms: EHOMO, ELUMO, energy gap (ΔE), dipole moment (μD), electronegativity (χ), global hardness (η), and the fraction of electrons transferred from the inhibitor molecule to the metallic atom (ΔN). The results of most of the global reactivity descriptors show that the experimental and theoretical studies agree well, and confirm that N3MPTUA is a better inhibitor than NPTUA or N3NPTUA. In addition, the local reactivity, analyzed through Fukui functions, show that the oxygen and nitrogen atoms will be the main adsorption sites.

scholarly journals The Interaction of Adenine with Zn12O12 Cluster from Density Functional Theory

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Nguyen Huu Tho ◽  
Nguyen Thanh Trung
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Population Analysis ◽  
Basis Sets ◽  
Base Interaction ◽  
Functional Theory ◽  
Model Cluster ◽  
Dna Base ◽  
Energy Frontier

Geometries associated energy gap and electronic properties of adenine, DNA base interaction on the ZnO model cluster have been investigated by using density functional theory with the B3LYP exchange-correlation potential and effective core potential (ECP) LanL2DZ basis sets. The most stable interaction characteristics were analysed with respect to the binding energy, frontier orbital, elemental positions. Natural population analysis charge is also examined to understand the associated charge transfer in structures of cluster and complex. In the Zn-N bonding, combination coefficient from atom orbitals of nitrogen is much higher than that of zinc. The corresponding weight for this coefficient is 94.80%. The results of this study can serve as an orientation for the design of composite material in biomedical nanotechnology.

Role of heteroatoms and substituents on the structure, reactivity, aromaticity, and absorption spectra of pyrene: a density functional theory study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bapan Saha ◽  
Pradip Kumar Bhattacharyya
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Density Functional ◽  
Structural Parameters ◽  
Visible Absorption ◽  
Functional Theory ◽  
Solvent Phase ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible

Abstract Effect of heteroatoms viz. BN and substituents viz. –Me (methyl), –OH (hydroxyl), –NH2 (amine), –COOH (carboxyl), and –CN (cyano) on the structural parameters, global reactivity, aromaticity, and UV-visible spectra of pyrene are studied with the help of density functional theory (DFT). Global reactivity parameters such as global hardness (η) and electrophilicity (ω) are calculated using density functional reactivity theory (DFRT). Time dependent density functional theory (TD-DFT) is explored for interpreting the UV-visible absorption spectra. Aromaticity of the pyrene rings are predicted from the nucleus independent chemical shift (NICS) values. Presence of BN unit and substituent induces reasonable impact on the studied parameters. The observed absorption spectra lie predominantly within the UV-region (both blue and red shifts are observed in presence of BN and substituent). HOMO energy and absorption spectra are affected nominally in solvent phase.

Synthesis, optical characterization, and TD-DFT studies of novel mero/bis-mero cyanine dyes based on N-Bridgehead heterocycles

2019 ◽  
Vol 97 (3) ◽  
pp. 219-226
Author(s):  
Ahmed I. Koraiem ◽  
Islam M. Abdellah ◽  
Ahmed El-Shafei ◽  
Fathy F. Abdel-Latif ◽  
Reda M. Abd El-Aal
Keyword(s):  
Excitation Energy ◽  
Density Functional ◽  
Energy Gap ◽  
Solvent Polarity ◽  
Cyanine Dyes ◽  
Spectral Studies ◽  
Functional Theory ◽  
Td Dft ◽  
Homo Lumo ◽  
Good Agreement

Novel mero/bis-mero cyanine dyes based on N-Bridgehead imidazo[1,2-g]quinolino[2,1-a][2,6]naphthyridine have been synthesized and characterized to evaluate intramolecular charge transfer (ICT) effect on the energy gap (E0-0). The UV–vis and emission spectral studies revealed that dyes are absorbed in the region of λmax 485–577 nm and emitted at 567–673 nm. Their solvatochromic behavior in solvents of various polarities, CCl4, C6H6, H2O, CHCl3, acetone, and DMF, was studied to emphasize the effect of solvent polarity on the absorption maxima, molar extinction coefficients of the dyes, and excitation energy of the dyes. Their electron cloud delocalization in HOMO/LUMO levels were studied by DFT using Gaussian 09 software. Time-dependent density functional theory (TD-DFT) was applied to theoretically explore the first excitation energy (E0-0) of these dyes, which was in good agreement with experimental results.

scholarly journals Computational studies of the thermodynamic properties, and global and reactivity descriptors of fluorescein dye derivatives in acetonitrile using density functional theory

2021 ◽  
pp. 174751982199451
Author(s):  
Juma Mzume Juma ◽  
Said AH Vuai
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Ionization Potential ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Sets ◽  
Hybrid Functional ◽  
Functional Theory ◽  
Reactivity Descriptors

This work reports density functional theory calculations of the optimized geometries, molecular reactivity, energy gap, and thermodynamic properties of molecular dyes fluorescein (FS), fluorescein attached with methoxy (FSO), fluorescein attached with amine (FSA), fluorescein attached with methane (FSM), fluorescein attached with ethene (FSE), and fluorescein attached with thiophene (FST) using the hybrid functional B3LYP and 6-311G basis sets. When donating groups are attached to the molecular dye, the bond lengths are slightly decreased which is important for easy transfer of electron from donating to the accepting group. For all dyes, highest occupied molecular orbital/lowest occupied molecular orbital analysis results in positive outcomes upon electron injection to semiconductors and subsequent dye regeneration by the electrolyte. The ionization potential increases with increasing conjugation; therefore, the molecular dye attached to thiophene has the highest ionization potential. Meanwhile, a donating group with increased conjugation results in low electron affinity.

A new phosphorescent heteroleptic cuprous complex with a neutral 2-methylquinolin-8-ol ligand: synthesis, structure characterization, properties and TD–DFT calculations

2017 ◽  
Vol 73 (6) ◽  
pp. 486-491 ◽  
Author(s):  
Rong-Er Shou ◽  
Li Song ◽  
Wen-Xiang Chai ◽  
Lai-Shun Qin ◽  
Tian-Gen Wang
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Low Cost ◽  
Structure Characterization ◽  
Yellow Emission ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Ligand Charge Transfer ◽  
Td Dft ◽  
Cuprous Complex

Luminescent CuI complexes have emerged as promising substitutes for phosphorescent emitters based on Ir, Pt and Os due to their abundance and low cost. The title heteroleptic cuprous complex, [9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene-κ2 P,P](2-methylquinolin-8-ol-κ2 N,O)copper(I) hexafluorophosphate, [Cu(C10H9NO)(C39H32OP2)]PF6, conventionally abbreviated as [Cu(Xantphos)(8-HOXQ)]PF6, where Xantphos is the chelating diphosphine ligand 9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene and 8-HOXQ is the N,O-chelating ligand 2-methylquinolin-8-ol that remains protonated at the hydroxy O atom, is described. In this complex, the asymmetric unit consists of a hexafluorophosphate anion and a whole mononuclear cation, where the CuI atom is coordinated by two P atoms from the Xantphos ligand and by the N and O atoms from the 8-HOXQ ligand, giving rise to a tetrahedral CuP2NO coordination geometry. The electronic absorption and photoluminescence properties of this complex have been studied on as-synthesized samples, whose purity had been determined by powder X-ray diffraction. In the detailed TD–DFT (time-dependent density functional theory) studies, the yellow emission appears to be derived from the inter-ligand charge transfer and metal-to-ligand charge transfer (M+L′)→LCT excited state (LCT is ligand charge transfer).

scholarly journals Tris-{Hydridotris(1-pyrazolyl)borato}lanthanide Complexes: Synthesis, Spectroscopy, Crystal Structure and Bonding Properties

Inorganics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 44
Author(s):  
Christos Apostolidis ◽  
Attila Kovács ◽  
Alfred Morgenstern ◽  
Jean Rebizant ◽  
Olaf Walter
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Joint Analysis ◽  
Energy Decomposition ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Coordination Sites ◽  
Bonding Properties ◽  
Straightforward Interpretation

Complexes of trivalent lanthanides (Ln) with the hydridotris(1-pyrazolyl)borato (Tp) ligand Ln[η3-HB(N2C3H3)3]3 (LnTp3) were subjected to a joint experimental–theoretical analysis. X-ray diffraction experiments have been performed on CeTp3, NdTp3, SmTp3, GdTp3, and TbTp3 in the nine-fold coordination and on DyTp3, HoTp3, ErTp3, TmTp3, YbTp3, and LuTp3 in the eight-fold coordination form. Density functional theory (DFT) calculations were carried out for all 15 LnTp3 complexes. They extended the X-ray diffraction data available on the LnTp3 compounds and facilitated a straightforward interpretation of trends in the structural parameters. As a result of the joint analysis, significant steric strain in the equatorial coordination sites of the nine-coordinate structures was recognized. Trends in the bonding properties were elucidated by energy decomposition and quantum theory of atoms in molecules (QTAIM) analysis of the electron density distribution. These results revealed the major electrostatic character of the Ln…Tp bonding and fine variation of charge transfer effects across the Ln row.

scholarly journals Computational Exploration of Spectroscopic and Hydrogen Bonding Analysis of Direct Orange 26 Dye in Combination with Experimental and TD-DFT Calculations.

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

Abstract The importance of this study stems from, it concentrates on new approach applying both practical and theoretical aspects to study structure of Direct orange dye 26 (DO-26) as an important dye widely used for dyeing of cotton or viscose for red orange direct printing. It also can be used for silk, wool, polyvinyl alcohol, polyamide fiber fabric and pulp dyeing. It proficiently compare practical with theoretical results of structural identification of the given important dye, via carful inspection of various phenomena detected in its two symmetrical arms around urea center. Direct orange dye 26 (DO-26) structure has been studied applying both practical spectroscopic and theoretical investigations. DFT-B3LYP/6-311++G(d,p) calculations are performed to investigate its structure, and the electronic vibrational properties. Correlation is found between experimental and calculated data. An intra-molecular hydrogen bonding interaction had been detected and characterized in dye skeleton using Atoms-in-molecule analysis employment. 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 and FT-IR spectral data of the dye DO-26 (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.

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