scholarly journals The effect of the fused-ring substituent on anthracene chalcones: crystal structural and DFT studies of 1-(anthracen-9-yl)-3-(naphthalen-2-yl)prop-2-en-1-one and 1-(anthracen-9-yl)-3-(pyren-1-yl)prop-2-en-1-one

Author(s):  
Dian Alwani Zainuri ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad

The title chalcone compounds, C27H18O (I) and C33H20O (II), were synthesized using a Claisen–Schmidt condensation. Both compounds display an s-trans configuration of the enone moiety. The crystal structures feature intermolecular C—H...O and C—H...π interactions. Quantum chemical analysis of density functional theory (DFT) with a B3LYP/6–311++G(d,p) basis set has been employed to study the structural properties of the compound. The effect of the intermolecular interactions in the solid state are responsible for the differences between the experimental and theoretical optimized geometrical parameters. The small HOMO–LUMO energy gap in (I) (exp : 3.18 eV and DFT: 3.15 eV) and (II) (exp : 2.76 eV and DFT: 2.95 eV) indicates the suitability of these compounds for optoelectronic applications. The intermolecular contacts and weak contributions to the supramolecular stabilization are analysed using Hirshfeld surface analysis.

2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa

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.


2017 ◽  
Vol 95 (5) ◽  
pp. 580-589 ◽  
Author(s):  
N. Kalaiarasi ◽  
S. Manivarman

Vibrational and spectral characterizations of 2-(6-oxo-2-thioxo tetrahydro pyrimidin-4(1h)-ylidene) hydrazine carboxamide (OTHHPYHC) were experimentally presented for the ground state using FTIR and FT-Raman and theoretically presented by density functional theory (DFT) using B3LYP correlation function with the basis set 6-31G(d,p). The geometrical parameters, energies, and wavenumbers have been obtained. The fundamental assignments were performed on the basis of total energy distribution. The first order hyperpolarizability (β0) and relative properties (β, α0, and Δα) were calculated using B3LYP/6-31G(d, p) method. Solidity of the molecule due to hyperconjugative interactions and charge delocalization has been analysed using natural bond orbital (NBO) analysis. The charge distribution and electron transfer from bonding to antibonding orbitals and electron density in the σ* and π* antibonding orbitals confirms interaction within the molecule. In addition to this, Mulliken population and HOMO–LUMO analysis have been used to support the information of structural properties.


Author(s):  
Ainizatul Husna Anizaim ◽  
Muhamad Fikri Zaini ◽  
Muhammad Adlan Laruna ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad

In the title compound, C18H12O3S2, synthesized by the Claisen–Schmidt condensation method, the essentially planar chalcone unit adopts an s-cis configuration with respect to the carbonyl group within the ethylenic bridge. In the crystal, weak C—H...π interactions connect the molecules into zigzag chains along the b-axis direction. The molecular structure was optimized geometrically using Density Functional Theory (DFT) calculations at the B3LYP/6–311 G++(d,p) basis set level and compared with the experimental values. Molecular orbital calculations providing electron-density plots of HOMO and LUMO molecular orbitals and molecular electrostatic potentials (MEP) were also computed both with the DFT/B3LYP/6–311 G++(d,p) basis set. The experimental energy gap is 3.18 eV, whereas the theoretical HOMO–LUMO energy gap value is 2.73 eV. Hirshfeld surface analysis was used to further investigate the weak interactions present.


Fourier Transfer infrared and Raman spectra in the range of 4000-400 cm-1 and 3500-50 cm-1 were recorded to study the vibrational spectra of 5-chloro-2-hydroxyacetophenone (CHAP). Using density functional theory (DFT/B3LYP) with 6-31+G(d,p) and 6-311++G(d,p) basis sets the various geometrical parameters such as Raman activities, infrared intensities and optimum frequencies were calculated. The HOMO-LUMO energy gap has been computed which confirms the charge transfer of the molecular system. Mulliken’s atomic charges associated with each atom and thermodynamic parameters have also been reported with the same level of DFT.


2021 ◽  
Author(s):  
Thangarasu S ◽  
Siva V ◽  
Asath Bahadur S ◽  
Athimoolam S

Abstract In this work, 3-nitroanilinium nitrate (3NAN) has been synthesized and crystallized successfully by solution growth combined with solvent evaporation technique. 3NAN molecular structure has been optimized with Density Functional Theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311 + + G(d,p) basis set. The geometrical parameters of the title molecules have been analyzed. The computed vibrational spectra were compared with experimental result which show appreciable agreement. Thermal stability of the crystal was analyzed with TGA/DTA and the melting points of the salt identified at 209 ºC. HOMO-LUMO energy calculations have shown the charge transfer within the molecu le. The possible pharmaceutical/biological activity of the salts confirmed by the Frontier Molecular Orbital (FMO) analysis have lower band gap value. The antimicrobial activity of grown crystals were tested against certain potentially threatening microbes.


Author(s):  
Muhamad Fikri Zaini ◽  
Ibrahim Abdul Razak ◽  
Mohamad Zahid Anis ◽  
Suhana Arshad

The asymmetric unit of the title halogenated chalcone derivative, C15H10BrFO, contains two independent molecules, both adopting an s-cis configuration with respect to the C=O and C=C bonds. In the crystal, centrosymmetrically related molecules are linked into dimers via intermolecular hydrogen bonds, forming rings with R 1 2(6), R 2 2(10) and R 2 2(14) graph-set motifs. The dimers are further connected by C—H...O interactions into chains parallel to [001]. A Hirshfeld surface analysis suggests that the most significant contribution to the crystal packing is by H...H contacts (26.3%). Calculations performed on the optimized structure obtained using density functional theory (DFT) at B3LYP with the 6–311 G++(d,p) basis set reveal that the HOMO–LUMO energy gap is 4.12 eV, indicating the suitability of this crystal for optoelectronic and biological applications. The nucleophilic and electrophilic binding site regions are elucidated using the molecular electrostatic potential (MEP).


2016 ◽  
Vol 35 (2) ◽  
pp. 169
Author(s):  
Ufuk Çoruh ◽  
Reşat Ustabaş ◽  
Hakkı Türker Akçay ◽  
Emra Menteşe ◽  
Ezequiel M. Vazquez Lopez

In this study, 4-[(4-methyl-5-phenyl-4<em>H</em>-1,2,4-triazol-3-yl)sulfanyl]benzene-1,2-dicarbonitrile was synthesized and its molecular structure was characterized by means of FT-IR and X-ray diffraction methods. The crystal is monoclinic and belongs to the P21/n space group. There are three weak intermolecular C-H…N type hydrogen bonds in the molecular structure. The geometrical parameters, vibration frequencies, HOMO–LUMO energies, and molecular electrostatic potential (MEP) map of the compound (3) in ground state were calculated by using density functional theory (DFT/B3LYP) with the 6-311G(d) basis set. Calculated geometrical parameters were compared with X-ray diffraction geometric parameters. On the other hand, theoretical and experimental FT-IR results were also compared.


2021 ◽  
Vol 12 (4) ◽  
pp. 459-468
Author(s):  
Shilpa Mallappa Somagond ◽  
Ahmedraza Mavazzan ◽  
Suresh Fakkirappa Madar ◽  
Madivalagouda Sannaikar ◽  
Shankar Madan Kumar ◽  
...  

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.


2018 ◽  
Vol 74 (8) ◽  
pp. 1087-1092 ◽  
Author(s):  
Dian Alwani Zainuri ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad

The title compounds, C24H18O2 and C24H17FO2, were synthesized using the Claisen–Schmidt condensation method and characterized by UV–Vis spectroscopy. Weak intermolecular C—H...O, C—H...π and π–π hydrogen-bonding interactions help to stabilize the crystal structures of both compounds. The geometrical parameters obtained from the molecular structure were optimized using density functional theory (DFT) calculations at the B3LYP/6–311++G(d,p) level, showing a good correlation with the experimental results. The small HOMO–LUMO energy gaps of 3.11 and 3.07 eV enhances the non-linear responses of these molecular systems.


2021 ◽  
pp. 3323-3335
Author(s):  
Mustafa M. Kadhim ◽  
Layla A. Al. Juber ◽  
Ahmed S. M. Al-Janabi

    Seven Zn-dithiocarbamate complexes were suggested as corrosion inhibitors. Density functional theory (DFT) was used to predict the ability of inhibition. Room temperature conditions were applied to suggest the optimization of complexes, physical properties, and corrosion parameters. In addition, the HOMO, LUMO, dipole moment, energy gap, and other parameters were used to compare the inhibitors efficiency. Gaussian 09 software with LanL2DZ basis set was used. Total electron density (TED) and electrostatic surface potential (ESP) were utilized to show the sites of adsorption according to electron density.


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