scholarly journals New nematogenic conical-shaped supramolecular H-bonded complexes for solar energy investigations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sobhi M. Gomha ◽  
Hoda A. Ahmed ◽  
Mohamed Shaban ◽  
Tariq Z. Abolibda ◽  
Khalid Abdulaziz Alharbi ◽  
...  
Keyword(s):  
Solar Energy ◽  
Density Functional ◽  
Geometrical Structure ◽  
Energy Gap ◽  
Supramolecular Complexes ◽  
Geometrical Parameters ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Ft Ir ◽  
Flexible Core

AbstractNew conical-shaped geometrical supramolecular H-bonded liquid crystal complexes were formed through 1:2 intermolecular interactions of H-bonding between flexible core (adipic acid, A) and lateral chloro-substituted azopyridines (Bn). The chains of the terminally alkoxy substituted base (n) were changed between 8 and 16 carbons. Mesomorphic and optical examinations of the prepared complexes were measured via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was used to confirm the Fermi bands of the H- bonding interactions. Induced nematogenic mesophases that cover the whole lengths of alkoxy-chains were detected. The non-linear geometries of the designed supramolecular complexes were also confirmed via Density functional theory (DFT) calculations. It was found that the length of terminal alkoxy chain of the base moiety highly affects the geometrical structure of the investigated complexes. Moreover, it increases the thermodynamic energy and influences the geometrical parameters. The electrical properties of each of the acid component (A), the base (B16) and their 1:2 complex (A/2B16) were evaluated using the Keithley measurement-source unit. The optical properties studies showed that the influences in the optical absorption and the reduction of the energy gap of the complex compared to its individual components made the resulted supramolecular H-bonded complex soft material suitable for solar energy investigations.

scholarly journals New Symmetrical U- and Wavy-Shaped Supramolecular H-Bonded Systems; Geometrical and Mesomorphic Approaches

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1420 ◽  
Author(s):  
Laila A. Al-Mutabagani ◽  
Latifah Abdullah Alshabanah ◽  
Hoda A. Ahmed ◽  
Mohamed Hagar ◽  
Khulood A. Abu Al-Ola
Keyword(s):  
Density Functional ◽  
Geometrical Parameters ◽  
Scanning Calorimetry ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Smectic C ◽  
The Density Functional Theory ◽  
Phenyl Rings ◽  
Ft Ir ◽  
Bonded Complexes

New mesomorphic symmetrical 2:1 supramolecular H-bonded complexes of seven phenyl rings were prepared between 4-n-alkoxyphenylazobenzoic acids and 4-(2-(pyridin-3-yl)diazenyl)phenyl nicotinate. Mesomorphic studies of the prepared complexes were investigated using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fermi bands of the formed H-bonded interactions were confirmed by FT-IR spectroscopy. Geometrical parameters for all complexes were performed using the density functional theory (DFT) calculations method. Theoretical results revealed that the prepared H-bonded complexes are in non-linear geometry with U-shaped and wavy-shaped geometrical structures; however, the greater linearity of the wavy-shaped compounds could be the reason for their stability with respect to the U-shaped conformer. Moreover, the stable, wavy shape of supramolecular H-bonded complexes (SMHBCs) has been used to illustrate mesomeric behavior in terms of the molecular interaction. The experimental mesomorphic investigations revealed that all complexes possess enantiotropic smectic C phase. Phases were confirmed by miscibility with a standard smectic C (SmC) compound. A comparison was constructed to investigate the effect of incorporating azophenyl moiety into the mesomeric behavior of the corresponding five-membered complexes. It was found that the addition of the extra phenylazo group to the acid moiety has a great increment of the mesophase stability (TC) values with respect to the monotropic SmC phase of the five aromatic systems to the high stable enantiotropic SmC mesophase.

scholarly journals Chair- and V-Shaped of H-bonded Supramolecular Complexes of Azophenyl Nicotinate Derivatives; Mesomorphic and DFT Molecular Geometry Aspects

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1510 ◽  
Author(s):  
Omaima A. Alhaddad ◽  
Khulood A. Abu Al-Ola ◽  
Mohamed Hagar ◽  
Hoda A. Ahmed
Keyword(s):  
Hydrogen Bonding ◽  
Density Functional ◽  
Liquid Crystalline ◽  
Molecular Geometry ◽  
Supramolecular Complexes ◽  
Scanning Calorimetry ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Ft Ir ◽  
Nematic Phases

New geometrical architectures of chair- and V-shaped supramolecular liquid crystalline complexes were molded through 1:1 intermolecular hydrogen bonding interactions between 4-(4-(hexyloxy)phenylazo)methyl)phenyl nicotinate and 4-alkoxybenzoic acids. The length of terminal alkoxy acid chains varied, n = 6 to 16 carbons. The mesomorphic behaviour of these complexes was examined through differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was carried out to confirm the presence of Fermi bands that appeared for the hydrogen bonding formation. Enantiotropic nematic phases were observed and covered all lengths of alkoxy chains. The geometrical structures of the prepared supramolecular complexes geometries were estimated by Density functional theory (DFT) calculations. The supramolecular complexes I/An are projected to exhibit a nonlinear geometry with V-shaped and chair-shaped geometry. The chair-shaped conformers of I/An were found to be more stable than V-shaped isomeric complexes. Moreover, the effect of the change of the mesogenic core on the mesophase thermal stability (TC) has been investigated by a comparative study of the present azo supramolecular H-bonding LCs (SMHBCs) I/An and our previously reported their Schiff base analogue complexes, II/An. The findings of the DFT illustrated the high impact of CH=N as a mesogenic core on the mesomorphic behavior in terms of the competitive lateral and terminal intermolecular interactions as well as the molecular electrostatic potential (MEP).

scholarly journals Synthetic, Mesomorphic, and DFT Investigations of New Nematogenic Polar Naphthyl Benzoate Ester Derivatives

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2587
Author(s):  
Salma A. Al-Zahrani ◽  
Hoda A. Ahmed ◽  
Mohamed A. El-atawy ◽  
Khulood A. Abu Al-Ola ◽  
Alaa Z. Omar
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Molecular Structures ◽  
Experimental Investigations ◽  
Geometrical Parameters ◽  
Polar Group ◽  
Scanning Calorimetry ◽  
Structural Shape ◽  
Elemental Analyses ◽  
Ft Ir

Four new non-symmetrical derivatives based on central naphthalene moiety, 4-((4–(alkoxy)phenyl) diazenyl)naphthalen–1–yl 4–substitutedbenzoate (In/x), were prepared, and their properties were investigated experimentally and theoretically. The synthesized materials bear two wing groups: an alkoxy chain of differing proportionate length (n = 6 and 16 carbons) and one terminal attached to a polar group, X. Their molecular structures were elucidated via elemental analyses and FT-IR and NMR spectroscopy. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) were carried out to evaluate their mesomorphic properties. The results of the experimental investigations revealed that all the synthesized analogues possess only an enantiotropic nematic (N) mesophase with a high thermal stability and broad range. Density functional theory (DFT) calculations were in accordance with the experimental investigations and revealed that all prepared materials are to be linear and planar. Moreover, the rigidity of the molecule increased when an extra fused ring was inserted into the center of the structural shape, so its thermal and geometrical parameters were affected. Energy gap predictions confirmed that the I16/c derivative is more reactive than other compounds.

scholarly journals New Rod-Like H-Bonded Assembly Systems: Mesomorphic and Geometrical Aspects

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 795
Author(s):  
Laila A. Al-Mutabagani ◽  
Latifah Abdullah Alshabanah ◽  
Hoda A. Ahmed ◽  
Khulood A. Abu Al-Ola ◽  
Mohamed Hagar
Keyword(s):  
Density Functional ◽  
Polarized Light ◽  
Proton Donor ◽  
Proton Acceptor ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of ◽  
Bonded Complexes

Experimental and geometrical approaches of new systems of mesomorphic 1:1 supramolecular H-bonded complexes (SMHBCs) of five rings are discussed. The H-bonding between 4-alkoxyphenylimino benzoic acids (An, as proton acceptor) and 4-(4′–pyridylazophenyl) 4′′-alkoxybenzoates (Bm, as proton donor) were investigated. Mesomorphic behaviors were analyzed by differential scanning calorimetry (DSC) and mesophase textures were identified by polarized light microscopy (POM). H-bonded assembly was established by FT-IR spectroscopic measurements via Fermi band discussion. Thermal and theoretical factors were predicted for all synthesized complexes by density functional theory (DFT) predictions. The results revealed that all prepared complexes were monomorphic, with a broad range of smectic A phases with a high thermal stability of enantiotropic mesophase. Furthermore, DFT stimulations illustrated the experimental results in terms of the influence of the chain length either of the acid or the base component. Many parameters, such as the calculated stability, the dipole moment and the polarizability of the H-bonded complexes, illustrate how these parameters work together to enhance the smectic mesophases with the obtained stability and range.

Theoretical studies on lindqvist polyoxometalates [M6O19]n−(M = Mo, W, n=2; M = V, Nb, Ta, n=8) and derivatives: Electronic structures, stability and bonding

2017 ◽  
Vol 16 (06) ◽  
pp. 1750054 ◽  
Author(s):  
Xiao-Fang Su ◽  
Bo Zhu ◽  
Cai-Xia Wu ◽  
Li-Kai Yan ◽  
Zhong-Min Su
Keyword(s):  
Charge Density ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Density Functional ◽  
Geometrical Structure ◽  
Energy Gap ◽  
Lumo Energy ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The geometrical and electronic structures of [M6O[Formula: see text]][Formula: see text] (M [Formula: see text] Mo, W, [Formula: see text]; M [Formula: see text] V, Nb, Ta, [Formula: see text]) and their derivatives were investigated by using density functional theory methods. The results indicate that the geometrical structure of [V6O[Formula: see text]][Formula: see text] is not different from other Lindqvist-type anions. The energy gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) (HOMO[Formula: see text]LUMO energy gap) of [V6O[Formula: see text]][Formula: see text] is smaller than those of same charge anions, [Nb6O[Formula: see text]][Formula: see text] and [Ta6O[Formula: see text]][Formula: see text]. In addition, the charge density [Formula: see text] of [V6O[Formula: see text]][Formula: see text] is larger when compared with those of other studied clusters. The investigation on the derivatives shows that the valence of V atom (V[Formula: see text] or V[Formula: see text]) and the methoxy ligand influence the HOMO[Formula: see text]LUMO energy gap and the charge density [Formula: see text] of the studied clusters.

scholarly journals Vibrational Spectroscopic and Computational Analysis of 5-chloro-2-hydroxy Acetophenone

2020 ◽  
Vol 8 (4S4) ◽  
pp. 254-259
Keyword(s):  
Density Functional ◽  
Computational Analysis ◽  
Energy Gap ◽  
Molecular System ◽  
Basis Sets ◽  
Geometrical Parameters ◽  
Lumo Energy ◽  
Functional Theory ◽  
Infrared Intensities ◽  
Homo Lumo

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.

scholarly journals Experimental and theoretical studies of 4-[(4-methyl-5-phenyl- 4H1,2,4-triazol-3-yl)sulfanyl]benzene-1,2-dicarbonitrile

2016 ◽  
Vol 35 (2) ◽  
pp. 169
Author(s):  
Ufuk Çoruh ◽  
Reşat Ustabaş ◽  
Hakkı Türker Akçay ◽  
Emra Menteşe ◽  
Ezequiel M. Vazquez Lopez
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Basis Set ◽  
Geometrical Parameters ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Ft Ir ◽  
Experimental And Theoretical Studies ◽  
Homo Lumo

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.

scholarly journals Binary Liquid Crystal Mixtures Based on Schiff Base Derivatives with Oriented Lateral Substituents

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 319 ◽  
Author(s):  
Rua B. Alnoman ◽  
Mohamed Hagar ◽  
Hoda A. Ahmed ◽  
Magdi M. Naoum ◽  
Hanefah A. Sobaih ◽  
...  
Keyword(s):  
Schiff Base ◽  
Binary Mixtures ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Geometrical Parameters ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Schiff Base Derivatives ◽  
Lateral Group ◽  
Molecular Stacking

Binary mixtures of the laterally substituted Schiff base/ester derivatives, namely 4-((2- or 3-) substituted phenyl imino methyl) phenyl-4”-alkoxy benzoates, Ia–d, were prepared and mesomorphically studied by differential scanning calorimetry (DSC) and their mesophases identified by polarized optical microscopy (POM). The lateral group (1-naphthyl, 2-F, 2-Br, 3-F in Ia–d, respectively) is attached to different positions of the phenyl Schiff moiety. The mixtures investigated were made from two differently shaped compounds that differ from each other in the polarity, size, orientation, and relative positions of the lateral group. The results revealed that the binary mixture Ia/Ib (bearing the naphthyl and 2-flouro substituents) exhibited the SmA phase, which covered the whole composition range. For the mixtures Ib/Id (2-F and 2-Br), the isomeric lateral F-group in compound Ib distributed the SmA arrangement of Id. In the Ic/Id mixture bearing two positionally and structurally different substituents, the addition of Ic to Id resulted in solid binary mixtures where its behavior may be attributed to the negligible steric effect of the small electronegative fluorine atom compared to the Br atom. Density functional theory (DFT) theoretical calculations were carried out to estimate the geometrical parameters of individual components and to show the effect of these parameters in the mesophase behavior of the binary system, where the higher dipole moment of Id (6 Debye) may be the reason for its high π–π molecular stacking, which influences its mesophase range and stability.

scholarly journals Synthesis, Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2038
Author(s):  
Laila A. Al-Mutabagani ◽  
Latifah A. Alshabanah ◽  
Hoda A. Ahmed ◽  
Hafsa H. Alalawy ◽  
Mayada H. Al alwani
Keyword(s):  
Density Functional ◽  
Molecular Structures ◽  
Geometrical Parameters ◽  
Molecular Architecture ◽  
Aromatic Rings ◽  
Scanning Calorimetry ◽  
Binary Phase ◽  
Schiff Base Derivatives ◽  
Elemental Analyses ◽  
Ft Ir

Homolog series based on three aromatic rings bearing terminal alkoxy chain of various lengths named 4-(4-(alkoxy)phenylimino)methyl)phenyl nicotinate (An) were synthesized. The alkoxy-chain length changed between 6, 8 and 16 carbons. Mesomorphic and optical properties were carried out via differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Elemental analyses, FT-IR and NMR spectroscopy were carried out to elucidate the molecular structures of the prepared derivatives. Mesomorphic results indicated that all the synthesized homologs (An) are monomorphic possessing the nematic (N) phase enantiotropically with wide thermal stability. Computational simulations were measured via density functional theory (DFT) theoretical calculation tool. The estimated thermal and geometrical parameters are in agreement with the experimental data. By discussing the estimated parameters, it was found that the molecular architecture, dipole moment and the polarizability of the investigated compounds are highly affected by the length of the attached terminal flexible chain and the location of the nitrogen atom in the other terminal aromatic ring. Binary phase diagrams of two corresponding homologs with different proportionating terminals were constructed, and their binary phase physical properties were discussed in terms of the temperature range and stability of the N phase.

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.

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