scholarly journals Synthesis and Density Functional Theory Studies of Azirinyl and Oxiranyl Functionalized Isoindigo and (3Z,3’Z)-3,3’-(ethane-1,2-diylidene)bis(indolin-2-one) Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3649
Author(s):  
Gholamhossein Khalili ◽  
Patrick McCosker ◽  
Timothy Clark ◽  
Paul Keller
Keyword(s):  
Density Functional ◽  
Functional Group ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
Disubstituted Derivative ◽  
Td Dft ◽  
Vertical Excitation Energy ◽  
Homo Lumo

The design and synthesis of functionalized isoindigo compounds by reaction of isoindigo with (S)-glycidyl tosylate, epibromohydrin, 2-(bromomethyl)-1-(arylsulfonyl)aziridine, and 2-(bromomethyl)-1-(alkylsulfonyl)aziridine in the presence of MeONa proceed under mild conditions in moderate yields. (3Z,3’Z)-3,3’-(Ethane-1,2-diylidene)bis(1-(oxiran-2-ylmethyl)indolin-2-one), with an extended central olefin π-conjugated moiety was also reacted with methyl-oxiranes to give the corresponding N,N’-disubstituted derivative. Calculations with DFT and TD-DFT of hypothetical isoindigo-thiophene DA molecules with various electron withdrawing substituents, including aziridine, oxirane, nitrile, carbonyl, and sulfonate, indicated that the proximity and strength of the functional group have a significant effect on the HOMO, LUMO, vertical excitation energy, and oscillator strength of the π–π* transitions.

scholarly journals Plausible Pnicogen Bonding of epi-Cinchonidine as a Chiral Scaffold in Catalysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Zakir Ullah ◽  
Kang Kim ◽  
Arramshetti Venkanna ◽  
Hye su Kim ◽  
Moon Il Kim ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Cinchona Alkaloid ◽  
Hydroxyl Group ◽  
Quinoline Ring ◽  
Functional Theory ◽  
Pnicogen Bond ◽  
Covalent Interaction ◽  
Td Dft ◽  
Homo Lumo

As a non-covalent interaction of a chiral scaffold in catalysis, pnicogen bonding of epi-cinchonidine (epi-CD), a cinchona alkaloid, was simulated to consider whether the interaction can have the potential controlling enantiotopic face like hydrogen bonding. Among five reactive functional groups in epi-CD, two stable complexes of the hydroxyl group (X-epi-CD1) at C17 and of the quinoline ring (X-epi-CD2) at N16 with pnictide family analytes [X = substituted phosphine (PX), i.e., F, Br, Cl, CF3, CN, HO, NO2, and CH3, and pnictide family analytes, i.e., PBr3, BiI3, SbI3, and AsI3] were predicted with intermolecular interaction energies, charge transfer (QMulliken and QNBO), and band gap energies of HOMO–LUMO (Eg) at the B3LYP/6-31G(d,p) level of density functional theory. It was found that the dominant site of pnicogen bonding in epi-CD is the quinoline ring (N16 atom) rather than the hydroxyl group (O36 atom). In addition, the UV-Vis spectra of the complex were calculated by time-dependent density functional theory (TD-DFT) at the B3LYP/6-31+G(d,p) level and compared with experimental measurements. Through these calculations, two intermolecular interactions (H-bond vs. pnicogen bond) of epi-CD were compared.

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.

Design and synthesis of new Ru-complexes as potential photo-sensitizers: experimental and TD-DFT insights

RSC Advances ◽  
2016 ◽  
Vol 6 (73) ◽  
pp. 69647-69657 ◽  
Author(s):  
Walid Sharmoukh Walid Sharmoukh ◽  
Walid M. I. Hassan ◽  
Philippe C. Gros ◽  
Nageh K. Allam
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Design And Synthesis ◽  
Td Dft ◽  
Ru Complexes

Design of photosensitizers aided by density functional theory calculations.

scholarly journals Functional Group Effects on the HOMO–LUMO Gap of g-C3N4

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 589 ◽  
Author(s):  
Hao Li ◽  
Zhien Zhang ◽  
Yulu Liu ◽  
Wanglai Cen ◽  
Xubiao Luo
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Band Gap ◽  
Density Functional ◽  
Carbon Nitride ◽  
Functional Group ◽  
Functional Theory ◽  
Metal Free ◽  
Homo Lumo ◽  
Group Effects

Graphitic carbon nitride (g-C3N4) is a promising semiconductor material which has been widely studied in nanoscience. However, the effect of modifying the performance of g-C3N4 is still under debate. In this communication, we show the size and functional group effects on the g-C3N4 using density functional theory (DFT) calculations. It was found that a molecule with six repeated g-C3N4 units (g-C3N4-6) could be the smallest unit that converges to the limit of its HOMO–LUMO gap. Calculations of g-C3N4-6 with varying numbers of substituted C≡N, C=O, and O−H functional groups show that C≡N and C=O could narrow down the HOMO–LUMO gap, while O−H could slightly raise the gap. This study shows that the change of substituents could tune the band gap of g-C3N4, suggesting that rationally modifying the substituent at the edge of g-C3N4-based materials could help to significantly increase the photocatalytic properties of a metal-free g-C3N4.

scholarly journals Highly Diastereo- and Enantioselective Synthesis of Quinuclidine Derivatives by an Iridium-Catalyzed Intramolecular Allylic Dearomatization Reaction

CCS Chemistry ◽  
2019 ◽  
pp. 106-116 ◽  
Author(s):  
Lin Huang ◽  
Yue Cai ◽  
Hui-Jun Zhang ◽  
Chao Zheng ◽  
Li-Xin Dai ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Catalytic System ◽  
Density Functional ◽  
Functional Group ◽  
Enantioselective Synthesis ◽  
Large Array ◽  
Functional Theory ◽  
Mild Conditions ◽  
Group Diversity

Asymmetric construction of quinuclidine derivatives has been realized by an iridium-catalyzed allylic dearomatization reaction. The catalytic system, derived from [Ir(cod)Cl] 2 and the Feringa ligand, tolerates a broad range of substrates. A large array of quinuclidine derivatives can be obtained under mild conditions in good to excellent yields (68%–96%), diastereoselectivity (up to >20/1 dr), and enantioselectivity (up to >99% ee). These products feature versatile functional group diversity and can undergo diverse transformations. A model that accounts for the origin of the stereoselectivity has been proposed based on density functional theory (DFT) calculations.

scholarly journals Computational Chemical Study of Pigment of Mangosteen (Garcinia mangostana) Rind Extract as Dye Compound in Dye-Sensitized Solar Cell (DSSC)

2021 ◽  
Vol 10 (1) ◽  
pp. 41-46
Author(s):  
Didik Krisdiyanto ◽  
Sudarlin Sudarlin ◽  
Hikmah Supriyati
Keyword(s):  
Bond Length ◽  
Density Functional ◽  
Chemical Study ◽  
Energy Difference ◽  
Molecular Spectra ◽  
Garcinia Mangostana ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Homo Lumo

The electronic transition processes of α-mangostin and β-mangostin as dye compounds in DSSC and their ability to transfer electrons to semiconductors have been studied in theory. The research was carried out computationally using the NwChem application. The methods used are Density Functional Theory (DFT) for structure optimization and Time-Dependent DFT (TD-DFT) for electronic transitions. The results showed that the energy of HOMO β-mangostin was lower that it was more stable or easier to form bonds with semiconductors. Likewise, its LUMO energy is lower than α-mangostin that it is easier to inject electrons into the semiconductor. The energy difference of HOMO-LUMO β-mangostin is smaller than α-mangostin. This shows that β-mangostin is more easily excited or more efficient in exciting solar energy to convert it into electricity. This is consistent with the molecular spectra where λmaxβ-mangostin is at a higher wavelength. Orbital analysis shows electron injection of α-mangostin and β-mangostin into the semiconductor via double O atoms in each molecule. The injection is influenced by the bond length, where the bond length of α-mangostin to TiO2 is smaller than that of β-mangostin to TiO2.

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

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.

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