scholarly journals Molecular structure and spectra of danthron and emodin studied by FTIR, Raman spectroscopy and DFT techniques

2021 ◽  
Vol 61 (1) ◽  
Author(s):  
B.K. Barik ◽  
H.M. Mallya ◽  
R.K. Sinha ◽  
S. Chidangil
Keyword(s):  
Vibrational Frequency ◽  
Density Functional ◽  
Theoretical Data ◽  
Basis Set ◽  
Theoretical Studies ◽  
Vibrational Modes ◽  
Functional Theory ◽  
Intramolecular Hydrogen ◽  
Experimental And Theoretical Studies ◽  
Stable Structures

In this work, experimental and theoretical studies on danthron and emodin are presented. Experimentally, Fourier transform infrared (FTIR), Raman and UV–Vis spectra of danthron and emodin were recorded. The structure and vibrational frequencies of the molecules were calculated using density functional theory (DFT) with the B3LYP functional using the triple zeta (TZVP) basis set. Among various possible structures of danthron and emodin, it was found that the most stable structures involve intramolecular hydrogen bonds between two OH and C=O groups. The theoretical IR spectra of the most stable conformations of danthron and emodin correlate well with their experimental FTIR. Detailed vibrational frequency analysis was done for all the vibrational modes obtained and were assigned to the ring vibrations along with the stretching and bending of specific bond vibrations. The bands obtained from the experimental FTIR and Raman spectra of both the molecules correlate well with their theoretical data.

Electronic Structure, Nonlinear Optical Properties, and Vibrational Analysis of Ethyl benzoate by Density Functional Theory

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Tanveer Hasan ◽  
P. K. Singh
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Ethyl Benzoate ◽  
Computational Method ◽  
Basis Set ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Functional Theory ◽  
Vibrational Bands

This work deals with the vibrational spectroscopy of Ethyl benzoate (C9H10O2). The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) using standard HF/6-31G(d,p) and B3LYP/6-31G(d,p) methods and basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.

Evaluation of N—H...S and N—H...π interactions inO,O′-diethylN-(2,4,6-trimethylphenyl)thiophosphate: a combination of X-ray crystallographic and theoretical studies

2018 ◽  
Vol 74 (7) ◽  
pp. 847-855 ◽  
Author(s):  
Elham Torabi Farkhani ◽  
Mehrdad Pourayoubi ◽  
Mohammad Izadyar ◽  
Pavel V. Andreev ◽  
Ekaterina S. Shchegravina
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Basis Set ◽  
Theoretical Studies ◽  
Functional Theory ◽  
X Ray

In the crystal structure ofO,O′-diethylN-(2,4,6-trimethylphenyl)thiophosphate, C13H22NO2PS, two symmetrically independent thiophosphoramide molecules are linked through N—H...S and N—H...π hydrogen bonds to form a noncentrosymmetric dimer, withZ′ = 2. The strengths of the hydrogen bonds were evaluated using density functional theory (DFT) at the M06-2X level within the 6-311++G(d,p) basis set, and by considering the quantum theory of atoms in molecules (QTAIM). It was found that the N—H...S hydrogen bond is slightly stronger than the N—H...π hydrogen bond. This is reflected in differences between the calculated N—H stretching frequencies of the isolated molecules and the frequencies of the same N—H units involved in the different hydrogen bonds of the hydrogen-bonded dimer. For these hydrogen bonds, the corresponding charge transfers,i.e.lp (or π)→σ*, were studied, according to the second-order perturbation theory in natural bond orbital (NBO) methodology. Hirshfeld surface analysis was applied for a detailed investigation of all the contacts participating in the crystal packing.

scholarly journals Anion-Binding-Induced Electrochemical Signal Transduction in Ferrocenylimidazolium: Combined Electrochemical Experimental and Theoretical Investigation

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 238 ◽  
Author(s):  
Tan-Qing Weng ◽  
Yi-Fan Huang ◽  
Lou-Sha Xue ◽  
Jie Cheng ◽  
Shan Jin ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Density Functional Theory ◽  
Dft Calculations ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Anion Binding ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Electrochemical Signal ◽  
Experimental And Theoretical Studies

Five ferrocene alkymethylimidazolium cations 1a–1d and 2 with different alkyl spacer lengths were reinvestigated using voltammetry and density functional theory (DFT) calculations. The voltammetric responses of ligand 2 toward various anions are described in detail. An interesting and unprecedented finding from both experimental and theoretical studies is that coupled electron and intramolecular anion (F−) transfer may be present in these molecules. In addition, it was also observed that, in these studied molecules, the electrostatic attraction interaction toward F− would effectively vanish beyond 1 nm, which was previously reported only for cations.

scholarly journals Experimental and theoretical study of a novel naphthoquinone Schiff base

2018 ◽  
Vol 16 (1) ◽  
pp. 1115-1121
Author(s):  
Güvenç Görgülü
Keyword(s):  
Density Functional Theory ◽  
Schiff Base ◽  
Density Functional ◽  
Active Agent ◽  
Theoretical Data ◽  
Basis Set ◽  
Magnetic Data ◽  
Functional Theory ◽  
Ft Ir ◽  
C Nmr

AbstractA novel Schiff base was synthesized and characterized by spectroscopic and theoretical methods. A potentially active agent 4-(2-hydroxy-5-methylphenylimino)naphthalen-1(4H)-one (PINQ) was designed and synthesized. The synthesis was carried out by a condensation reaction of 1-4-naphthoquinone and 2-amino-4-methyl phenol. The spectral and structural properties of the PINQ molecule were investigated by elemental analysis, 1H- and 13C-NMR, FT-IR and Uv-vis spectroscopies. The energetic, atomic, electronic, molecular, vibrational and magnetic data were theoretically obtained using density functional theory (DFT) at B3LYP level with 6-311++G(d,p) basis set. Chemical shifts were calculated using gauge-invariant atomic orbital (GIAO) method. UV-vis spectrum for the title compound was also obtained by time-dependent density functional theory (TD-DFT). The theoretical and experimental results were compared and interpreted. The theoretical data obtained from 1H- and 13C-NMR, FT-IR and Uv-vis spectroscopies were quite compatible with experimental ones.

scholarly journals Vibrational analysis and electronic properties of 2-Decenoic acid and its derivative by first principles

2011 ◽  
Vol 26 (6) ◽  
pp. 367-385 ◽  
Author(s):  
Apoorva Dwivedi ◽  
Anoop Kumar Pandey ◽  
Neeraj Misra
Keyword(s):  
Density Functional ◽  
Royal Jelly ◽  
Vibrational Analysis ◽  
Computational Method ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Vibrational Modes ◽  
Decenoic Acid ◽  
Functional Theory ◽  
Vibrational Dynamics

Royal jelly is the mixture of acids like 2-Decenoic acid (DA), 10-Hydroxy 2-Decenoic acid and many others. 10-HDA possesses strong inhibition to the growth of cancer cells, namely transferable AKR leukaemia, TA3 breast cancer, etc. The equilibrium geometry of 2-Decenoic acid and its derivative 10-Hydroxy 2-Decenoic acid in the ground state have been determined and analyzed by Density functional theory (DFT) employing 6-311 G (d, p) as the basis set. The harmonic frequencies of 2-DA and 10-HDA have also been calculated to understand its complete vibrational dynamics. The study of simulated spectra provides important information about the ability of the computational method to describe the vibrational modes.

scholarly journals The Interaction of Hydrogen with the van der Waals Crystal γ-InSe

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2526 ◽  
Author(s):  
James Felton ◽  
Elena Blundo ◽  
Sanliang Ling ◽  
Joseph Glover ◽  
Zakhar R. Kudrynskyi ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Van Der Waals ◽  
Transition Metal Dichalcogenides ◽  
Ion Source ◽  
Vibrational Modes ◽  
Functional Theory ◽  
Metal Dichalcogenides ◽  
Experimental And Theoretical Studies

The emergence of the hydrogen economy requires development in the storage, generation and sensing of hydrogen. The indium selenide ( γ -InSe) van der Waals (vdW) crystal shows promise for technologies in all three of these areas. For these applications to be realised, the fundamental interactions of InSe with hydrogen must be understood. Here, we present a comprehensive experimental and theoretical study on the interaction of γ -InSe with hydrogen. It is shown that hydrogenation of γ -InSe by a Kaufman ion source results in a marked quenching of the room temperature photoluminescence signal and a modification of the vibrational modes of γ -InSe, which are modelled by density functional theory simulations. Our experimental and theoretical studies indicate that hydrogen is incorporated into the crystal preferentially in its atomic form. This behaviour is qualitatively different from that observed in other vdW crystals, such as transition metal dichalcogenides, where molecular hydrogen is intercalated in the vdW gaps of the crystal, leading to the formation of “bubbles” for hydrogen storage.

Experimental and theoretical studies on the corrosion inhibition of mild steel by some sulphonamides in aqueous HCl

RSC Advances ◽  
2015 ◽  
Vol 5 (36) ◽  
pp. 28743-28761 ◽  
Author(s):  
Lutendo C. Murulana ◽  
Mwadham M. Kabanda ◽  
Eno E. Ebenso
Keyword(s):  
Density Functional Theory ◽  
Weight Loss ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Electrochemical Impedance ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Inhibition Studies ◽  
Experimental And Theoretical Studies

Corrosion inhibition studies of mild steel in aqueous HCl by some sulphonamides have been investigated using weight loss, potentiodynamic polarization (PDP), Electrochemical Impedance Spectroscopy (EIS) and Density Functional Theory (DFT).

Experimental and theoretical studies on competitive adsorption of aromatic compounds on reduced graphene oxides

2016 ◽  
Vol 4 (15) ◽  
pp. 5654-5662 ◽  
Author(s):  
Shujun Yu ◽  
Xiangxue Wang ◽  
Yuejie Ai ◽  
Xiaoli Tan ◽  
Tasawar Hayat ◽  
...  
Keyword(s):  
Density Functional ◽  
Competitive Adsorption ◽  
Theoretical Studies ◽  
Batch Experiments ◽  
Graphene Oxides ◽  
Functional Theory ◽  
Reduced Graphene ◽  
Reduced Graphene Oxides ◽  
The Individual ◽  
Experimental And Theoretical Studies

The individual and competitive adsorption of benzene, aniline and naphthylamine on reduced graphene oxides were studied by batch experiments and theoretical density functional theory (DFT).

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