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Journal ArticleDOI

Quantum chemical and spectroscopic (FT-IR and FT-Raman) investigations of 3-methyl-3h-imidazole-4-carbaldehyde.

TL;DR: Optimize geometric parameters, conformational equilibria, normal mode frequencies, and corresponding vibrational assignments of 3M3HI4C were theoretically examined by quantum chemical methods for the first time and the most stable conformer of the title compound was determined.
About: This article is published in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy.The article was published on 2014-12-10. It has received 11 citations till now. The article focuses on the topics: Polarizable continuum model & HOMO/LUMO.
Citations
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Journal ArticleDOI
TL;DR: In this article, two Gemini cationic surfactants have been prepared based on waste frying oil with full characterization by different spectral tools (FTIR, 1H NMR and 13C NMR), and investigated as sustainable inhibitors for N80-steel corrosion in 1.0 M sulphuric acid.

111 citations

Journal ArticleDOI
TL;DR: In this paper, a density functional theory (DFT) with two functionals, namely B3lyP and CAM-B3LYP with the 6-311-G(d,p) basis set was performed on six 2-amino-5-alkyl-1,3,4-thiadiazole derivatives (IC-2 to IC-13) used as corrosion inhibitors for steel in 1.0-M H2SO4 solution.

75 citations

Journal ArticleDOI
TL;DR: In this paper, the anticorrosion potential of a chemisorbed film formed from 3-imidazol-1-ylpropan-1amine (IMPA) against the degradation of X70 steel in 1 M HCl has been investigated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques.
Abstract: The anticorrosion potential of a chemisorbed film formed from 3-imidazol-1-ylpropan-1-amine (IMPA) against the degradation of X70 steel in 1 M HCl has been investigated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. IMPA has been found to reduce the corrosion of X70 in the aqueous medium at pH 0 to a great extent; an inhibition efficiency (IE%) up to 90% has been achieved for 500 ppm IMPA concentration at room temperature. Corrosion inhibition by IMPA is concentration-dependent and becomes more stable by virtue of adsorption of IMPA film on the X70 substrate. This adsorption phenomenon has been probed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and infra-red (IR) spectroscopy. The formation of this film on the X70 surface fosters improved impedance against the flow of ionic currents of corrosive ions and molecules. IMPA acted as a mixed-type film-forming inhibitor as demonstrated from the results of potentiodynamic scans. The mechanism of X70 corrosion inhibition has been proposed using quantum structure/activity relations to explain the extent of influence of the molecular structure of IMPA on the corrosion inhibition of the IMPA film.

28 citations

Journal ArticleDOI
TL;DR: In this paper, a facile approach towards spherical SnSe2 nanodots/graphene nanocomposites via an ionic liquid media assembly process was presented, which involved an easily scaled-up microwave-assisted ionothermal synthesis of SnSex Nanodots (NDs) as precursors by the reaction of elementary tin and selenium in Bmmim)Cl (Bmmim = 1-butyl-2,3-dimethyl imidazolium) followed by an assembly process under ambient conditions and subsequent thermal treatment.
Abstract: Presented here is a facile approach towards spherical SnSe2 nanodots/graphene nanocomposites via an ionic liquid media assembly process, which involved an easily scaled-up microwave-assisted ionothermal synthesis of SnSex nanodots (NDs) as precursors by the reaction of elementary tin and selenium in (Bmmim)Cl (Bmmim = 1-butyl-2,3-dimethyl imidazolium) followed by an assembly process under ambient conditions and subsequent thermal treatment. The regulation of the content of SnSe2 NDs could be conveniently achieved by varying the ratio of ND precursor to graphene oxide (GO). As evidenced by TG-MS and FTIR analysis, the assembly process could be attributed to the electrostatic interaction between the anionic GO and the positively charged SnSex NDs, which are fixed in the IL cation layer around the NDs as a medium. This conclusion was further confirmed by the TEM micrographs, which showed a constant particle size in the precursor and in the nanocomposites after thermal treatment. Lithium storage characterizations showed that the capacity of the as-prepared nanocomposite remained at 659 mA h g−1 after 30 cycles at a current density of 150 mA g−1, which is 1.5-times better than the theoretical capacity of SnSe2 (426 mA h g−1) and superior to the capacities of the previously reported SnSe2 nanoplate/graphene composite and many other tin selenide electrodes. Thus, the new approach represents a promising, simple, and scalable synthetic protocol for the fabrication of lamellar metal dichalcogenide (LMD) NDs/graphene nanocomposites.

22 citations

Journal ArticleDOI
TL;DR: In this article, the theoretical and experimental studies were carried out on 7-fluoroisatin, 7-bromoisatin and 1-methylisatin using FT-Raman and FT-IR spectra.

21 citations

References
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Journal ArticleDOI
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
Abstract: Despite the remarkable thermochemical accuracy of Kohn–Sham density‐functional theories with gradient corrections for exchange‐correlation [see, for example, A. D. Becke, J. Chem. Phys. 96, 2155 (1992)], we believe that further improvements are unlikely unless exact‐exchange information is considered. Arguments to support this view are presented, and a semiempirical exchange‐correlation functional containing local‐spin‐density, gradient, and exact‐exchange terms is tested on 56 atomization energies, 42 ionization potentials, 8 proton affinities, and 10 total atomic energies of first‐ and second‐row systems. This functional performs significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.

87,732 citations

Journal ArticleDOI
TL;DR: Numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, show that density-functional formulas for the correlation energy and correlation potential give correlation energies within a few percent.
Abstract: A correlation-energy formula due to Colle and Salvetti [Theor. Chim. Acta 37, 329 (1975)], in which the correlation energy density is expressed in terms of the electron density and a Laplacian of the second-order Hartree-Fock density matrix, is restated as a formula involving the density and local kinetic-energy density. On insertion of gradient expansions for the local kinetic-energy density, density-functional formulas for the correlation energy and correlation potential are then obtained. Through numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, it is demonstrated that these formulas, like the original Colle-Salvetti formulas, give correlation energies within a few percent.

84,646 citations

Journal ArticleDOI
TL;DR: In this paper, the Hartree and Hartree-Fock equations are applied to a uniform electron gas, where the exchange and correlation portions of the chemical potential of the gas are used as additional effective potentials.
Abstract: From a theory of Hohenberg and Kohn, approximation methods for treating an inhomogeneous system of interacting electrons are developed. These methods are exact for systems of slowly varying or high density. For the ground state, they lead to self-consistent equations analogous to the Hartree and Hartree-Fock equations, respectively. In these equations the exchange and correlation portions of the chemical potential of a uniform electron gas appear as additional effective potentials. (The exchange portion of our effective potential differs from that due to Slater by a factor of $\frac{2}{3}$.) Electronic systems at finite temperatures and in magnetic fields are also treated by similar methods. An appendix deals with a further correction for systems with short-wavelength density oscillations.

47,477 citations

Journal ArticleDOI
TL;DR: In this article, a perturbation theory for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation was developed, and it was shown by this development that the first order correction for the energy and the charge density of the system is zero.
Abstract: A perturbation theory is developed for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation. It is shown by this development that the first order correction for the energy and the charge density of the system is zero. The expression for the second-order correction for the energy greatly simplifies because of the special property of the zero-order solution. It is pointed out that the development of the higher approximation involves only calculations based on a definite one-body problem.

12,067 citations

Book
30 Sep 1997
TL;DR: In this article, the CHEC III is organized in 15 volumes and closely follows the organization used in the previous edition: Volumes 1 and 2: Cover respectively three and four-membered heterocycles, together with all fused systems containing a three- or four-measured heterocyclic ring.
Abstract: CHEC III is organized in 15 Volumes and closely follows the organization used in the previous edition: Volumes 1 and 2: Cover respectively three- and four-membered heterocycles, together with all fused systems containing a three- or four-membered heterocyclic ring. Volume 3: Five-membered rings with one heteroatom together with their benzo- and other carbocyclic-fused derivatives. Volumes 4, 5 and 6: Cover five-membered rings with two heteroatoms, and three or more heteroatoms, respectively, each with their fused carbocyclic compounds. Volumes 7, 8 and 9: Dedicated to six-membered rings with one, two, and more than two heteroatoms, respectively, again with the corresponding fused carbocylic compounds. Volumes 10, 11 and 12: Cover systems containing at least two directly fused heterocyclic five- and/or six-membered rings: of these Volume 10 deals with bi-heterocyclic rings without a ring junction heteroatom, and Volume 11 deals with 5:5 and 5:6 fused rings systems with at least one ring junction nitrogen, while Volume 12 is devoted to all other systems of five and/or six-membered fused or spiro heterocyclic rings with ring junction heteroatoms. Volumes 13 and 14: Seven-membered and larger heterocyclic rings including all their fused derivatives (except those containing three- or four-membered heterocyclic rings which are included in Volume 1 and 2, respectively). Volume 15: Author, ring and subject indexes.

8,174 citations