scholarly journals Synthesis, spectral, crystallographic, and computational investigation of a novel molecular hybrid 3-(1-((benzoyloxy)imino)ethyl)-2H-chromen-2-ones

2021 ◽  
Vol 12 (2) ◽  
pp. 133-146
Author(s):  
Kannan Gokula Krishnan ◽  
Venugopal Thanikachalam
Keyword(s):  
Density Functional ◽  
Vibrational Energy ◽  
Chemical Shifts ◽  
Normal Modes ◽  
Analytical Techniques ◽  
Zero Point ◽  
Dft Method ◽  
Structural Features ◽  
Basis Set ◽  
Monoclinic Space Group

Synthesis of 3-(1-((benzoyloxy)imino)ethyl)-2H-chromen-2-ones (1-5) was accomplished and it was characterized experimentally using various analytical techniques. Computational studies have been carried out for all compounds 1-5 using B3LYP method with 6-311++G(d,p) basis set. The optimized structural features viz. bond lengths, bond angles, and dihedral angles are compared with their single-crystal X-ray diffraction results of compound 1 (Crystal data for C18H13NO4 (M = 307.29 g/mol): Monoclinic, space group P21/c (no. 14), a = 11.399(5) Å, b = 5.876(5) Å, c = 21.859(5) Å, β = 91.060(5)°, V = 1463.9(14) Å3, Z = 4, T = 293(2) K, μ(MoKα) = 0.100 mm-1, Dcalc = 1.394 g/cm3, 13555 reflections measured (3.58° ≤ 2Θ ≤ 56.98°), 3669 unique (Rint = 0.0235) which were used in all calculations. The final R1 was 0.0444 (>2sigma(I)) and wR2 was 0.1506 (all data)), which are in good conformity with each other. Normal modes of vibrational frequencies of compounds 1-5 acquired from density-functional theory (DFT) method coincided with the experimental ones. The 1H and 13C chemical shifts of compounds 1-5 have been calculated by GIAO method and the results have been compared with the experimental ones. The first-order hyperpolarizability and their related properties of the novel molecules 1-5 are calculated computationally. The other parameters like natural bond orbital, zero-point vibrational energy, EHOMO, ELUMO, heat capacity and entropy have also been discussed.

Interatomic Potential and Thermodynamic Property of Diatomic Uranium

2012 ◽  
Vol 550-553 ◽  
pp. 2810-2813 ◽  
Author(s):  
Xiu Lin Zeng ◽  
Xue Hai Ju ◽  
Si Yu Xu
Keyword(s):  
Density Functional ◽  
Vibrational Energy ◽  
Interatomic Potential ◽  
Zero Point ◽  
Dft Method ◽  
Basis Set ◽  
Functional Theory ◽  
Lennard Jones ◽  
Anharmonicity Constant ◽  
The Relationship

Potential energy scan for U2 was performed by density functional theory (DFT) method at the B3LYP level in combination with the (ECP80MWB_AVQZ + 2f) basis set. The dissociation energy of U2, after being corrected for the zero-point vibrational energy, is 2.482 eV, which is in good agreement with the experiment. The calculated energy was fit to the typical potential functions of Morse, Lennard-Jones (L-J) and Rydberg. Both the Morse and Rydberg functions are good representatives of the potentials, but the Lennard-Jones function is not. The anharmonicity constant is very small. The anharmonic frequency is 113.99 cm–1. Thermodynamic properties of entropy and heat capacity at 298.2 K – 1500 K were calculated by using DFT-B3LYP computational results and Morse parameters, respectively. The relationship between entropy and temperature was established.

A density functional approach toward structural features and properties of C20…N2X2 (X = H, F, Cl, Br, Me) molecules

2014 ◽  
Vol 13 (04) ◽  
pp. 1450023 ◽  
Author(s):  
Reza Ghiasi ◽  
Morteza Zaman Fashami ◽  
Amir Hossein Hakimioun
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Geometry Optimization ◽  
Structural Features ◽  
Nbo Analysis ◽  
Basis Set ◽  
Basis Sets ◽  
Basis Set Superposition Error ◽  
Homo And Lumo ◽  
Lowest Unoccupied Molecular Orbitals

In this work, the interaction of C 20 with N 2 X 2 ( X = H , F , Cl , Br , Me ) molecules has been explored using the B3LYP, M062x methods and 6-311G(d,p) and 6-311+G(d,p) basis sets. The interaction energies (IEs) obtained with standard method were corrected by basis set superposition error (BSSE) during the geometry optimization for all molecules at the same levels of theory. It was found C 20… N 2 H 2 interaction is stronger than the interaction of other N 2 X 2 ( X = F , Cl , Br , Me ) with C 20. Highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO, respectively) levels are illustrated by density of states spectra (DOS). The nucleus-independent chemical shifts (NICSs) confirm that C 20… N 2 X 2 molecules exhibit aromatic characteristics. Geometries obtained from DFT calculations were used to perform NBO analysis. Also, 14 N NQR parameters of the C 20… N 2 X 2 molecules are predicted.

scholarly journals Synthesis, Spectroscopic Investigation and Computational Studies of 2-Formyl-4-(Phenyldiazenyl)Phenyl Methyl Carbonate and 4-((4-Chlorophenyl)Diazenyl)-2-Formylphenyl Methyl Carbonate

2016 ◽  
Vol 66 ◽  
pp. 38-70 ◽  
Author(s):  
A. Arokiasamy ◽  
G. Manikandan ◽  
V. Thanikachalam ◽  
K. Gokula Krishnan
Keyword(s):  
Total Energy ◽  
Density Functional ◽  
Vibrational Energy ◽  
Zero Point ◽  
Basis Set ◽  
Stable Configuration ◽  
Vibrational Assignments ◽  
Computational Optimization ◽  
Methyl Carbonate ◽  
Surface Scan

Two new compounds namely 2-formyl-4-(phenyldiazenyl)phenyl methyl carbonate (FPMC) and 4-((4-chlorophenyl) diazenyl)-2-formylphenyl methyl carbonate (CFPMC) have been synthesized and have characterized using FT-IR, FT-Raman,1H and13C NMR techniques. Computational optimization studies have been carried out using Hatree–Fock (HF) and Density Functional Theory (DFT–B3LYP) methods with 6–31+G(d, p) basis set ofGaussian 09Wsoftware. The stable configuration of the title compounds were achieved theoretically by potential energy surface scan analysis. The complete vibrational assignments were performed on the basis of total energy distribution (TED) and natural bonding orbital (NBO) have been studied. Various parameters such as EHOMO, ELUMO,total energy, dipole moment, polarizability, first order hyperpolarizability, zero–point vibrational energy as well as thermal properties were analyzed and reported for the title compounds.

scholarly journals DFT study of new organic materials based on PEDOT and 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzanamine

2021 ◽  
Author(s):  
Côme Damien Désiré Mveme ◽  
Fridolin Tchangnwa Nya ◽  
Geh Wilson Ejuh ◽  
Alhadji Malloum ◽  
Jeanet Conradie ◽  
...  
Keyword(s):  
Organic Solar Cells ◽  
Density Functional ◽  
Vibrational Energy ◽  
Zero Point ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
Light Emitting ◽  
The Density Functional Theory ◽  
Zero Point Vibrational Energy

Abstract In the present study, we theoretically determine the optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of new materials from the conjugated polymer poly (3,4-ethylenedioxythiophene) (PEDOT) doped with halogens (Fluorine and Chlorine) combined with the organic semiconductor 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzamine (DATVB). The molecular geometry of the ground state, the optoelectronics and electronics parameters have been calculated by combining the 6-311++G (d, p) basis set with functionals of the density functional theory (DFT). The functionals B3LYP and the CAM-B3LYP have been used for NLO parameters. The energy gaps obtains for all the compounds are less than 3.0 eV. These results clearly show that PEDOT and its derivatives can be considerated as good semiconductors. They can be tested for use in the manufacture of organic solar cells (OSC) and organic light emitting diodes (OLED). The first order hyperpolarisabilities of these PEDOT hybrid compounds are much higher than those of the reference compound for NLO applications, namely para-nitroaniline (p-NA), which opens up a new field of application of PEDOT in NLO devices. The thermodynamic parameters such as the zero point vibrational energy (ZPVE), the enthalpy (H), the heat capacity at constant volume (Cv), the entropy (S) and the free energy (G) have been calculated and reported herein.

DENSITY FUNCTIONAL THEORY STUDY OF THE INTERACTION BETWEEN 3-NITRO-1,2,4-TRIAZOLE-5-ONE AND WATER

2005 ◽  
Vol 04 (03) ◽  
pp. 849-856 ◽  
Author(s):  
GUO-YONG FANG ◽  
LI-NA XU ◽  
XIN-GEN HU ◽  
XIN-HUA LI ◽  
HE-MING XIAO ◽  
...  
Keyword(s):  
Intermolecular Interaction ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Zero Point ◽  
Dft Method ◽  
Basis Set ◽  
Statistical Thermodynamic ◽  
Intermolecular Interaction Energy ◽  
Point Energy ◽  
Basis Set Superposition Error

Three fully optimized geometries of 3-nitro-1,2,4-triazol-5-one (NTO)-H2O complexes have been obtained with density function theory (DFT) method at the B3LYP/6-311++G** level. The intermolecular interaction energy is calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction of the NTO–H2O complexes is -30.14 KJ/mol. Electrons in complex systems transfer from H2O to NTO . The strong hydrogen bonds contribute to the interaction energies dominantly. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. Based on the vibrational analysis, the changes of thermodynamic properties from the monomer to complexes with the temperature ranging from 200 K to 800 K have been obtained using the statistical thermodynamic method. It is found that three NTO –water complexes can be produced spontaneously from NTO and H2O at lower temperature.

scholarly journals Geometry, and Normal Modes of Vibration (3N-6) for Di and Tetra-Rings Layer (6, 0) Linear (Zigzag) SWCNTs; A DFT Treatment

2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0726
Author(s):  
Kubba Et al.
Keyword(s):  
Density Functional ◽  
Point Group ◽  
Normal Modes ◽  
Dft Method ◽  
Basis Set ◽  
Single Wall Carbon Nanotubes ◽  
Equilibrium Geometry ◽  
Vibration Frequencies ◽  
Bending Vibrations ◽  
Modes Of Vibration

            Density Functional Theory (DFT) method of the type (B3LYP) and a Gaussian basis set (6-311G) were applied for calculating the vibration frequencies and absorption intensities for normal coordinates (3N-6) at the equilibrium geometry of the Di and Tetra-rings layer (6, 0) zigzag single wall carbon nanotubes (SWCNTs) by using Gaussian-09 program. Both were found to have the same symmetry of D6d point group with C--C bond alternation in all tube rings (for axial bonds, which are the vertical C--Ca bonds in rings layer and for circumferential bonds C—Cc in the outer and mid rings bonds). Assignments of the modes of vibration IR active and inactive vibration frequencies (symmetric and asymmetric modes) based on the image modes applied by the Gaussian 09 display. The whole relations for the vibration modes were also done including nCH stretching, nC--C stretching, δCH, δring (δC--C--C) deformation in plane of the molecule) and gCH, gring (gC--C--C) deformation out of plane of the molecule. The assignment also included modes of puckering, breathing and clock-anticlockwise bending vibrations.

scholarly journals Intramolecular hydroxycarbene C–H-insertion: The curious case of (o-methoxyphenyl)hydroxycarbene

2010 ◽  
Vol 6 ◽  
pp. 1061-1069 ◽  
Author(s):  
Dennis Gerbig ◽  
David Ley ◽  
Hans Peter Reisenauer ◽  
Peter R Schreiner
Keyword(s):  
Density Functional ◽  
Vibrational Energy ◽  
Reaction Pathway ◽  
High Vacuum ◽  
Glyoxylic Acid ◽  
Zero Point ◽  
Basis Set ◽  
Reaction Field ◽  
Insertion Product ◽  
Correlation Consistent

The first C–H insertion of a hydroxycarbene species in the gas phase has been observed experimentally by means of high vacuum flash pyrolysis (HVFP) and subsequent matrix isolation: (o-Methoxyphenyl)glyoxylic acid gives non-isolable (o-methoxyphenyl)hydroxycarbene upon pyrolysis at 600 °C, which rapidly inserts into the methyl C–H bond. The insertion product, 2,3-dihydrobenzofuran-3-ol, was trapped in an excess of Ar at 11 K and characterized by infrared spectroscopy. The insertion process kinetically outruns the alternative [1,2]H-tunneling reaction to o-anisaldehyde, a type of reaction observed for other hydroxycarbenes. Traces of the dehydration product, benzo[b]furan, were also detected. The potential energy hypersurface including the insertion and hydrogen migration processes was computed at the all-electron coupled-cluster level of theory encompassing single and double substitutions and perturbatively included triple excitations [AE-CCSD(T)] in conjunction with a correlation-consistent double-ζ basis set (cc-pVDZ) by utilizing density functional theory (DFT) optimized geometries (M06-2X/cc-pVDZ) with zero-point vibrational energy (ZPVE) corrections. Exchange of the methoxy for a trifluoromethoxy group successfully prevents insertion and (o-trifluoromethoxy)benzaldehyde is produced instead; however, the carbene cannot be observed under these conditions. Thermal decomposition of (o-methoxyphenyl)glyoxylic acid in refluxing xylenes does not give the insertion product but yields o-anisaldehyde. This unanticipated outcome can be rationalized by protonation of the hydroxycarbene intermediate leading to the tautomeric formyl group. Thermochemical computations at M06-2X/cc-pVDZ in conjunction with a self-consistent solvent reaction field model support this suggested reaction pathway.

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

scholarly journals Benchmarking the Fluxional Processes of Organometallic Piano-Stool Complexes

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2310
Author(s):  
Nathan C. Frey ◽  
Eric Van Dornshuld ◽  
Charles Edwin Webster
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Chemical Shifts ◽  
Transition States ◽  
Electronic Energy ◽  
Basis Set ◽  
Composite Approach ◽  
Temperature Regimes ◽  
Correlation Consistent Composite Approach ◽  
Correlation Consistent

The correlation consistent Composite Approach for transition metals (ccCA-TM) and density functional theory (DFT) computations have been applied to investigate the fluxional mechanisms of cyclooctatetraene tricarbonyl chromium ((COT)Cr(CO)3) and 1,3,5,7-tetramethylcyclooctatetraene tricarbonyl chromium, molybdenum, and tungsten ((TMCOT)M(CO)3 (M = Cr, Mo, and W)) complexes. The geometries of (COT)Cr(CO)3 were fully characterized with the PBEPBE, PBE0, B3LYP, and B97-1 functionals with various basis set/ECP combinations, while all investigated (TMCOT)M(CO)3 complexes were fully characterized with the PBEPBE, PBE0, and B3LYP methods. The energetics of the fluxional dynamics of (COT)Cr(CO)3 were examined using the correlation consistent Composite Approach for transition metals (ccCA-TM) to provide reliable energy benchmarks for corresponding DFT results. The PBE0/BS1 results are in semiquantitative agreement with the ccCA-TM results. Various transition states were identified for the fluxional processes of (COT)Cr(CO)3. The PBEPBE/BS1 energetics indicate that the 1,2-shift is the lowest energy fluxional process, while the B3LYP/BS1 energetics (where BS1 = H, C, O: 6-31G(d′); M: mod-LANL2DZ(f)-ECP) indicate the 1,3-shift having a lower electronic energy of activation than the 1,2-shift by 2.9 kcal mol−1. Notably, PBE0/BS1 describes the (CO)3 rotation to be the lowest energy process, followed by the 1,3-shift. Six transition states have been identified in the fluxional processes of each of the (TMCOT)M(CO)3 complexes (except for (TMCOT)W(CO)3), two of which are 1,2-shift transition states. The lowest-energy fluxional process of each (TMCOT)M(CO)3 complex (computed with the PBE0 functional) has a ΔG‡ of 12.6, 12.8, and 13.2 kcal mol−1 for Cr, Mo, and W complexes, respectively. Good agreement was observed between the experimental and computed 1H-NMR and 13C-NMR chemical shifts for (TMCOT)Cr(CO)3 and (TMCOT)Mo(CO)3 at three different temperature regimes, with coalescence of chemically equivalent groups at higher temperatures.

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