scholarly journals Tautomerism in Flindersine - A DFT Treatment

2020 ◽  
pp. 89-104
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Transition State ◽  
Natural Product ◽  
Quantum Chemical ◽  
Density Functional ◽  
Functional Theory ◽  
Valence Tautomerism ◽  
Plant Kingdom

Flindersine is a natural product of plant kingdom. Its structure contains a lactam group which could undergo 1,3-type proton tautomerism. It also has an embedded pyran moiety which might show valence tautomerism. Presently, those tautomers are investigated within the restrictions of density functional theory at the level of B3LYP/6-311++G(d,p). Certain quantum chemical output has been collected compared and discussed. Also the possibility of valence tautomerism has been searched by proposing two transition state paths.

scholarly journals Tautomerism in Fuscin - A DFT Treatment

2020 ◽  
pp. 243-259
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Natural Product ◽  
Quantum Chemical ◽  
Spectral Properties ◽  
Density Functional ◽  
Functional Theory ◽  
Valence Tautomerism ◽  
Valence Tautomer ◽  
Benzenoid Ring ◽  
Stable Structures

Fuscin, a natural product having various functionalities, may exhibit 1,3- and 1,5-proton tautomerism, as well as valence tautomerism via its 1,5-proton tautomer. All those possible forms are investigated within the realm of density functional theory with the constraints of B3LYP/6-311+G(d,p) level. NICS(0) calculation has been performed for the valence tautomer which possesses a benzenoid ring. The tautomers are found to be stable structures but the valence tautomer is the least likely one. Some QSAR, quantum chemical and spectral properties are obtained and discussed.

scholarly journals Some Curcumin Isomers and Their Enol Tautomers - A DFT Treatment

2020 ◽  
pp. 183-197
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Natural Product ◽  
Spectral Data ◽  
Quantum Chemical ◽  
Density Functional ◽  
Health Benefits ◽  
Functional Theory

Curcumin is a well known natural product having some health benefits. In the present study, within the constraints of density functional theory (at the level of B3LYP/6-31G(d,p)), some configurational isomers of curcumin and their keto-enol tautomers have been investigated. Some quantum chemical, QSAR and spectral data of them have been obtained and discussed.

scholarly journals Homolytic C-NO2 Bond Cleavage in Diaminodinitroethylene Isomers - A DFT Treatment

2020 ◽  
pp. 115-136
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Transition State ◽  
Quantum Chemical ◽  
Density Functional ◽  
Bond Cleavage ◽  
Chemical Properties ◽  
Bond Rupture ◽  
Homolytic Cleavage ◽  
Functional Theory ◽  
The One

Diaminodinitroethylene (DADNE) has three isomers including the well known geminal isomer, FOX-7. In the present study, the homolytic cleavage of one of the C-NO2 bonds of these isomers has been considered within the constraints of density functional theory at the level of UB3LYP/6-311++G(d,p). Transition states for that type of bond rupture are obtained. Various quantum chemical properties of the parent compounds and the decomposed systems are obtained, compared and discussed. Also the activation energies are calculated. The transition state originating from cis DADNE and the one from the geminal DADNE are found to be the most and least stable ones, respectively among the all.

A density functional theory insight into the structure and reactivity of diphenyltin(IV) derivative of glycylphenylalanine

2016 ◽  
Vol 39 (3-4) ◽  
Author(s):  
Sandeep Pokharia ◽  
Rachana Joshi ◽  
Mamta Pokharia ◽  
Swatantra Kumar Yadav ◽  
Hirdyesh Mishra
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Functional Theory ◽  
Insight Into

AbstractThe quantum-chemical calculations based on density functional theory (DFT) have been performed on the diphenyltin(IV) derivative of glycyl-phenylalanine (H

A novel mechanism of spin-orientation dependence of O2 reactivity from first principles methods

2017 ◽  
Vol 7 (5) ◽  
pp. 1040-1044 ◽  
Author(s):  
M. C. S. Escaño ◽  
H. Kasai
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Transition State ◽  
First Principles ◽  
Density Functional ◽  
Orientation Dependence ◽  
Coupling Mechanism ◽  
Spin Moment ◽  
Spin Orientation ◽  
Functional Theory

A novel mechanism of oxygen reaction on a metal surface beyond the present charge transfer or hybridization mechanism, spin-orientation dependence via a coupling mechanism due to the finite spin moment of O2 at the transition state, is obtained using a combination of spin density functional theory (SDFT) and constrained DFT.

scholarly journals Thermodynamic Parameters of PbTe Crystals: DFT-Calculations

2015 ◽  
Vol 16 (1) ◽  
pp. 28-33
Author(s):  
D. M. Freik ◽  
B. P. Volochanska ◽  
T. O. Parashchuk
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Electronic Structure ◽  
Thermodynamic Parameters ◽  
Quantum Chemical ◽  
Density Functional ◽  
Cubic Phase ◽  
Functional Theory ◽  
Temperature Dependences ◽  
Analytical Expressions

Based on the analysis of the crystal NaCl type and electronic structure of cubic phase CdS crystals the cluster models have been built for calculation of the geometric and thermodynamic parameters. According to density functional theory (DFT) and using the hybrid valence base set B3LYP the temperature dependence of the energy ΔE and the enthalpy ΔH of formation, Gibbs free energy ΔG, entropy ΔS, specific heat at constant volume CV and pressure CP of the crystals have been found. The analytical expressions of the temperature dependences of presented thermodynamic parameters which was approximated from the quantum- chemical calculations data and with using mathematical package Maple 14 have been received.

scholarly journals Quantum Chemical Calculations on Locked Nucleic Acid based Modifications: A Density Functional Theory (DFT) Study

2020 ◽  
Author(s):  
Mallikarjunachari Uppuladinne ◽  
Dikshita Dowerah ◽  
Uddhavesh Sonavane ◽  
Suvendra Kumar Ray ◽  
Ramesh Deka ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nucleic Acid ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Locked Nucleic Acid ◽  
Dft Study ◽  
Functional Theory
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