scholarly journals Isomers of (L)-Diiodotyrosine - A DFT Treatise

2021 ◽  
pp. 347-361
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Hydrogen Bonding ◽  
Quantum Chemical ◽  
Density Functional ◽  
Heat Of Formation ◽  
Functional Theory ◽  
Free Energy Of Formation ◽  
Ionic Forms ◽  
Energy Of Formation

(L)-Diiodotyrosine isomers are considered within the realm of density functional theory at the level of B3LYP/6-311+G(d,p). Their zwitter ionic forms are considered as well. All the structures are electronically stable, have exothermic heat of formation and favorable Gibbs free energy of formation values. Within the limitations of the method the zwitter ionic forms are not different from the corresponding parent structures in the vacuum conditions and no hydrogen bonding seems to exist between the NH2 and COOH groups. Some structural, quantum chemical and spectral data have been collected and discussed.

scholarly journals Interaction of Carmustine Tautomers with Adenine - DFT Study

2020 ◽  
pp. 63-76
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Quantum Chemical ◽  
Density Functional ◽  
Equilibrium Concentration ◽  
Dft Study ◽  
Functional Theory ◽  
Dna And Rna ◽  
Free Energy Of Formation ◽  
Energy Of Formation

Carmustine is a chemotherapic substance used in treatment of various cancers. In the present study, within the constraints of density functional theory (B3LYP/6-31++G(d,p)), tautomerism of carmustine has been investigated. It may undergo 1,3-type proton tautomerism, however the obtained data for vacuum conditions indicated that the equilibrium concentration of the enol type tautomer should be low. Afterwards, interactions of those tautomers with adenine, a constituent base of DNA and RNA, have been investigated. The composites (1:1) are electronically stable. Their heat of formations are exothermic and the free energy of formation values are favorable. Some of their calculated properties (structural, physicochemical and quantum chemical) are obtained and discussed.

scholarly journals Interaction of 1,1-Diamino-2,2-Dinitroethylene with Aluminum and Gallium Admixture - DFT Treatment

2020 ◽  
pp. 87-103
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Properties ◽  
Open Shell ◽  
Functional Theory ◽  
Free Energy Of Formation ◽  
Electronic Configurations ◽  
Energy Of Formation

Interaction of 1,1-diamino-2,2-dinitroethylene with nAl+mGa (n,m:1,2) admixture has been investigated within the constraints of density functional theory at the level of UB3LYP/6-311++G(d,p). Various multiplicity states arise for the composites due to the open-shell ground state electronic configurations of Al and Ga atoms. The composites are electronically stable, thermodynamically exothermic and have favorable Gibbs’ free energy of formation values. Various quantum chemical properties have been obtained and discussed. The calculated UV-VIS spectra indicate that some of the composites are infrared absorbing systems beyond 700 nm.

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 Charged Forms of Diacetone Diperoxide - DFT Treatment

2021 ◽  
pp. 53-65
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
Organic Peroxide ◽  
Functional Theory ◽  
Diacetone Diperoxide ◽  
Ionic Forms

Diacetone diperoxide (DADP) is one of the sensitive and powerful organic peroxide explosives like its trimeric analogue TATP. Presently, some ionic forms of it have been investigated within the limitations of density functional theory at the level of UB3LYP/6-311++G(d,p). Various properties (including structural, electronic, spectral and quantum chemical) have been obtained and discussed. The studied mono and dianions having different multiplicity states have been found to be stable but monocation form decomposed.

scholarly journals Some DADNE Originated Cyclic Isomers - A DFT Study

2020 ◽  
pp. 137-153
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Spectral Data ◽  
Quantum Chemical ◽  
Density Functional ◽  
Dft Study ◽  
Functional Theory ◽  
Type Molecule ◽  
Cis And Trans ◽  
Ionic Forms

Diaminodinitroethylene (DADNE) has three constitutional isomers, geminal, cis and trans. The geminal one is the well known FOX-7 explosive. It is a push-pull type molecule. In the present study, within the restrictions of density functional theory at the level of B3LYP/6-311++G(d,p), two cyclic dimeric structures of DADNE are investigated quantum chemically. Also their mono ionic forms have been investigated (unrestricted treatment). All the structures are found to be stable. Various quantum chemical and spectral data are collected computationally and discussed.

scholarly journals Some Ions of TNAZ - A DFT Study

2021 ◽  
pp. 215-228
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
High Energy ◽  
Dft Study ◽  
Thermally Stable ◽  
Functional Theory ◽  
Ionic Forms

TNAZ is a thermally stable high energy explosive molecule. In the present study, some ionic forms of it have been investigated within the limitations of density functional theory at the level of UB3LYP/6-311++G(d,p). Various properties (including structural, electronic, spectral and quantum chemical) are obtained and discussed.

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

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