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 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 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 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

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.

scholarly journals Tautomerism in Pindone – A DFT Study

2019 ◽  
pp. 35-50 ◽  
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Dipole Moment ◽  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Properties ◽  
Dft Study ◽  
Functional Theory ◽  
Local Aromaticity

Pindone is a rodenticide having three keto groups in its structure. Presently, 1,3-type keto-enol tautomerism of pindone has been studied within the constraints of density functional theory at the level of B3LYP/6-311++G(d,p). Various structural and quantum chemical properties of these tautomers have been obtained, compared and discussed. Endocyclic and exocyclic enol forms of pindone are accompanied by dipole moment vectors having opposite directions. The endocyclic enol structure is found to be more stable than the exocyclic enol and pindone. IR and UV-VIS spectra are obtained. NICS(0) values are calculated to visualize the effect of tautomerism on the local aromaticity of the structures considered.

scholarly journals Boron and nitrogen doping in graphene: an experimental and density functional theory (DFT) study

Nano Express ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 010027
Author(s):  
Cantekin Kaykılarlı ◽  
Deniz Uzunsoy ◽  
Ebru Devrim Şam Parmak ◽  
Mehmet Ferdi Fellah ◽  
Özgen Çolak Çakır
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Nitrogen Doping ◽  
Dft Study ◽  
Functional Theory
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