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Density functional theory

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Full-Text Articles in Chemistry

Bromination And Conversion Of Tetrahydro-1h-Indene To Bisoxirane With A New Approach: Synthesis, Structural Characterization By Spectroscopic And Theoretical Methods, And Biological Analysis Supported By Dft And Docking, Raşi̇t Fi̇kret Yilmaz, Sultan Erkan, Sali̇h Ökten, Ahmet Tutar, Ertan Şahi̇n Dec 2023

Bromination And Conversion Of Tetrahydro-1h-Indene To Bisoxirane With A New Approach: Synthesis, Structural Characterization By Spectroscopic And Theoretical Methods, And Biological Analysis Supported By Dft And Docking, Raşi̇t Fi̇kret Yilmaz, Sultan Erkan, Sali̇h Ökten, Ahmet Tutar, Ertan Şahi̇n

Turkish Journal of Chemistry

In this study, a new method for synthesizing diepoxides is proposed. Tetrahydroindene 1 was brominated with NBS in the presence of LiClO4 and acetic acid, resulting in the formation of dibromodiacetate derivatives 2 and 3. Treatment of compounds 2 and 3 with NaOH in methanol produced a mixture of diepoxides 4 and 5. Additionally, direct bromination of tetrahydro-1H-indene yielded tetrabromo octahydroindene isomers 6 and 7. The structures of the compounds were characterized using spectroscopic techniques such as 1H NMR, 13C NMR, APT, COSY, and XRD. The new method provides an easy and selective route to access epoxides for the synthesis …


Electronic Structures And Dielectric Function Of (5, 5) Cnt-C2h4o System: A First-Principles Study On The Detection Capability Of Cnt For Gas Sensing Applications, Alvanh Alem Pido, Art Anthony Munio Aug 2023

Electronic Structures And Dielectric Function Of (5, 5) Cnt-C2h4o System: A First-Principles Study On The Detection Capability Of Cnt For Gas Sensing Applications, Alvanh Alem Pido, Art Anthony Munio

Turkish Journal of Chemistry

Carbon nanotubes (CNTs) are known to have a wide range of applications in various fields of discipline. In this research, the ability of metallic armchair (5, 5) CNT to detect acetaldehyde (C2 H4 O) was investigated using first-principles density functional theory (DFT) as implemented in Quantum ESPRESSO with the Generalized Gradient Approximation (GGA). Accordingly, it was found that C2 H4 O preserved the metallic behavior of the CNT. However, some bands are found to have overlapped in both the valence and conduction regions of the electronic structures of the resulting system that are mainly caused by the p orbitals of …


Dft / Tddft Insights Into Excited State Intra-Molecular Hydrogen Atom Transfer Mechanism In Liqcoumarin: An Efp1 Study, Kandigowda Jagadeesha, Yelechakanahally Lingaraju Ramu, Mariyappa Ramegowda Jan 2022

Dft / Tddft Insights Into Excited State Intra-Molecular Hydrogen Atom Transfer Mechanism In Liqcoumarin: An Efp1 Study, Kandigowda Jagadeesha, Yelechakanahally Lingaraju Ramu, Mariyappa Ramegowda

Turkish Journal of Chemistry

The theoretical calculations were carried out on Liqcoumarin (LC) and its water complex LC+(H20)4-[LCH] at the ground (S0) / first excited states (S1) by employing density functional theory (DFT) / state specific time-dependent density functional theory (SS-TDDFT). In LC and LCH, there is an intra-molecular hydrogen bond between hydroxyl group and acetyl group along with four inter-molecular hydrogen bonds in the hydrated molecule. The computational studies of molecular structural parameters, electrostatic potential, NBO analysis, molecular orbital's, and UV-Vis spectra of both molecules under polar solvents were explored by B3LYP / 6-31G (d,p) / PCM / EFP1 method. The intra-molecular hydrogen …


Combined Computational And Experimental Studies On Cysteine-Sulfadiazine Adduct Formation, Nursel Açar Selçuki̇, Emi̇ne Coşkun, Ender Bi̇çer Jan 2020

Combined Computational And Experimental Studies On Cysteine-Sulfadiazine Adduct Formation, Nursel Açar Selçuki̇, Emi̇ne Coşkun, Ender Bi̇çer

Turkish Journal of Chemistry

The electrochemical characterization of sulfadiazine-cysteine (SD-CYS) adduct formation was performed in phosphatebuffer(pH7)onthebasisofvoltammetriccurrentandpeakpotentialmeasurements. Duetotheassociationof cysteine with sulfadiazine, the reduction peak currents of mercuric and mercurous cysteine thiolates decreased and their peak potentials simultaneously shifted to less negative potentials. By using the current changes of mercurous cysteine thiolate, it was determined that cysteine and sulfadiazine are associated with a 1:1 stoichiometry with a conditional association constant of 1.99 ×10$^{4}$ M$^{-1}$. In addition to experimental studies, a computational approach was carried out to study the geometrical parameters, electron densities, and UV-Vis absorption spectra of sulfadiazine and SDCYS adduct in water. Calculated (B3LYP/6-311++G(d,p) level) …


Design, Synthesis, And Spasmolytic Activity Of Thiophene-Based Derivatives Via Suzukicross-Coupling Reaction Of 5-Bromothiophene-2-Carboxylic Acid: Their Structural Andcomputational Studies, Nasir Rasool, Hafiz Mansoor Ikram, Ammara Rashid, Nazia Afzal, Muhammad Ali Hashmi, Muhammad Naeem Khan, Ayesha Khan, Imran Imran, Hafiz Muhammad Abdur Rahman, Syed Adnan Ali Shah Jan 2020

Design, Synthesis, And Spasmolytic Activity Of Thiophene-Based Derivatives Via Suzukicross-Coupling Reaction Of 5-Bromothiophene-2-Carboxylic Acid: Their Structural Andcomputational Studies, Nasir Rasool, Hafiz Mansoor Ikram, Ammara Rashid, Nazia Afzal, Muhammad Ali Hashmi, Muhammad Naeem Khan, Ayesha Khan, Imran Imran, Hafiz Muhammad Abdur Rahman, Syed Adnan Ali Shah

Turkish Journal of Chemistry

In the current research work, a facile synthesis of a series of novel thiophene-based derivatives of 5-bromothiophene-2- carboxylic acid (1) have been synthesized. All analogs (5a-5e, 10a-10f) were obtained from the coupling reaction of 5-bromothiophene- 2-carboxylic acid (1) and different arylboronic acids with moderate-to-good yields under controlled and optimal conditions. The structures of the newly synthesized compounds were characterized through spectral analysis and their spasmolytic activity, and most of the compounds exhibited potentially good spasmolytic effect. Among the synthesized analogs, compound phenethyl 5-(3,4-dichlorophenyl)thiophene-2-carboxylate (10d) particular showed an excellent spasmolytic effect with an EC$_{50}$ value of 1.26. All of the compounds …


Density Functional Theory-Supported Studies Of Structural And Electronic Properties Of Substituted-Phenol Derivatives Synthesized By Efficient O- Or C-Arylation Via Chan--Lam Or Suzuki Cross-Coupling Reactions, Hafiz Mansoor Ikram, Nasir Rasool, Muhammad Ali Hashmi, Muhammad Arfan Anjum, Kulsoom Ghulam Ali, Muhammad Zubair, Gulraiz Ahmad, Tariq Mahmood Jan 2019

Density Functional Theory-Supported Studies Of Structural And Electronic Properties Of Substituted-Phenol Derivatives Synthesized By Efficient O- Or C-Arylation Via Chan--Lam Or Suzuki Cross-Coupling Reactions, Hafiz Mansoor Ikram, Nasir Rasool, Muhammad Ali Hashmi, Muhammad Arfan Anjum, Kulsoom Ghulam Ali, Muhammad Zubair, Gulraiz Ahmad, Tariq Mahmood

Turkish Journal of Chemistry

The present study reports the efficient synthesis and computational studies of the structural and electronic properties of some interesting substituted phenol derivatives. Efficient and versatile procedures to synthesize a series of diaryl ether derivatives (2a-2c, 4a-4h) and bis-arylated products (5a-5c) are described. In this manuscript, using the commercially available starting material 1 and 3, a 1-step approach was developed by means of Cu(II)-mediated Chan-Lam and Pd-catalyzed Suzuki cross-coupling reactions to synthesize diaryl ether and bis-arylated products with moderate to good yields. The starting substrates, 2-bromo-4-methylphenol 1 or 2,4-dibromophenol 3, were both treated with several arylboronic acids, which led to the …


Coupling Ferrocene To Brominated Tetraazaporphyrin: Exploring An Alternative Synthetic Pathway For Preparation Of Ferrocene-Containing Tetraazaporphyrins, Victor N. Nemykin, Elena A. Makarova, Nathan R. Erickson, Pavlo V. Solntsev Jan 2014

Coupling Ferrocene To Brominated Tetraazaporphyrin: Exploring An Alternative Synthetic Pathway For Preparation Of Ferrocene-Containing Tetraazaporphyrins, Victor N. Nemykin, Elena A. Makarova, Nathan R. Erickson, Pavlo V. Solntsev

Turkish Journal of Chemistry

A Castro--Stephens coupling reaction between metal-free 3(2),8(7)-dibromo- 2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin and (ferrocenylethynyl)copper resulted in the formation of copper 2(3),7(8),12(13), 17(18)-tetra-tert-butyl-3(2), 8(7)-di(ferrocenylethynyl)-5,10,15,20-tetraazaporphyrin and copper 2(3),7(8),12(13),17(18)-tetra-tert-butyl-3(2)-ferrocenylethynyl-5, 10,15,20-tetraazaporphyrin, which were separated in the form of 2 positional isomers along with copper 3(2)-bromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin and copper 2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin. A similar reaction with metal-free 3(2),8(7),13(12), 18(17)-tetrabromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin resulted in only a trace amount of 3(2),8(7),13(12)-tribromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-18(17) -ferrocenylethynyl-5,10,15,20-tetraazaporphyrin, while no products with larger number of organometallic substituents were observed. Direct coupling between ferrocenelithium and 3(2),8(7)-dibromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin resulted in a debromination reaction accompanied by very minor dimerization of the tetraazaporphyrin core, which was explained based on the steric properties of the parent tetraazaporphyrin. The …


A Dft Study On The Structural And Optical Properties And Cation Selectivities Of Some Metal-Coumarin-Crown Ether Complexes, Emi̇ne Esra Kasapbaşi, Mi̇ne Yurtsever Jan 2012

A Dft Study On The Structural And Optical Properties And Cation Selectivities Of Some Metal-Coumarin-Crown Ether Complexes, Emi̇ne Esra Kasapbaşi, Mi̇ne Yurtsever

Turkish Journal of Chemistry

Macrocyclic ethers are well-known molecules because of their high cation-binding capacities. They form stable complexes with alkaline and soil alkaline metals through strong oxygen bridges in solution. For enhanced optical properties, a new series of crown ethers was synthesized with a coumarin ring fused to it. The effects of the position of the coumarin ring, the type of the substituent on the coumarin ring, and the size of the crown on the optical properties of the material were studied according to the density functional theory (DFT) method at the B3LYP/6-31g(d) level of theory in the gas phase as well as …


Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal Jan 2007

Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal

Turkish Journal of Chemistry

C-H bond activation was studied by use of density functional theory (DFT) and ONIOM calculations as implemented in Gaussian 2003 at the B3LYP level utilising 6-31G* as the basis set for Si, Al, and Fe atoms and 3-21G** as the basis set for O and H atoms. Relative energy profiles were determined for pure silica modeled by a Si_7O_{21} cluster and Fe and Al doped silica clusters via coordinate driving calculations. The activation barriers for C-H bond activation of methane and ethane decrease with the substitution of Fe on the silica surface, which theoretically demonstrates a favorable effect of Fe …