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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
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
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
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 …
Dft Study Of NiM@Pt1AuN-M-1 (N=19, 38, 55, 79; M = 1, 6, 13, 19) Core-Shell Orr Catalyst, Wen-Jie Li, Dong-Xu Tian, Hong Du, Xi-Qiang Yan
Dft Study Of NiM@Pt1AuN-M-1 (N=19, 38, 55, 79; M = 1, 6, 13, 19) Core-Shell Orr Catalyst, Wen-Jie Li, Dong-Xu Tian, Hong Du, Xi-Qiang Yan
Journal of Electrochemistry
The slow kinetics of oxygen reduction reaction (ORR) limits the performance of low temperature fuel cells. Thus, it needs to design effective catalysts with low cost. Core-shell clusters (CSNCs) show promising activity because of their size-dependent geometric and electronic effects. The ORR activity trend of Nim@Pt1Aun-m-1(n = 19, 38, 55, 79; m = 1, 6, 13, 19) was studied using the GGA-PBE-PAW methods. The adsorption configurations of *O, *OH and *OOH were optimized and the reaction free energies of four proton electron (H+ + e-) transfer steps were calculated. Using …
Theoretical Study On Electrical Properties Of Molecular Junctions Of Viologen Derivatives, Zhuan-Yun Cai, Jia Liu, Si-Yuan Guan, De-Yin Wu, Zhong-Qun Tian
Theoretical Study On Electrical Properties Of Molecular Junctions Of Viologen Derivatives, Zhuan-Yun Cai, Jia Liu, Si-Yuan Guan, De-Yin Wu, Zhong-Qun Tian
Journal of Electrochemistry
In this paper, the electrical properties of molecular junctions formed N,N′-bis(4-thioalkyl)-4,4′-bipyridinium (viologen) moiety between two gold (Au) electrodes have been investigated by combining density functional theory and non-equilibrium Green’s functional approach. To modulate the viologen molecule to be a cation with one and two positive charges (V+ and V2+), we introduce one and two trifluoroacetic acid ions (TFA-) around the molecule, respectively. The valence states of V+ and V2+ are confirmed by checking Mulliken and NBO charges. Then the relationship between molecular conductance and electronic structures of the neutral state V, the radical state V+ and dication …
Combined Computational And Experimental Studies On Cysteine-Sulfadiazine Adduct Formation, Nursel Açar Selçuki̇, Emi̇ne Coşkun, Ender Bi̇çer
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
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 …
The Importance Of Properly Modeling The Hydrogen Bond In Histidine, Falonne M. Tchodimo, Guoquan Zhou, Hua-Jun Fan
The Importance Of Properly Modeling The Hydrogen Bond In Histidine, Falonne M. Tchodimo, Guoquan Zhou, Hua-Jun Fan
Pursue: Undergraduate Research Journal
The hydrogen bond plays a vital role in many reactions. This study is to investigate the effect of different hydrogen bonding modes, such as single and double hydrogen bonds, via the quantum mechanic (QM) methods. Four histidine models (A, B, C, and D) with different numbers of intra-molecular hydrogen bonds were studied. The QM model results indicate that the double hydrogen bond is plausible and has a more stable geometry. However, this study suggests that the data from QM methods require further evaluation with solvation models to produce an even better energy profile.
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
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 …
Dft Study Of Water Assisted Hydrogen Dissociation On Gold Nanoparticles, Jia-Li Chen, Xia-Guang Zhang, De-Yin Wu, Zhong-Qun Tian
Dft Study Of Water Assisted Hydrogen Dissociation On Gold Nanoparticles, Jia-Li Chen, Xia-Guang Zhang, De-Yin Wu, Zhong-Qun Tian
Journal of Electrochemistry
The gold nanoparticles (GNPs) show special activity toward hydrogen (H2) dissociation, comparing with bulk gold. Such activity is significantly affected by the existence of water. To inspect the influence of water on GNPs catalyzed H2 dissociation, we carried out density functional theory (DFT) calculations along the reaction paths for water clusters (H2O)m (m = 1, 2, 3, 7) assisted H2 dissociation on gold clusters (Aunδ, n = 3 ~ 5; δ = 0, 1). Our calculated results show that water benefits to the H2 dissociation. The dissociation mechanism varies …
Surface Chemical Properties Of Mo2C, W2C, Mo2N And W2N Probed With Co, Co2And O2 Adsorption: A Dft Analysis, Jingyun Ye, Tianyu Zhang, Lingyun Xu, Shuxia Yin, Krishanthi Weerasinghe, Pamela Ubaldo, Ping And Ge Qingfeng He
Surface Chemical Properties Of Mo2C, W2C, Mo2N And W2N Probed With Co, Co2And O2 Adsorption: A Dft Analysis, Jingyun Ye, Tianyu Zhang, Lingyun Xu, Shuxia Yin, Krishanthi Weerasinghe, Pamela Ubaldo, Ping And Ge Qingfeng He
Journal of Electrochemistry
Transition metal carbides and nitrides are attractive materials for electrodes in many electrochemical energy storage and conversion applications. In the present study, we use density functional theory slab calculations to characterize the surface chemical properties of molybdenum (Mo) and tungsten (W) carbides and nitrides, namely, Mo2C, W2C, Mo2N and W2N with the adsorption of CO, CO2 and O2. These probing molecules provide measures of in both acidity/basicity and redox property of for the surfaces of these carbides and nitrides. Our results show that Lewis basic sites were responsible for CO2 …
Green Electrochemical Ozone Production Via Water Splitting: Mechanism Studies, Gregory Gibson, Wenfeng Lin
Green Electrochemical Ozone Production Via Water Splitting: Mechanism Studies, Gregory Gibson, Wenfeng Lin
Journal of Electrochemistry
The green and energy-efficient water splitting reaction using electrocatalysis for O3 formation provides a very attractive alternative to the conventional energy-intensive cold corona discharge (CCD) method. Among a large number of electrocatalysts explored for the electrochemical ozone production, β-PbO2 and SnO2-based catalysts have proven to be the most efficient ones at room temperature. In this study Density Functional Theory (DFT) calculations have been employed to investigate the possible mechanisms of ozone formation over these two types of catalysts. For both the β-PbO2 and Ni/Sb-SnO2 (nickel and antimony doped tin oxide) catalysts the …
Aligning Electronic Energy Levels On The Anatase Tio2(101) Surface, Jun-Jie Zhao, Jun Cheng
Aligning Electronic Energy Levels On The Anatase Tio2(101) Surface, Jun-Jie Zhao, Jun Cheng
Journal of Electrochemistry
As one of the most commonly-used materials for photocatalysis and solar energy conversion, titanium dioxide (TiO2) has been extensively studied for more than 40 years. Its photoelectrochemical activity crucially depends on the band positions at the interface. In this work, the valence band maximum (VBM) and conduction band minimum (CBM) of a model TiO2 surface are computed using the standard work function method at the level of Perdew-Burke-Ernzerhof (PBE) density functional, which are then converted to the scale of the standard hydrogen electrode (SHE) by subtracting the absolute SHE potential. Comparing with the rutile TiO2(110) …
Density Functional Theory Study On The Structures Of Solvent-Ion In The Electrolyte Of Lithium Ion Battery, Li-Dan Xing, Ru Yang, Xian-Wen Tang, Wen-Na Huang, Qi-Feng Liu, Qi-Peng Yu, Wei-Shan Li
Density Functional Theory Study On The Structures Of Solvent-Ion In The Electrolyte Of Lithium Ion Battery, Li-Dan Xing, Ru Yang, Xian-Wen Tang, Wen-Na Huang, Qi-Feng Liu, Qi-Peng Yu, Wei-Shan Li
Journal of Electrochemistry
In this work, the possible structures of solvent-ion complex, resulting from the electrostatic interaction in the propylene carbonate (PC) base electrolyte of lithium ion battery, have been investigated using the density functional theory. The calculated results show that the structure of solvent-ion complex depends on the solvent number. In the PC base electrolyte, maximum number of PC solvents that coexist in the Li+-solvent sheath is four. Additionally, the salt anion exists in a complex with the positively charged alkyl group of PC rather than in a free state. The calculated results give a good explanation to the reported …
Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei
Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei
Journal of Electrochemistry
In this review, we focus on achievements in electro-catalysis based on the density function theory study. The relationships among the electrode potential, electronic structure of catalysts and electro-catalytic activity are summarized in three parts: the adsorption and desorption of species, electron transfer, and stability of catalysts. The electrode potential and the electronic structure (d-band center or Fermi (HOMO) energy) of catalysts significantly influence the formation, adsorption and desorption of surface species on electrode. The electro-catalytic activity can be improved by modulating the electrode potential and electronic structure of catalysts.
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
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
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
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 …