Theoretical investigation on electronic properties and carrier mobilities of BN-substituted graphyne nanoribbons
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Bing Liang, Hongcun Bai, Yuanhe Huang This paper presents the self-consistent field crystal orbital studies of the BN-substituted graphyne nanoribbons (NRs) based on density functional theory. Two kinds of the substitution are considered: one is that the six-membered rings in the graphyne NRs are replaced by the corresponding BN hexagonal rings; another is the substitution of acetylenic linkages by BN units. The calculations show that all the optimized one-dimensional BN-substituted graphyne NRs still keep plane struc...
Source: Computational and Theoretical Chemistry - July 13, 2017 Category: Chemistry Source Type: research

DFT investigations on the conversion of acetylene to undesired vinyl acetylene during vinyl acetate synthesis
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Minhua Zhang, Xingyu Wu, Xuewei Huang, Bing Yang, Yingzhe Yu Density functional theory was employed to investigate the alternative mechanisms of vinyl acetylene formation on zinc acetate/activated carbon catalyst, aiming to better understand the deactivation behaviour and illustrate the plausible vinyl acetylene formation routes during vinyl acetate synthesis. The structural and energetic properties of relevant species were calculated and discussed in details. Two possible pathways for vinyl acetylene formation were p...
Source: Computational and Theoretical Chemistry - July 8, 2017 Category: Chemistry Source Type: research

Quantum wave packet dynamics of the H+Li2 reaction at state-to-state level of theory
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Ziliang Zhu, Bin Dong, Wang Li The time-dependent wave packet method with a second order split operator is employed to study the state-to-state resolved reaction dynamics of the H+Li2 system. The dynamics properties, such as reaction probability, integral cross-section, differential cross-section and the rovibrational state distribution of the product are fully calculated in the present work. Both forward and backward scattering signals peaked at two extreme angles, indicating that the insert reaction mechanism plays ...
Source: Computational and Theoretical Chemistry - July 7, 2017 Category: Chemistry Source Type: research

The role of intramolecular H-bonds predominant effects in myricetin higher antioxidant activity
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Abolfazl Barzegar Flavonoid antioxidants play essential roles in the prevention of damage caused by free radicals, which is concerned in many chemical and biological processes. The structural electronic properties of myricetin (Myc) and six respective radicals such as total electronic energies, bond dissociation enthalpy magnitudes (BDEs), intramolecular H–bonds strength and charges density distributions have been computed using density functional theory approach with B3P86 level. The important Myc molecular cha...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

Elucidation of the complex deprotonation routes of Changrolin, the antihypertensives LQM-303 and LQM-303b, and their derivatives
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Manuel Alejandro Hernández-Olivares, Agustin Ibarra-Escutia, Gabriela Mendoza-Sarmiento, Alberto Rojas-Hernández, Annia Galano Elucidating the most likely deprotonation routes for polyprotic molecules is crucial in order to know the structures of the species prevailing under specific pH conditions. This is particularly important for molecules with potential applications as medical drugs, since different acid-base species, with the same deprotonation degree, may not interact in the same way with biologica...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

Structure-reactivity relationships of N-hydroxysaccharin analogues as organocatalysts for aerobic oxidation
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Hangen Du, Qianqian Shen, Ling Feng, Lin Fei, Xiatao Zhou, Zuguang Li, Kexian Chen, Kezhi Jiang The structure-reactivity relationships of new N-hydroxysaccharin analogous organocatalysts for aerobic oxidation have been theoretically explored based on the replacements of carbonyl groups in the succinimide ring of N-hydroxyphthalimide and N,N-dihydroxypyromellitimide by sulfinyl or sulfonyl groups. Both sulfinyl and sulfonyl groups largely change catalytic reactivity by altering the planar resonance/conjugation structur...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

The story of the B4H4 molecule told again
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Aristotle Papakondylis, Aristides Mavridis Employing ab initio multireference and coupled-cluster methods along with correlation consistent basis sets we have studied three geometrical isomers of the (hydro)borane B4H4 molecule, namely, the highly symmetric geometrical configuration Td (regular tetrahedron) and two isomers of planar Cs geometries tagged Td(II), Cs(I), and Cs(III), respectively. Mostly for reasons of consistency the species BH(X 1 Σ+, a 3Π), BH2( X ̃ 2 A 1 ), and H2BBH2(D2h, D2d) have also...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

Ab initio investigation of pristine and doped single-walled boron nitride nanotubes as acetone sensor
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Guo-hong Fan, Sheng Zhu, Xiao-kun Li, Ke Ni, Hong Xu The sensor properties of single-walled boron nitride nanotubes (BNNTs) towards acetone are studied by investigating the intermolecular interactions of acetone with a serials of pristine and doped BNNTs. Density-functional theory (DFT) with empirical dispersion corrected is adopted to explore the adsorption properties of acetone on the surface of BNNT. Results show that acetone binds strong to the surface of pristine BNNTs with small diameter and the adsorption energ...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

Time-evolution study of photoinduced charge-transfer in tertiary amine-fluorophore systems
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Demeter Tzeli, Theodoros Mercouris, Giannoula Theodorakopoulos, Ioannis D. Petsalakis Photoinduced charge transfer in a fluorescent sensor of organophosphorus nerve agents is examined by solution of the time dependent Schrödinger equation, under the influence of an external electromagnetic field and employing potential energy curves obtained by density functional theory (DFT) and time dependent DFT (TDDFT) calculations for the ground and the excited states, respectively. The systems of interest here consist of a ...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

Intramolecular CS ⋯OS(C) chalcogen bonds: A theoretical study of the effects of substituents and intermolecular hydrogen bonds
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Yanhua Wang, Yuchen Zhang, Zhijian Xu, Jianying Tong, Wei Teng, Yunxiang Lu According to our search of the Cambridge Structural Database, a huge number of crystal structures involving intramolecular CS⋯OS(C) interactions were extracted. The largest proportion of these interactions in the crystals shows rather good linearity and short interatomic S⋯O distances. Then, intramolecular CS⋯OS(C) interactions in three representative organic molecules, i.e. sulfamethizole, thioindirubin, and thiazolo-pyridinium methide,...
Source: Computational and Theoretical Chemistry - July 5, 2017 Category: Chemistry Source Type: research

First-principles study on photoswitching behavior and negative differential resistance in single molecule junction
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Baoan Bian, Yapeng Zheng, Peipei Yuan, Bin Liao, Wei Chen, Weibao Li, Xiaotong Mo, Huaxiu An, Yuqiang Ding We investigate the electronic transport of a photochromic molecule, a 1,2-dithienyl-1,2-dicyanoethene sandwiched between two Au electrodes using first-principles based on non-equilibrium Green’s function and density functional theory. This molecule can be reversibly transformed between trans and cis state through irradiation. The calculated current of the cis form is larger than the trans form, indicating a...
Source: Computational and Theoretical Chemistry - June 28, 2017 Category: Chemistry Source Type: research

Borophene: A novel boron sheet with a hexagonal vacancy offering high sensitivity for hydrogen cyanide detection
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Akbar Omidvar Elemental boron is electron-deficient and cannot form graphene-like structures. Instead, triangular boron lattices with hexagonal vacancies have been predicted to be stable. Recently, experimental and theoretical studies showed that the B36 sheet has a planar C6V structure with a central hexagonal hole, providing the first experimental evidence for the viability of atom-thin boron sheets with hexagonal vacancies, dubbed borophene. Herein, the sensitivity of the B36 borophene toward HCN molecule is theore...
Source: Computational and Theoretical Chemistry - June 27, 2017 Category: Chemistry Source Type: research

Mechanism of K+, Cs+ ion exchange in nickel ferrocyanide: A density functional theory study
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Hiroto Tachikawa, Kazuko Haga, Kazuo Yamada Since the accident at the Fukushima nuclear power plant, the removal of radioactive cesium ions (137Cs+) from wastewater has become an important topic. Nickel ferrocyanide (Ni-FeCN) is known to adsorb 137Cs+ preferentially from radioactive waste solutions. However, the mechanism underlying the selectivity of Ni-FeCN is not clearly understood. In the present study, the ion selectivity of Ni-FeCN was investigated by means of density functional theory (DFT) calculations to dete...
Source: Computational and Theoretical Chemistry - June 27, 2017 Category: Chemistry Source Type: research

Free radical scavenger properties of metal-fullerenes: C60 and C82 with Cu, Ag and Au (atoms and tetramers)
In this report we present a theoretical study (Density Functional Approximation), focusing on the stability and the free radical scavenger capacity of metal-fullerenes. We also denominate free radical scavenger capacity as antioxidant or antiradical. Two different fullerenes have been considered for this investigation: C60 and C82. Three transition metals were included to form the metal-fullerenes: copper, silver and gold (one atom and a cluster formed with four atoms). We analyzed the free radical scavenger capacity considering two mechanisms: electron transfer (ET) and radical adduct formation (RAF). From this report, it...
Source: Computational and Theoretical Chemistry - June 27, 2017 Category: Chemistry Source Type: research

Study on adsorption and diffusion of lithium on nitrogen doped silicon carbide nanotubes by density functional theory
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Weimei Shi, Chao Lu, Shiqing Yang, Jianguo Deng Spin-unrestricted density functional theory (DFT) calculation was carried out to investigate the adsorption and diffusion of lithium atom on pristine and N-doped silicon carbides (SiCNTs). It is shown that N-doping reduced the structural stability of SiCNTs and narrowed the HOMO-LUMO gaps. Moreover, N-doping enhanced the lithium storage capacity of SiCNT anode material to some extent and lowered the energy barriers. Graphical abstract (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - June 26, 2017 Category: Chemistry Source Type: research

C4H4 radical cation isomers: Generation, structure, stability, and isomerization reactions
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Kiew Shaphrang Kharnaior, Asit K. Chandra, R.H. Duncan Lyngdoh The B3LYP, M06-2X and MP2 methods are used to study the generation, relative stability, structure, charge and spin distributions, along with isomerization reactions, of C 4 H 4 + radical cations in gas phase. The highly endothermic generation of C 4 H 4 + species by ionization of neutral C4H4 precursors is for 7 cases. Stability orders for 10 C 4 H 4 + isomers as derived from the three methods correlate well with one another, where methylenecyc...
Source: Computational and Theoretical Chemistry - June 26, 2017 Category: Chemistry Source Type: research

Influences of metal (Cu, Ag, Au) doping on (AlO)2/(AlO)2 − square-planar units
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Xiaowei Han, Mei Qin, Xueying Zhang, Zheng Sun, Xiaoyan Li Due to their unique chemical reactivity, transition-metal-doped aluminum oxides have received increased attention. In this work, the influences of metal (Cu, Ag, Au) doping on small (AlO)2 and (AlO)2 − rings have been investigated using density functional theory (DFT) and topological analysis of the electron density. The calculated results show that the effects of doping Cu and Ag are similar to those of Au. Thus, Cu and Ag can be used as the substitutio...
Source: Computational and Theoretical Chemistry - June 24, 2017 Category: Chemistry Source Type: research

OH-initiated atmospheric oxidation mechanism of 1-chloropyrene: A theoretical study
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Yan Wang, Xiaolan Zeng The atmospheric oxidation mechanism of 1-chloropyrene (1-ClPy) initiated by OH radical was studied using density functional theory calculations. The molecular structures of all stationary points included in the studied reactions were optimized at the MPWB1K/6-311+G(3df,2p) level. By considering the Wigner tunneling correction, traditional transition state theory was employed to estimate the rate constants for key elementary reaction steps. The computed results show that the addition reactions be...
Source: Computational and Theoretical Chemistry - June 24, 2017 Category: Chemistry Source Type: research

Influence of different micro-vibrational behavior on the thermodynamic properties of SO gas
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Jia Fu, Qunchao Fan, Guoyue Liu, Huidong Li, Yonggen Xu, Zhixiang Fan, Yi Zhang The effects of different micro-vibrational motions of sulfur oxide on its thermodynamic properties have been carried out. The theoretical full set of vibrational levels {Eυ } and the maximum vibrational quantum number υ max of the ground electronic state X3Σ− of SO molecule are obtained using the variational algebraic method (VAM) for vibrational motions. In the temperature range of 300–4000K, the molar in...
Source: Computational and Theoretical Chemistry - June 24, 2017 Category: Chemistry Source Type: research

Microsolvation of lithium iodide dimer studied by ab initio calculations
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Ren-Zhong Li, Yang-Yang Liu, Man Yang The structures of microsolvated (LiI)2 −(H2O)n (n=0–6) clusters and their corresponding neutrals were determined using ab initio calculations. One Li-I distance in (LiI)2 −(H2O)n abruptly increases at n=5, thus a I atom is firstly seperated out from the (LiI)2 − unit. For the neutrals, the notable elongation of Li-I distances occurs at n=4, and a I atom prefer to leave the (LiI)2 unit. The charge analyses show that the excess electrons mainly localizes on t...
Source: Computational and Theoretical Chemistry - June 23, 2017 Category: Chemistry Source Type: research

A theoretical study on the C30X15Y15 (X=B, and Al; Y=N, and P) heterofullerenes
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): A. Hosseinian, A. Bekhradnia, E. Vessally, L. Edjlali, M.D. Esrafili Using density functional theory calculations, we investigated the stability, solubility, structural, electronic, and optical properties of C30X15Y15 (X=B, and Al; Y=N, and P) heterofullerenes. The C30B15N15 is found to be the most stable heterofullerene with standard formation enthalpy (ΔH°f) of 222.2kcal/mol, followed by C30Al15N15 (ΔH°f =891.6kcal/mol). The relative stability of fullerenes are as follows: BN>C60 >A...
Source: Computational and Theoretical Chemistry - June 20, 2017 Category: Chemistry Source Type: research

Changing pictures of molecular faces and depths of potential acting on an electron in molecule for intramolecular proton transfer reactions of formic acid and malonaldehyde
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Dong-Xia Zhao, Jian Zhao, Miao Song, Zun-Wei Zhu, Cheng-Cheng Chen, Yu-Jing Song Proton transfer plays a critical role in many chemical and biological processes. MF theory is used to investigate intramolecular proton transfer reactions of formic acid and malonaldehyde. A MELD package with our in-house program is employed to calculate potential acting on an electron within a molecule (PAEM), molecular face (MF), molecular intrinsic characteristic contour (MICC) parameters, molecular face surface area (MFSA), as well as...
Source: Computational and Theoretical Chemistry - June 19, 2017 Category: Chemistry Source Type: research

From quantum superposition to orbital communication
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Dariusz W. Szczepanik, Emil Zak, Janusz Mrozek The orbital communication theory (OCT) by Nalewajski is derived step by step from first principles of quantum mechanics. It is shown that the entropy representation within the molecular orbital theory arises as a natural consequence of the probabilistic interpretation of quantum superposition. The algebra of selected types of molecular information channels is reinvestigated within the framework of the theory of Markov chains and several representative models of molecular ...
Source: Computational and Theoretical Chemistry - June 17, 2017 Category: Chemistry Source Type: research

Theoretical study of the structure and spectra for the γ and β systems of NO
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Junxia Cheng, Hong Zhang, Xinlu Cheng Highly correlated ab initio calculations were performed in order to obtain an accurate determination of the γ(A2Σ+-X2П) system and β(B2П-X2П) system of the NO molecule. The multi-reference configuration interaction (MRCI) approach was used to investigate the potential energy curves and transition dipole moment curves of the γ and β systems. The potential energy curves of the three states agreed well with Rydberg-Klein-Rees (RKR) potential using aug-cc-...
Source: Computational and Theoretical Chemistry - June 15, 2017 Category: Chemistry Source Type: research

Density functional theory studies of the uncatalysed gas-phase oxidative dehydrogenation conversion of n-hexane to hexenes
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): N.E. Damoyi, H.B. Friedrich, H.G. Kruger, D. Willock Density Functional Theory (DFT) modelling studies were conducted for the activation of n-hexane in the gas-phase under experimental conditions of 573, 673 and 773K. The aim of the study was to establish the most favourable radical mechanism for the oxidative dehydrogenation (ODH) of n-hexane to 1- and 2-hexene. Modelling of the 3-hexene pathway was omitted due to absence of this product in laboratory experiments. Computations were performed using GAUSSIAN 09W and mole...
Source: Computational and Theoretical Chemistry - June 15, 2017 Category: Chemistry Source Type: research

The crucial role of water clusters (H2O)n (n=0 –5) on the catalytic oxidation of AsH3: An accurate theoretical investigation
In this study, the role of explicit water molecules on the AsH3 catalytic oxidation AsH3 +O2 +nH2O (n=0–5) was investigated using Density Functional Theory (DFT) method at B3LYP/6-311+G (d,p) level. The addition of (H2O)n (n=1–5) shows promoting catalytic effect on the oxidation process by reducing the reaction barrier energy of 3.27–10.70kcal/mol compared to the reaction without water molecule (16.44kcal/mol). One explicit H2O addition shows best catalytic effect on the oxidation process. The decreasing order of reaction energy barrier is 0H2O>(H2O)5 >(H2O)4 >(H2O)2 >(H2O)3 &a...
Source: Computational and Theoretical Chemistry - June 15, 2017 Category: Chemistry Source Type: research

Propane CH activation by palladium complexes bearing ligands with Charge-shift bonding characteristics: A DFT study
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Dongxia Ma, Congjie Zhang Using density functional theory (DFT), we have investigated the conversion of propane to propyl trifluoroacetate catalyzed by five kinds of (bis-2BB)PdBr2 complexes (bis-2BB is the derivatives of bis-2-borabicyclo[1.1.0]but-1(3)-ene). Calculated results indicate that the (bis-2BB)PdBr2 catalysts are superior to the popular (bis-NHC)PdBr2 complex in the desired catalytic process, consistent with the previous results of the conversion of methane to methyl trifluoroacetate catalyzed by (bis-2BB)...
Source: Computational and Theoretical Chemistry - June 12, 2017 Category: Chemistry Source Type: research

Conversion of toluene into benzyl radical on anatase TiO2 (001) surface
In this study, the initial step of toluene dissociation, that is, the formation of benzyl radical through the reaction with hydroxyl group on anatase (001) surface is investigated using density functional theory calculations. The calculated results show that the toluene is physisorbed on the pristine TiO2 surface, and it is converted into benzyl radical when it interacting with surface hydroxyl groups through methyl group of toluene. It has been found that the interaction between toluene and TiO2 surface through OH group is enhanced by the presence of Ag tetramer. The calculated reaction energy profile shows that the react...
Source: Computational and Theoretical Chemistry - June 12, 2017 Category: Chemistry Source Type: research

A theoretical study on the isomers of the B5TB heteroacene for improved semiconductor properties in organic electronics
In this study, we re-worked the structure of B5TB through isomerisation of the terminal benzothiophene rings, which gave a small pool of six isomers. These were theoretically screened to (1) probe their fundamental electronic and optical properties of these new structures, and (2) determine if an isomer of the same chemical formula could impart improved properties over the parent B5TB. In the present study, Density Functional Theory (DFT), Koopmans’ Theorem and two electron propagator theories (EPTs) such as the Outer Valence Green’s Function (OVGF) and the third-order pole (P3) were applied to calculate proper...
Source: Computational and Theoretical Chemistry - June 10, 2017 Category: Chemistry Source Type: research

Theoretical study on anomalous kinetic isotope effects in H/Mu addition to pyrazine: Effects of water microsolvation in solution kinetics
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Toshiyuki Takayanagi, Shoichi Koido Previous experimental studies have shown that addition of H and Mu atoms to pyrazine in aqueous solution leads to different reaction products. H adds to the N atom of the pyrazine ring, whereas Mu adds preferentially to the C atom. In this work, to explain this anomalous isotope effect, we performed reaction path analyses for the H/Mu+pyrazine·(H2O) n (n =0–2) reactions at the density functional theory level by considering microsolvation effects. Without water microsolv...
Source: Computational and Theoretical Chemistry - June 10, 2017 Category: Chemistry Source Type: research

Online complete basis set limit extrapolation calculator
Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Vladislav Vasilyev Calculation of the asymptotic convergence of energies and other properties to their complete basis set (CBS) limit in Quantum Chemistry may be tedious, so a CBS Limit Extrapolation Calculator was developed to perform this task. Currently it implements 9 different extrapolation expressions and it was written in a JavaScript programming language. Calculator is implemented as a Dynamic HTML (DHTML) page, with the JavaScript handling input, its validation, numerical calculations as well as plotting usin...
Source: Computational and Theoretical Chemistry - June 10, 2017 Category: Chemistry Source Type: research

Revisited the mechanism of the transition metal catalyzed cycloetherification of ω-hydroxy propargylic ester: A DFT study
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Arpita Chatterjee, Rohini Saha, Dibyajyoti Panja, Sujit Ghosh, Sonjoy Mondal, Animesh Ghosh, Gourab Kanti Das DFT calculations on a reported mechanistic pathway of a platinum catalyzed cycloetherification process reveal the requirement of high activation free energy for the progress of the reaction. Parallel calculations on some alternative pathways suggest that a solvent assisted proton transferring mechanism is much more likely to be relevant to explain the formation of the product. Our calculation also supports the e...
Source: Computational and Theoretical Chemistry - June 8, 2017 Category: Chemistry Source Type: research

Theoretical study of Ni+ assisted CC and CH bond activations of propionaldehyde in the gas phase
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Pei-Pei Zhao, Yong-Cheng Wang, Yang Sheng, Yi-Ming Jia The reactions of Ni+ with propionaldehyde in the gas phase have been systematically investigated using density functional theory at the B3LYP/def2-TZVP level. The decomposition reaction mechanism has been identified. Our calculations indicated that Ni+ can assist decomposition of propionaldehyde to form Ni+CO and C2H6 through two types of reaction channel: CC bond activation and CH bond activation. In addition, charge decomposition analysis (CDA) was carried out to ...
Source: Computational and Theoretical Chemistry - June 7, 2017 Category: Chemistry Source Type: research

Electronic structure, stability, and aromaticity of H2B2XH (X=N, P) molecules: A theoretical study
Publication date: 1 August 2017 Source:Computational and Theoretical Chemistry, Volume 1113 Author(s): Sabnam S. Ullah, Lakhya Jyoti Mazumder, Samhita Kaushik, Navanita Das, Mainao Sona Brahma, Pankaz K. Sharma, Ankur Kanti Guha Ab initio calculations at the CCSD(T) level of theory predict that substitution of a ring member in B3H3 2− by a group 15 element (N or P) may result in a stable, neutral three-membered aromatic ring. Mechanistic study reveals a plausible synthetic pathway – a click reaction between B2H2 and XH (X=N and P). Various NICS based calculations as well as topological analyses of electron den...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Electron correlations in an excited state of a quantum dot in a uniform magnetic field
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Marlina Slamet, Viraht Sahni Electron correlations in a two-electron two-dimensional ‘artificial atom’ or quantum dot (with harmonic confining potential) in the presence of a uniform magnetic field in an excited singlet state are studied via quantal density functional theory (QDFT). QDFT allows for the separation of the electron correlations due to the Pauli exclusion principle and Coulomb repulsion, as well as the determination of the contribution of these correlations to the kinetic energy. The QDFT mappin...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

On bonding in bis(dimethylglyoximato)nickel(II)
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Shanti G. Patra, Nilangshu Mandal, Ayan Datta, Dipankar Datta The Ni(II) complex of dimethylglyoxime (dmgH where H is dissociable oxime proton) occurs as an infinite chain of the discrete molecule Ni(dmgH)2 with a NiNi distance of 3.24Å. Density Functional Theoretical calculations, using LanL2DZ and 6-31+G(2d,p) as two sets of basis functions and M06-2X as the functional, show that the dimeric unit [Ni(dmgH)2]2 has a cohesive energy more than 20kcalmol−1. This energy is almost same in the corresponding hypot...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

A benchmark study of Li2+, Li2 −, LiH+ and LiH−: Quantum Monte-Carlo and coupled-cluster computations
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Saeed Nasiri, Mansour Zahedi For the first time, very accurate potential energy curves (PEC) have been computed by the all electron Diffusion Quantum Monte-Carlo (DMC) and CCSD(T) methods for the ground-state of the Li2 +, Li2 −, LiH+ and LiH− ions. In addition to the molecular moieties, Li+, Li−, H− ions have also been studied by the aforementioned methods. The employed trial wave functions for the DMC calculations are a multiplication of multi-configuration expansions which are prepared by the ...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

The CO2-O2 van der Waals complex
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Friedrich Grein Using the explicitly correlated CCSD(T)-F12 method with cc-pVXZ-F12 (VXZ-F12) and aug-cc-pVXZ (AVXZ) (up to X=Q) basis sets, various structures of the triplet CO2-O2 complex were investigated. Accordingly, the planar slipped-tilted isomer is most stable, with a binding energy (ΔE) of 230cm−1, followed by the cross-shaped C2v-X isomer, having ΔE=202cm−1 and by the in-plane T-shaped C2v-Ta isomer with ΔE=181cm−1 (energies obtained from counterpoise corrected optimization...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

A DFT computational study on the molecular mechanism of reaction between pyridinium salts and π-deficient ethylenes: Why furan derivatives are formed instead of feasible cyclopropane derivatives and [3+2] cycloadducts?
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Saeedreza Emamian, Radomir Jasiński The reaction between 1-(2-amino-2-oxoethyl)pyridinium ylide 4 (PY4) and 1-methylene-3,4-dihydronaphthalen-2(1H)-one 5 (MDN5) in the presence of acetonitrile (CH3CN) was theoretically studied at the M06-2X/6-31G(d,p) computational level. Calculated relative Gibbs free energies indicate that encounters between PY4 and MDN5 in the reaction mixture result in the formation of the highly zwitterionic betaine-like intermediate IM1ca in an entirely C1C5 regio- and a cisoid-anti stereoselecti...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Theoretical studies of a series of azaoxaisowurtzitane cage compounds with high explosive performance and low sensitivity
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Yong Pan, Weihua Zhu, Heming Xiao Ten novel azaoxaisowurtzitane cage compounds were designed by introducing the oxygen atoms into the azaisowurtzitane cage to replace the N-NO2 groups. Then, their heats of formation (HOFs), energetic properties, strain energies, thermal stability, and impact sensitivity were studied by using density functional theory. The introduction of the oxygen atom in the cage is not helpful for increasing the HOFs, densities, and energetic properties of parent compound CL-20. But all the title com...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

A comprehensive density functional theory study on molecular structures of (5, 5) carbon nanotube doped with B, N, Al, Si, P, Co, and Ni
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Fahimeh Shojaie Armchair single-walled carbon nanotubes (SWNTs), which were doped with B, N, Al, Si, P, Co, and Ni, have been studied using computational simulations based on density functional theory (DFT). The topological analysis and the electron localization function show that the nature of the interaction between carbon atoms and the dopant X atoms is not purely covalent or an ionic. In order to gain a deeper understanding of the interaction between X atoms and C atoms, calculations of natural bond orbital (NBO) an...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Quantum chemical study on phenethylamines reveals new cation structures
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Miroslav M. Ristić, Milena Petković, Mihajlo Etinski Phenethylamines are compounds known by their psychoactive and stimulant effects. Their physiological activity is strongly conformer dependent. In this work, the quantum chemical investigation of neutral and cationic phenylethylamine, amphetamine and methamphetamine was performed in order to determine the most stable physiologically relevant conformers. Calculations were performed employing density functional theory and ωB97XD functional. A previously unknown d...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Theoretical investigation of the diatomic Van der Waals systems Ca+He and CaHe
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Safa Mtiri, Leila Mejrissi, Héla Habli, Attieh A. Al-Ghamdi, Brahim Oujia, Florent Xavier Gadéa An ab initio investigation has been performed for the ground and several excited states of Ca+He and CaHe systems. The potential energy curves, spectroscopic constants, vibrational levels energies and electric dipole moments have been calculated and analyzed. The ab initio method uses the pseudo-potentials technique, Core Polarization Potentials (CPP) and Full Configuration Interaction (FCI). The number of activ...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Exploring electronic and optical properties of CH3NH3GeI3 perovskite: Insights from the first principles
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Yuqiu Jiao, Yuanyuan Lv, Jia Li, Mang Niu, Zhenqing Yang The three phases for MAGeI3 in different temperatures play an important role in hybrid organic-inorganic perovskites solar cells. Up to now, their intrinsic nature still lacks systematic study. In this work, we established the crystal structures of MAGeI3 (MA+ =CH3NH3 +) with orthorhombic, tetragonal and cubic phases. The electronic and optical properties of MAGeI3 with three crystal structures including band gaps, density of states (DOS), absorption spectrum and ...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

A comparison of pseudospectral methods for the solution of the Schr ödinger equation; the Lennard-Jones (n,6) potential
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Bernie D. Shizgal The eigenvalues of the Schrödinger equation for the Lennard-Jones (n,6) potential with n =8, 10 and 12, have been determined by numerous workers with different numerical methods. In this paper, we consider a pseudospectral method based on a grid defined by the quadrature points associated with nonclassical polynomials. The polynomials are orthogonal with respect to the weight function defined by the ground state wave function for a Morse potential that approximates the Lennard-Jones potential. The...
Source: Computational and Theoretical Chemistry - May 27, 2017 Category: Chemistry Source Type: research

Carbon nanotubes functionalized with titanium complexes for hexavalent chromium adsorption: An ab initio approach
Publication date: 1 August 2017 Source:Computational and Theoretical Chemistry, Volume 1113 Author(s): Ana Paula Schwarz, Carlos Pérez Bergmann, Solange Binotto Fagan This work presents an original study of the structural and electronic properties of doped single-walled carbon nanotubes (SWCNT) through titanium complexes and the possibility of adsorption and reduction of hexavalent chromium Cr(VI) using density functional theory. Cr(VI) is one of the major environment pollutants, its removal presents several difficulties, and it results in industrial pollution, causing health problems. The adsorption of Cr(VI) was ...
Source: Computational and Theoretical Chemistry - May 26, 2017 Category: Chemistry Source Type: research

Theoretical study of the Wittig, aza-Wittig and arsa-Wittig reactions of Me3P=XH ylide (X=CH, N and As) with cyclic ketones in the gas phase and solution phase
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Nisha Jarwal, Pompozhi Protasis Thankachan A computational study of the comparative reactivity of the Wittig, aza-Wittig and arsa-Wittig reactions of cyclopentanone and cyclobutanone with Me3P=XH ylide (X=CH, N and As) in the gas phase has been performed at B3LYP/6-31G∗∗ level of theory. Calculations have also been performed using integral equation formalism polarizable continuum model (IEFPCM), with THF solvent at B3LYP/6-31G∗∗ level of theory. In the gas phase as well as in solvent, these r...
Source: Computational and Theoretical Chemistry - May 26, 2017 Category: Chemistry Source Type: research

A novel strategy for SOx removal by N-doped TiO2/WSe2 nanocomposite as a highly efficient molecule sensor investigated by van der Waals corrected DFT
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Amirali Abbasi, Jaber Jahanbin Sardroodi On the basis of density functional theory (DFT) calculations, we demonstrate the potential applicability of TiO2/WSe2 nanocomposite as a highly sensitive molecule sensor for SO2 and SO3 molecules. SOx molecules chemically adsorb on TiO2/WSe2 nanocomposite via strong chemical bonds. With vdW interactions included, the adsorption energies were corrected for long range dispersion energy, indicating adsorption energetic and possible configurations of SOx molecules towards TiO2/WSe2 n...
Source: Computational and Theoretical Chemistry - May 26, 2017 Category: Chemistry Source Type: research

Cyclization mechanisms of the cyclic dimer of aziridine aldehyde with vinyl aldehyde
Publication date: 1 August 2017 Source:Computational and Theoretical Chemistry, Volume 1113 Author(s): Xueli Cheng Aziridine aldehydes are the notable representative of a limited number of reported amphoteric molecules containing aziridine and aldehyde groups, which can react both as an acid and as a base. In the present work, the intriguing dimerization mechanism of aziridine aldehyde free from any substituents and solvents, as well as the addition and cyclization mechanisms of its dimer with vinyl aldehyde in acetonitrile were investigated systematically. The N H bond of aziridine aldehyde couples with the C O bond in...
Source: Computational and Theoretical Chemistry - May 24, 2017 Category: Chemistry Source Type: research

DFT insight on oxygen adsorbed platinum trimer cluster (Pt3) for CO oxidation
Publication date: 15 August 2017 Source:Computational and Theoretical Chemistry, Volume 1114 Author(s): Satyajit Dey Baruah, Nand K. Gour, Plaban J. Sarma, Ramesh C. Deka Oxidation of CO has been performed systematically over oxygen adsorbed platinum trimer cluster (Pt3) using hybrid density functional theory (DFT) method. Terminal, end on and bridging site of oxygen adsorbed Pt3 have been employed for the oxidation reaction. We have characterized all the stationary points on the potential energy surface along with transition states for prediction of most suitable CO oxidation pathway. The binding energies are determined ...
Source: Computational and Theoretical Chemistry - May 24, 2017 Category: Chemistry Source Type: research