A molecular electron density theory study of the asymmetric hetero-Diels-Alder cycloaddition reaction between ferrocenyl-substituted thiabutadiene and methyl propiolate
Publication date: Available online 9 August 2018Source: Computational and Theoretical ChemistryAuthor(s): Tooba Afshari, Mohsen MohsenniaAbstractThe present work includes a molecular electron density theory (MEDT) study on the regioselectivity and molecular mechanism of 6-ferrocenyl-substituted 4H-thiopyran (cycloadduct 6) synthesis over the course of an asymmetric hetero-Diels-Alder (HDA) cycloaddition reaction between ferrocenyl-substituted thiabutadiene (FTBD 4) and methyl propiolate (MP 5) at 298 K in the presence of chloroform. In agreement with the experimental findings, the obtained results obviously indicate that t...
Source: Computational and Theoretical Chemistry - August 10, 2018 Category: Chemistry Source Type: research

Theoretical Study on Electronic Properties of Curved Graphene Quantum Dots
Publication date: Available online 4 August 2018Source: Computational and Theoretical ChemistryAuthor(s): Naruwan Pattarapongdilok, Vudhichai ParasukAbstractElectronic properties of curved graphene quantum dots (CGQDs) were studied using Density Functional Theory (DFT) method. Two shapes of the zigzag-edged CGQDs, i.e., rhomboidal (RGQDs) and hexagonal (HGQDs) graphene quantum dots, and each with five sizes were studied. For each GQD, its structure was curved along symmetry-unique folding axes at 20, 40, 60, 80, 100, 120, 140, and 160. There are four unique folding axes (FA1, FA2, FA3, and FA4) for RGQDS and only two axes ...
Source: Computational and Theoretical Chemistry - August 5, 2018 Category: Chemistry Source Type: research

Theoretical calculations of photoelectron spectrum of (Au–CO2)− anion
Publication date: 15 September 2018Source: Computational and Theoretical Chemistry, Volume 1140Author(s): Yuya Watabe, Takaaki Miyazaki, Eiki Ozama, Toshiyuki Takayanagi, Yoshi-ichi SuzukiAbstractPhotoelectron spectra of the (Au–CO2)− anion complex have been calculated using both quantum path-integral and classical molecular dynamics methods to interpret the experimentally measured spectrum, showing a double-peak feature corresponding to two different anion configurations of Au·CO2− and Au−·CO2. The anionic potential energy surfaces have been developed on the basis of density-functiona...
Source: Computational and Theoretical Chemistry - August 4, 2018 Category: Chemistry Source Type: research

DFT study of single-walled carbon hollows as media for hydrogen storage
Publication date: Available online 3 August 2018Source: Computational and Theoretical ChemistryAuthor(s): Igor K. Petrushenko, Konstantin B. PetrushenkoAbstractUnderstanding the interaction of hydrogen molecules with hollow materials is crucial in the fields of hydrogen storage, sensors, catalysis, and fuel cells. In this paper, we studied hydrogen adsorption on single-walled carbon hollows by means of DFT-D3 calculations. These structures adsorb H2 molecules significantly stronger (adsorption energy, Ea, of -12.55 to -20.56 kJ/mol) than coronene (-4.15 kJ/mol), the representative of graphene, and corannulene (-7.83 kJ/mol...
Source: Computational and Theoretical Chemistry - August 3, 2018 Category: Chemistry Source Type: research

Basicity of Amines and Some Related Compounds From Energy Decomposition Analysis
Publication date: Available online 2 August 2018Source: Computational and Theoretical ChemistryAuthor(s): Rodrigo M. PontesAbstractAcidities and basicities are normally rationalized with the help of concepts like inductive and delocalization effects. There are, however, difficulties in estimating these quantities for most of systems. In this work, energy decomposition analysis has been used to interpret the basicity of a series of nitrogen compounds. With the help of CMOEDA (LMOEDA) partitioning scheme, the increase of basicities with the increasing alkyl chain length of amines was attributed mainly to polarization (orbita...
Source: Computational and Theoretical Chemistry - August 2, 2018 Category: Chemistry Source Type: research

Exohedral complexation of B39- with ECp∗+ half-sandwich complexes (ESi, Ge, Sn, Pb): A DFT study
Publication date: 15 September 2018Source: Computational and Theoretical Chemistry, Volume 1140Author(s): Ayan Majumder, Manas Ghara, Pratim K. ChattarajAbstractThe hexagonal and heptagonal holes of B39- allow its complexation with a half sandwich complex ECp∗+ (ESi, Ge, Sn, Pb). Structure and the nature of bonding of (η6/7-B39)E(η5-Cp∗) are explored through the density functional theory based computation. (η6-B39)E(η5-Cp∗) isomers are more stable than (η7-B39)E(η5-Cp∗) and the energy difference between these two isomers decreases down the group from Si to Pb. The dissoci...
Source: Computational and Theoretical Chemistry - August 2, 2018 Category: Chemistry Source Type: research

Preferred conformational structures of disaccharides with β-1,4-linked N-acetylglucosamine and D-mannose in the gas phase: A tree-step computational approach study
Publication date: 15 September 2018Source: Computational and Theoretical Chemistry, Volume 1140Author(s): Jianming Gao, Dong Chen, Ran Song, Huanlu Xue, Tianxiang Wang, Bo LiuAbstractN-glycans are highly crucial to the potential application prospect of glycoprotein. However, its structural diversity and instability severely limit its further research. Here we apply the tree-step computational approach to investigate preferred structures of disaccharides with β-1,4-linked N-acetylglucosamine and D-mannose of core pentasaccharide in N-glycans. Due to the structural character of disaccharides, hydrogen bonds (H-bonds) ar...
Source: Computational and Theoretical Chemistry - August 1, 2018 Category: Chemistry Source Type: research

Thermal decomposition of oxetan-2-one molecule in the light of DFT and CASPT2 modelling
Publication date: Available online 30 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Katarzyna Pustuła, Anna Płonka, Marcin MakowskiAbstractOnly one path of oxetan-2-one pyrolysis, which results in carbon dioxide and ethene, was observed experimentally. Two other paths resulting in ketene and formaldehyde or acetyl aldehyde and carbon monoxide, respectively, were only hypothesized. In this research we use multi-reference quantum chemistry approach to study the possible decomposition pathways. Using a multi-step procedure involving low-cost genetic algorithm based pre-search and subsequent DFT and CASP...
Source: Computational and Theoretical Chemistry - July 31, 2018 Category: Chemistry Source Type: research

Theoretical calculations of photoelectron spectrum of (Au−CO2)− anion
Publication date: Available online 30 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Yuya Watabe, Takaaki Miyazaki, Eiki Ozama, Toshiyuki Takayanagi, Yoshi-ichi SuzukiAbstractPhotoelectron spectra of the (Au−CO2)− anion complex have been calculated using both quantum path-integral and classical molecular dynamics methods to interpret the experimentally measured spectrum, showing a double-peak feature corresponding to two different anion configurations of Au·CO2− and Au−·CO2. The anionic potential energy surfaces have been developed on the basis of density-functional...
Source: Computational and Theoretical Chemistry - July 31, 2018 Category: Chemistry Source Type: research

Quantum-chemical and kinetic study of the reactions of the ClSO2 radical with H, O, Cl, S, SCl and ClSO2 in the atmosphere of Venus
Publication date: 15 September 2018Source: Computational and Theoretical Chemistry, Volume 1140Author(s): Adela E. Croce, Carlos J. CobosAbstractRate constants for the reactions between the ClSO2 radical and H, O, Cl, S, SCl and ClSO2 were studied over the 150–700 K temperature range employing the statistical adiabatic channel model/classical trajectory approach and the canonical transition state theory on potential energy surfaces based on G4//B3LYP/6-311++G(3df,3pd) calculations. For these processes the following rate constants (in cm3 molecule−1 s−1) are predicted: 2.71 x 10- 11(T/250)0.47 (ClSO2 +...
Source: Computational and Theoretical Chemistry - July 31, 2018 Category: Chemistry Source Type: research

Computational search for metastable high-spin C5Hn (n = 4, 5, 6) species
Publication date: 15 September 2018Source: Computational and Theoretical Chemistry, Volume 1140Author(s): Maria G. Moreno-Armenta, Harrison Rojak Pearce, Pierre Winter, Andrew L. CooksyAbstractA search for small hydrocarbon radicals with two electronic spin states of comparable stability has identified 9 candidates among singlet and triplet states of various isomers of cyclic C5H4, cyclic C5H6, and acyclic C5H6. No quartet states of C5H5 were found to be comparable in energy to the doublet state of the same structural isomer. Equilibrium geometries, term energies, and vertical excitation energies have been predicted by CCS...
Source: Computational and Theoretical Chemistry - July 29, 2018 Category: Chemistry Source Type: research

The energetics and kinetics of the CH3CHO + (CH3)2NH/CH3NH2 reactions catalyzed by a single water molecule in the atmosphere
We report that a single water molecule plays a catalytic role in the reaction of dimethylamine with acetaldehyde. (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - July 29, 2018 Category: Chemistry Source Type: research

Exohedral Complexation of B39- with ECp∗+ Half-sandwich Complexes (E= Si, Ge, Sn, Pb): A DFT Study
Publication date: Available online 27 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Ayan Majumder, Manas Ghara, Pratim K. ChattarajAbstractThe hexagonal and heptagonal holes of B39- allow its complexation with a half sandwich complex ECp∗+ (E= Si, Ge, Sn, Pb). Structure and the nature of bonding of (η6/7-B39)E(η5-Cp∗) are explored through the density functional theory based computation. (η6-B39)E(η5-Cp∗) isomers are more stable than (η7-B39)E(η5-Cp∗) and the energy difference between these two isomers decreases down the group from Si to Pb. The dissoc...
Source: Computational and Theoretical Chemistry - July 28, 2018 Category: Chemistry Source Type: research

Molecular Structure and Absorption Spectral Properties of Corrole Isomers: DFT and TDDFT-IEFPCM investigations
Publication date: Available online 27 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Wen-Qiong Zhang, Xiao-Jun Jin, Hong-Yu Cao, Qian Tang, Ai-Ling Wang, Xue-Fang ZhengAbstractCorrole has become one of the most important branches of porphyrin chemistry for the better optical properties than traditional porphyrin. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been utilized to simulate the molecular structures and electron absorption spectra of corrole and isomers. The molecular structure and charge distribution results revealed that the inner hydrogen atoms of...
Source: Computational and Theoretical Chemistry - July 27, 2018 Category: Chemistry Source Type: research

Chiral Recognition of Propranolol Enantiomers by Chiral Ionic Liquid: a Quantum Chemical Calculation Analysis
Publication date: Available online 27 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Tahereh Sedghamiz, Farhad Ghalami, Elaheh Sedghamiz, Maryam BahramiAbstractElectronic structure and noncovalent interactions of the complexes of 1-butyl-3-methylimidazolium (T-4)-bis[(αS)-α-(hydroxy-O)benzeneacetato-κO] borate ionic liquid (IL) with propranolol hydrochloride enantiomers are analyzed using hybrid M06-2X density functional theory. Based on the binding energies, the S-Propranolol/IL (S-Pr/IL) complex is more stable than the R-Propranolol/IL (R-Pr/IL), which is in accordance with the exper...
Source: Computational and Theoretical Chemistry - July 27, 2018 Category: Chemistry Source Type: research

Probing the geometric structures and bonding mechanisms of CuI hybrid clusters: Cu4I4−/0
We present a theoretical investigation on the geometric structures and bonding mechanisms in Cu4I4−/0 clusters using density functional theory calculations. Different density functional methods (B3LYP, PBE, and BPW91) assign the relative energies to these isomers. The results showed that Cu4I4− anion has a C2h symmetric planar structure with the four I atoms surrounding the Cu4 rhombic framework, whereas Cu4I4 neutral adopts D2d symmetric V-shaped structure. Bond length, Wiberg bond order, and molecular orbital analyses suggest that the CuI interactions in Cu4I4−/0 are weak. Interestingly, Cu4I4− an...
Source: Computational and Theoretical Chemistry - July 27, 2018 Category: Chemistry Source Type: research

Editorial Board
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - July 24, 2018 Category: Chemistry Source Type: research

Electronic Structure and Spectral Properties of Indole Based Fluorescent Styryl Dyes: Comprehensive Study on Linear and Non-Linear Optical Properties by DFT/TDDFT method
Publication date: Available online 24 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Dhanraj R. Mohbiya, Nagaiyan SekarAbstractThe photophysics, linear and non-linear optical properties of indole based fluorescent styryl dyes are investigated with density functional theory and time-dependent density functional theory. The performance of seven global hybrid functionals - B3LYP, PBE0, BHHLYP, M06, M06-L, M06-2X, M06-HF and six range separated hybrid functionals - CAM-B3LYP, HISSbPBE, HSEH1PBE, ωB97, ωB97X, ωB97XD with poples [6-311++G(d,p)] and correlation consistence (cc-pVDZ, cc-pVTZ) ...
Source: Computational and Theoretical Chemistry - July 24, 2018 Category: Chemistry Source Type: research

Preferred conformational structures of disaccharides with β-1,4-linked N-acetylglucosamine and D-mannose in the gas phase: a tree-step computational approach study
Publication date: Available online 23 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Jianming Gao, Dong Chen, Ran Song, Huanlu Xue, Tianxiang Wang, Bo LiuAbstractN-glycans are highly crucial to the potential application prospect of glycoprotein. However, its structural diversity and instability severely limit its further research. Here we apply the tree-step computational approach to investigate preferred structures of disaccharides with β-1,4-linked N-acetylglucosamine and D-mannose of core pentasaccharide in N-glycans. Due to the structural character of disaccharides, hydrogen bonds (H-bonds...
Source: Computational and Theoretical Chemistry - July 23, 2018 Category: Chemistry Source Type: research

The energetics and kinetics of the CH3CHO + (CH3)2NH/CH3NH2 reactions catalyzed by a single water molecule in the atmosphere
We report that a single water molecule plays a catalytic role in the reaction of dimethylamine with acetaldehyde. (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - July 23, 2018 Category: Chemistry Source Type: research

Computational Search for Metastable High-Spin C5Hn (n=4,5,6) Species
Publication date: Available online 21 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Maria G. Moreno-Armenta, Harrison Rojak Pearce, Pierre Winter, Andrew L. CooksyAbstractA search for small hydrocarbon radicals with two electronic spin states of comparable stability has identified 9 candidates among singlet and triplet states of various isomers of cyclic C5H4, cyclic C5H6, and acyclic C5H6. No quartet states of C5H5 were found to be comparable in energy to the doublet state of the same structural isomer. Equilibrium geometries, term energies, and vertical excitation energies have been predicted by CCSD...
Source: Computational and Theoretical Chemistry - July 21, 2018 Category: Chemistry Source Type: research

Understanding the structure, reactivity and absorption spectra of borazine doped pillar[5]arene: A DFT study
Publication date: Available online 19 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Himakshi Sharma, Bhabesh Ch. Deka, Bapan Saha, Pradip Kr. BhattacharyyaAbstractPillar[5] arene and its derivatives act as useful complexing agents and find utility in various fields of chemistry. Effects of doping borazine unit in pillar[5] arene with respect to its geometry, reactivity and spectroscopic properties are discussed in the light of density functional theory and density functional reactivity theory. Reactivity parameters namely energy of the HOMO, global hardness and chemical potential are used to explain th...
Source: Computational and Theoretical Chemistry - July 20, 2018 Category: Chemistry Source Type: research

Probing the geometric structures and bonding mechanisms of Cu−I hybrid clusters: Cu4I4−/0
We present a theoretical investigation on the geometric structures and bonding mechanisms in Cu4I4−/0 clusters using density functional theory calculations. Different density functional methods (B3LYP, PBE, and BPW91) assign the relative energies to these isomers. The results showed that Cu4I4− anion has a C2h symmetric planar structure with the four I atoms surrounding the Cu4 rhombic framework, whereas Cu4I4 neutral adopts D2d symmetric V-shaped structure. Bond length, Wiberg bond order, and molecular orbital analyses suggest that the Cu−I interactions in Cu4I4−/0 are weak. Interestingly, Cu4I4&mi...
Source: Computational and Theoretical Chemistry - July 20, 2018 Category: Chemistry Source Type: research

Study on the reaction of trimethylaluminum dimer and ammonia based on density functional theory
This study investigated the stable configurations of trimethylaluminum, and provided their primary bond lengths and bond angles. The reaction between the most stable configuration of dimer TMA(C2v) and NH3, was investigated, with the detailed reaction process provided. Further, a complex TMA:NH3 and a monomer m-TMA were produced. The electronic structure and some optical properties of TMA:NH3, such as the density of states, Mulliken charge, bond population, band gap, absorption and reflectivity spectra, were further investigated. The results offer theoretical data for the application of the material TMA:NH3.Graphical abstr...
Source: Computational and Theoretical Chemistry - July 19, 2018 Category: Chemistry Source Type: research

Conformational analysis of a TADDOL-based phosphoramidite P,N ligand in a palladium(II) η3-π-allyl complex
Publication date: Available online 18 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Tülay A. Ateşin, Abdurrahman C. Atesin, Oscar Rodriguez, Diego Rivera, Lohany Y. GarciaAbstractThe most stable conformations of a TADDOL-based phosphoramidite P,N ligand coordinated to a palladium(II) η3-π-allyl fragment have been investigated using molecular mechanical and quantum mechanical calculations. The conformational analysis initially generated 53 unique structures within 5 kcal/mol and subsequent geometry optimization narrowed the number of low-energy conformers down to 13. The two lowest energy c...
Source: Computational and Theoretical Chemistry - July 19, 2018 Category: Chemistry Source Type: research

iQuantum-chemical and kinetic study of the reactions of the ClSO2 radical with H, O, Cl, S, SCl and ClSO2 in the atmosphere of Venus
Publication date: Available online 17 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Adela E. Croce, Carlos J. CobosAbstractRate constants for the reactions between the ClSO2 radical and H, O, Cl, S , SCl and ClSO2 were studied over the 150-700 K temperature range employing the statistical adiabatic channel model/classical trajectory approach and the canonical transition state theory on potential energy surfaces based on G4//B3LYP/6-311++G(3df,3pd) calculations. For these processes the following rate constants (in cm3 molecule-1 s-1) are predicted: 2.71 x 10- 11(T/250)0.47(ClSO2 + H → HCl + SO2); 7...
Source: Computational and Theoretical Chemistry - July 18, 2018 Category: Chemistry Source Type: research

Theoretical estimation of the dissociation energy of CT states at the acenes/C60 interfaces using fragmental-based ALMO method
Publication date: Available online 17 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Xinbo Yang, Wenliang Wang, Shiwei YinAbstractThe dissociated energy (ECTdiss) of charge-transfer state at the DA interaction is a crucial parameter to determine the efficiency of organic solar cells. The ΔSCF-liked absolutely-localized molecular method (ALMO) combining with DFT is applied to investigate ECTdissof the lowest CT with prototype oligoacenes/C60 models. The lowest CT energies obtained from ALMO coupled with various exchange-correlation (XC) functionals behave a correct 1/d asymptotic feature. Although ...
Source: Computational and Theoretical Chemistry - July 18, 2018 Category: Chemistry Source Type: research

Mechanistic insights into the chemoselectivity of PtCln (n = 2, 4)-catalyzed OH insertion and cyclopropanation compared to Rh- and Cu-catalyzed reactions
This study is expected to improve the understanding of platinum-catalyzed reactions for the CX bond construction and provide guidance for the future design of new catalysts and new reactions.Graphical abstract (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - July 14, 2018 Category: Chemistry Source Type: research

Computational design of high energy density materials with zero oxygen balance: a combination of furazan and piperazine rings
Publication date: Available online 10 July 2018Source: Computational and Theoretical ChemistryAuthor(s): He Lin, Dong-Dong Yang, Nan Lou, Shun-Guan Zhu, Hong-Zhen LiAbstractThe development of novel high energy density materials (HEDMs) with balanced detonation performance and sensitivity is a long-term goal in the energetic material field. In this work, by means of density functional theory, we systematically investigated physicochemical and energetic properties of three novel HEDMs constructed from furazan and piperazine frameworks with zero oxygen balance. Our results show that all these compounds have high densities (2....
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Valence Bond Structures for Molecules with 5-Electron 3- Centre Bonding Units
Publication date: Available online 30 June 2018Source: Computational and Theoretical ChemistryAuthor(s): Richard D. Harcourt, Thomas M. KlapötkeAbstractIt is shown how use of valence bond structures of the type for a 5-electron 3-centre bonding unit can help to provide compact valence bond representations of the electronic structures for NO2, N2O4, excited O3 and SO2, SO3, SO2Y2 (with Y = OH-, O- or F), ClO2, SO2-, S2O42-,[Cu(H2O)6]2+ and an N-H-N linkage. Without atomic valence shell expansions, many of these structures provide electronic interpretations for hypervalent 19th century type bond diagrams. As an example,...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Mechanistic Insights into the Chemoselectivity of PtCln (n = 2, 4)-Catalyzed O-H Insertion and Cyclopropanation Compared to Rh- and Cu-Catalyzed Reactions
This study is expected to improve the understanding of platinum-catalyzed reactions for the C-X bond construction and provide guidance for the future design of new catalysts and new reactions.Graphical abstract (Source: Computational and Theoretical Chemistry)
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Halogen Bonding in Self-Assembling Systems: A Comparison of Intra- and Interchain Binding Energies
Publication date: Available online 10 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Angelica P. Orlova, Paul G. JasienAbstractCalculations using the M06-2X and ωB97-XD density functionals with a triple-zeta quality polarized basis sets have been used to investigate the binding energies in a series of halogen bonded complexes of C2F4I2 with NC(CH2)nCN (n = 0-2). Results for complexes with monomer ratios from 1:1 to 3:3 indicate a near constant binding energies per halogen bond of ∼8 kJ/mol, ∼13 kJ/mol, and ∼14 kJ/mol for n = 0-2, respectively, indicating no observable cooperative effec...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Theoretical study on abnormal trans-effect of chloride, bromide and iodide ligands in iridium complexes
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Chen Wang, Yuan-Ye JiangAbstractIridium complexes have been widely applied to energy and chemical industry, pharmaceutical industry, and organic synthesis. As a parameter reflecting the interaction between ligands and metal centers, trans-effect plays an important role in the kinetics/thermodynamic stability, the reactivity and the catalytic performance of transition metal complexes. A systematic study was conducted herein to address the abnormal trans-effect of iridium halide complexes reported by Werneke et al. It is fo...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Diels-Alder cycloaddition versus ring-opening esterification: A computational study of the mechanism of formation of oxa-norbonene lactones from the reaction of furfuryl alcohol and itaconic anhydride
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Evans Fosu, Cecil Humphrey Botchway, Richard Tia, Evans AdeiAbstractThe reactions of furfuryl alcohol with itaconic anhydride can proceed via four plausible pathways – two pathways involving initial Diels-Alder cycloaddition followed by lactonization and two pathways involving initial esterification followed by intramolecular Diels-Alder cycloaddition – to afford two distinct norbornene products bearing either a five- or six-membered butyrolactone ring respectively. DFT calculations reported herein show that t...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Analytic calculation of ground state splitting in symmetric double well potential
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): A.E. SitnitskyAbstractThe exact solution of the one-dimensional Schrödinger equation with symmetric trigonometric double-well potential (DWP) is obtained via angular oblate spheroidal function. The results of stringent analytic calculation for the ground state splitting of ring-puckering vibration in the 1,3-dioxole (as an example of the case when the ground state tunneling doublet is well below the potential barrier top) and 2,3-dihydrofuran (as an example of the case when the ground state tunneling doublet is close...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Electronic Stark effect for a single molecule: Theoretical UV response
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Nalini D. Gurav, Shridhar P. Gejji, Rajeev K. PathakAbstractTheoretical analysis of optical absorption in the vacuum ultra-violet (VUV) region by single molecules placed in external electrostatic fields reveals characteristic absorption spectra completely at variance with their ‘zero-field’ counterparts consequent to appearance, disappearance, splitting, merging and shifts of absorption bands and extensive intensity redistributions. This ‘molecular electronic Stark effect’ can be tracked through el...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Nonlinear optical, IR and orbital properties of Ni doped MgO nanoclusters: A DFT investigation
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Ali Shokuhi Rad, Khurshid AyubAbstractIn the present study, density functional theory calculations have been performed to explore the changes in the electronic properties of Mg12O12 nanocluster through exohedral doping with nickel. The changes in zero-point Energies (ΔZPE), thermal Energies (ΔE), thermal Enthalpies (ΔH), and thermal Free Energies (ΔG) of all positions are also calculated and compared with interaction energies. The HOMO-LUMO gaps of Ni-doped MgO nanocages are reduced significantly m...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Mono substituted pyrenes as multifunctional materials for OLED: Analysis of the substituent effects on the charge transport properties using DFT methods
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Niveditha Surukonti, Bhanuprakash KotamarthiAbstractIn this work, with a general interest to understand the charge transport properties of mono substituted pyrene molecules which can be used as multifunctional materials in Organic Light Emitting Diodes (OLED), we have analyzed the charge transport properties calculated from DFT methods for a number of the mono substituted pyrene molecules whose crystal structures have been obtained from Cambridge structural data base (CSD). The data for the analysis was obtained by optimi...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Theoretical investigation of organotin(IV) complexes of substituted benzohydroxamic acids
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Richa Arora, Upasana Issar, Rita KakkarAbstractThe complexing abilities of para-substituted benzohydroxamates to the tin metal center of organotin(IV) ions have been investigated using DFT, since organotin(IV) compounds have been touted as promising anti-cancer agents. We have studied the coordination structures of Sn(IV) complexes (R2SnL2) with organoligands (R = Me, Et, n-Bu) and para-substituted benzohydroxamate ligands (L) so as to study the effect of electron withdrawing (Cl, F, NO2) and electron donating substit...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Study of gas-phase reactions within the modified Marcus model. II. CH3OH + CH3 → CH2OH + CH4
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): I.A. RomanskiiAbstractIn the framework of the Marcus theoretical model, using the intramolecular reorganization (IMR) method, the kinetics of the CH3OH + CH3 → CH2OH + CH4 reaction was studied over the temperature range of 10–550 K. The electronic activation energy (Ea) was calculated at the UCCSD(T)/6-31+G**//B3LYP/6–31+G** level. The calculation of the reaction rate constant, k, defined as the integral over the distance Q(C⋯C), was carried out on the assumption that for a hydrogen atom i...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Linear correlation between DSSC efficiency, intramolecular charge transfer characteristics, and NLO properties – DFT approach
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Dinesh S. Patil, Kiran C. Avhad, Nagaiyan SekarAbstractThe trends in the dye-sensitizer solar cells (DSSCs) efficiencies of 4 N, N-dimethylaniline-based polyene sensitizers, NKX-2553, NKX-2554, NKX-2600, and NKX-2569 have been correlated with the trends in intramolecular charge transfer characteristics as revealed by the trends in non-linear optical (NLO) properties. Both an electron-donor and π-linkers play a vital role in the performance of the sensitizer/dye in the DSSCs as well as in NLO properties. Optimized geo...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Thermodynamic selectivity of multicenter chemical reactions. A statistical quantification of a widespread intuitive approach and its application to reactions of fullerenes
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Denis Sh. Sabirov, Igor S. Shepelevich, Boris L. TumanskiiAbstractCurrently, there are many ways to estimate the selectivity of chemical reactions but none of them has the universal character. Therefore, novel approaches are introduced and developed. In the present study, we quantify a comparison of thermodynamic parameters of alternative reaction modes and propose the corresponding equation for thermodynamic selectivity describing the set of the one-type parallel reactions. It is defined as the ratio of the average diffe...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

The reactivity of coordinatively unsaturated iridium methylene complex IrCH2[N(SiMe2CH2PPh2)2]: A quantum chemistry study
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Zunyi Wu, Chuyue Xiang, Yutong Zhang, Zhijun Song, Qunfang Lei, Wenjun Fang, Hujun XieAbstractThe mechanisms for the reactions of the coordinatively unsaturated iridium methylene complex IrCH2[N(SiMe2CH2PPh2)2] with a variety of small molecules including H2, PMe3, CO, Al2Me6, and CH3I have been investigated by the density functional theory (DFT) calculations. The calculation results showed that the reaction of methylene complex with H2 generates the trihydride amine IrH3[HN(SiMe2CH2PPh2)2] via a series of oxidative additi...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Insight into interaction properties between mercury and lead cations with chitosan and chitin: Density functional theory studies
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): S. Jeremić, T.H. Tran, Z. Marković, T.C. Ngo, D.Q. DaoAbstractDensity functional theory (DFT) studies have contributed to analyze the interaction between chitosan and chitin with Hg(I), Hg(II) and Pb(I), Pb(II) ions in the absence or in the presence of one to three water molecules. All calculations were performed at the M06-2X/LanL2DZ level of theory using Glucosamine and N-acetylglucosamine monomers as models of chitosan and chitin biopolymers, respectively. Geometries of all complexes were optimized, enthalpies and Gi...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Novel method to detect the lung cancer biomarker volatiles using hydrogen vacant silicane nanosheets: A DFT investigation
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): V. Nagarajan, R. ChandiramouliAbstractUsing first-principles calculation, the electronic properties including geometrical stability of bare (BSi) and hydrogenated silicene (HSi) and hydrogen vacant silicane sheets (HvSi) are investigated. The geometrical stability of BSi, HSi and HvSi nanosheets are ensured in accordance with the formation energy and phonon band structure. The prime emphasis of the proposed work is to detect the exhaled human breath biomarkers and to detect the earlier stage of lung cancer disease using H...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Theoretical study of the mechanism and regioselectivity of the alkylation reaction of the phenoxide ion in polar protic and aprotic solvents
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Isac C. Nogueira, Josefredo R. PliegoAbstractAlkylation of the phenoxide ion in the solution phase can take place on the oxygen atom (O-alkylation) and the carbon atoms of the aromatic ring in the ortho- and para-positions (C-alkylation). The reaction outcome depends on the alkylating molecule and the solvent. This work presents a density functional theory calculation (X3LYP and M08-SO functionals) of the possible reaction pathways for alkylation of phenoxide ions with ethyl chloride in the following solvents: water, meth...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

DFT investigation of methane metathesis with L2AnCH3 actinide complexes catalysts (L = Cl, Cp, Cp*; An = Ac, Th, Pa, U, Np, Pu)
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Fazia Talbi-Ingrachen, Fatiha Talbi, Farida Kias, Aziz Elkechai, Abdou Boucekkine, Claude DaulAbstractIn order to understand the catalytic activity of the actinide complexes L2AnCH3 (An = Ac, Th, Pa, U, Np and Pu; L = Cl, Cp and Cp∗) towards the activation of the CH bond of methane, relativistic ZORA/DFT investigations have been carried out. The results obtained from Linear Transit (LT) and Intrinsic Reaction Coordinate (IRC) calculations show that the mechanism involved in these reactions starts with a pro...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

The computational probing of carrier transport in MAPbI3−xClx
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Kan Wang, Junxiang Xiang, Rai Nauman Ali, Bin Xiang, Xudong CuiAbstractMAPbI3−xClx (MA) perovskite has attracted much research attention because of its remarkable carrier transport performance. However, the influence of Cl incorporation in MAPbI3−xClx perovskite on the carrier transport performance still remains unclear. With the first-principles calculations, we found that with the incorporation of the small ionic radius of Cl−, it forces the orientation of MA molecule turning from diagonal direction to...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Kinetic effects in 2D and 3D quantum dots: Comparison between high and low electron correlation regimes
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Marlina Slamet, Viraht SahniAbstractKinetic related ground state properties of a two-electron 2D quantum dot in a magnetic field and a 3D quantum dot (Hooke’s atom) are compared in the Wigner high (HEC) and low (LEC) electron correlation regimes. The HEC regime corresponds to low densities sufficient for the creation of a Wigner molecule. The LEC regime densities are similar to those of natural atoms and molecules. The results are determined employing exact closed-form analytical solutions of the Schrödinger-Pa...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research

Key heptagon-containing metallofullerene intermediates in the LaSc2N@D5h(6)-C80 formation pathway: A theoretical study
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Fanhua Yin, Xin Liu, Kai TanAbstractEndohedral metallofullerene formation mechanisms have been proposed to involve insertion/extrusion of C2 fragment and Stone-Wales transformation (SWT). The isolation and crystallographic characterization of two isomeric LaSc2N@Ih(7)-C80 and LaSc2N@Cs(hept)-C80, which are closely related via a single step SWT, are reported to provide a clue for the trimetallic nitride template (TNT) formation pathway. Herein, we investigate three heptagon-containing isomers of LaSc2N@C80 by quantum chemi...
Source: Computational and Theoretical Chemistry - July 11, 2018 Category: Chemistry Source Type: research