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 10, 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 7, 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 6, 2018 Category: Chemistry Source Type: research

Effect of counterion on the reactivity, stability, aromaticity and charge distribution in mono- and polyphosphacyclopentadienide ions - A Theoretical Investigation
Publication date: Available online 3 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Angelina Mary, Raakhi GuptaAbstractThe effect of counterion (Li+, Na+ and K+) on π-charge distribution vis-a-vis aromaticity, chemical reactivity and stability of cyclopentadienide ion and its mono- and polyphospha-analogues has been investigated using the second-order Møller-Plesset (MP2) level of theory. The reactivity descriptors namely, chemical potential, electrophilicity index and chemical hardness based on LUMO, HOMO energy values are calculated at MP2/6-31++G(d,p) level. The aromaticity, thermochemistry...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

The Oxygen-atom Transfer Reactions of Mo-Diselenolene Biomimetic Complexes: A Computational Investigation
Publication date: Available online 5 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Eric A.C. BushnellAbstractThe aqueous Gibbs reaction and activation energies for the O-atom transfer mechanism of several Mo-bis(diselenolene) biomimetic complexes was investigated. The results obtained for the Mo-diselenolene biomimetic complexes were compared to analogous Mo-dithiolene biomimetic complexes to determine the effect of using Se-donor atoms vs. S-donor atoms. From the calculated value of ΔrG the exergonicty for the oxidation of sulfite is essentially unchanged with the substitution of the S-atoms wit...
Source: Computational and Theoretical Chemistry - July 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 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 6, 2018 Category: Chemistry Source Type: research

Computational modeling of the dinuclear metal complexes with di-o-quinones comprising paramagnetic acene linker groups
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Alyona A. Starikova, Vladimir I. MinkinAbstractThe magnetically-active dinuclear metal complexes with previously unstudied di-o-quinone ligands comprising paramagnetic acene linkers have been investigated with the use of density functional theory quantum-chemical calculations (UTPSSh/UB3LYP/6-311++G(d,p)). Two types of linker groups are considered: linear acenes comprising various number of six-membered cycles and polycyclic hydrocarbons containing terminal five-membered rings. In sodium complexes replacement of terminal ...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

Structure stability and electronic properties of PtmIrn (m + n = 2–7) clusters: A DFT study
Publication date: 15 August 2018Source: Computational and Theoretical Chemistry, Volume 1138Author(s): Kun Gao, Xiu-Rong Zhang, Zhi-Cheng Yu, Pei-Ying HuoAbstractStructure, stability and electronic properties of PtmIrn (m + n = 2–7) clusters have been systematically investigated by using density functional theory (DFT) with considering the generalized gradient approximation (GGA). The results reveal that the ground state structures change from planar to three-dimensional structures with the increase of the number of atoms, and Ir atoms play a decisive role in the formation of PtmIrn clusters. The addition of ...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

Vibrational and rotational excitation studies of the reaction Au+ + H2 → AuH+ + H using the time-dependent wave packet approach
Publication date: 1 September 2018Source: Computational and Theoretical Chemistry, Volume 1139Author(s): Jinghua Xu, Yong Zhang, Yu HanAbstractState-to-state dynamics calculations of the reaction Au+ + H2 with the initial states (v, j) = (0, 0), (0, 1), and (1, 0) were performed using the time-dependent wave packet method in the collision energy range from 2.0 to 4.5 eV. The reaction probabilities, integral cross sections (ICSs), and differential cross sections (DCSs) were calculated at the state-to-state level of theory. ICS results were compared with previous theoretical and experimental results, and present va...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

Dynamic first hyperpolarizability of trans- and cis-isomers of azobenzene chromophore DO3 calculated at DFT and MP2 levels
Publication date: 1 September 2018Source: Computational and Theoretical Chemistry, Volume 1139Author(s): Ilya V. Vasilyev, Olga D. Fominykh, Marina Yu. BalakinaAbstractBoth static and dynamic molecular quadratic nonlinear-optical characteristics of trans- and cis-isomers of azochromophore Disperse Orange, DO3, are studied by correlated MP2 technique and TD-DFT with two density functionals: meta-GGA M06-2X and range-separated ωB97X ones. The effect of solvent and radiation frequency on the first hyperpolarizability values is considered.All the tendencies obtained at the MP2 level are found to be valid at DFT level, th...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

Assessment of the performance of four dispersion-corrected DFT methods using optoelectronic properties and binding energies of organic monomer/fullerene pairs
In this study, we employ ωB97x-D, B97-D3, B3LYP-D3, and PBE1PBE-D3 and assess their accuracy by computing binding energies and electronic parameters (such as HOMO and LUMO eigenvalues) of the various (promising) molecular pairings of organic monomers and fullerenes. In addition, we employ time dependent DFT (TD-DFT) to determine optical properties of monomers such as their maximum absorption wavelengths and compare them with the experimental findings. Our results show that B97-D3 and B3LYP-D3 methods give the largest binding energies relative to the other D-DFT methods and they yield (relative to experimental values)...
Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research

Effect of counterion on the reactivity, stability, aromaticity and charge distribution in mono- and polyphosphacyclopentadienide ions - A Theoretical Investigation
Publication date: Available online 3 July 2018 Source:Computational and Theoretical Chemistry Author(s): Angelina Mary, Raakhi Gupta The effect of counterion (Li+, Na+ and K+) on π-charge distribution vis-a-vis aromaticity, chemical reactivity and stability of cyclopentadienide ion and its mono- and polyphospha-analogues has been investigated using the second-order Møller-Plesset (MP2) level of theory. The reactivity descriptors namely, chemical potential, electrophilicity index and chemical hardness based on LUMO, HOMO energy values are calculated at MP2/6-31++G(d,p) level. The aromaticity, thermochemistry, hyd...
Source: Computational and Theoretical Chemistry - July 3, 2018 Category: Chemistry Source Type: research

Valence Bond Structures for Molecules with 5-Electron 3- Centre Bonding Units
Publication date: Available online 30 June 2018 Source:Computational and Theoretical Chemistry Author(s): Richard D. Harcourt, Thomas M. Klapötke It 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, SO2 Y 2 (with Y = OH-, O- or F), ClO2, SO2 -, S2O4 2-,[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 - June 30, 2018 Category: Chemistry Source Type: research

Vibrational and rotational excitation studies of the reaction Au+  + H2 → AuH+ + H using the time-dependent wave packet approach
Publication date: 1 September 2018 Source:Computational and Theoretical Chemistry, Volume 1139 Author(s): Jinghua Xu, Yong Zhang, Yu Han State-to-state dynamics calculations of the reaction Au+ + H2 with the initial states (v, j) = (0, 0), (0, 1), and (1, 0) were performed using the time-dependent wave packet method in the collision energy range from 2.0 to 4.5 eV. The reaction probabilities, integral cross sections (ICSs), and differential cross sections (DCSs) were calculated at the state-to-state level of theory. ICS results were compared with previous theoretical and experimental results, and present values ...
Source: Computational and Theoretical Chemistry - June 28, 2018 Category: Chemistry Source Type: research

Dynamic first hyperpolarizability of trans- and cis-isomers of azobenzene chromophore DO3 calculated at DFT and MP2 levels
Publication date: 1 September 2018 Source:Computational and Theoretical Chemistry, Volume 1139 Author(s): Ilya V. Vasilyev, Olga D. Fominykh, Marina Yu. Balakina Both static and dynamic molecular quadratic nonlinear-optical characteristics of trans- and cis-isomers of azochromophore Disperse Orange, DO3, are studied by correlated MP2 technique and TD-DFT with two density functionals: meta-GGA M06-2X and range-separated ωB97X ones. The effect of solvent and radiation frequency on the first hyperpolarizability values is considered. All the tendencies obtained at the MP2 level are found to be valid at DFT level, the fi...
Source: Computational and Theoretical Chemistry - June 28, 2018 Category: Chemistry Source Type: research

Structure stability and electronic properties of PtmIrn (m  + n = 2–7) clusters: A DFT study
Publication date: 15 August 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): Kun Gao, Xiu-Rong Zhang, Zhi-Cheng Yu, Pei-Ying Huo Structure, stability and electronic properties of Pt m Ir n (m + n = 2–7) clusters have been systematically investigated by using density functional theory (DFT) with considering the generalized gradient approximation (GGA). The results reveal that the ground state structures change from planar to three-dimensional structures with the increase of the number of atoms, and Ir atoms play a decisive role in the formation of Pt m Ir n clusters. The addition of...
Source: Computational and Theoretical Chemistry - June 27, 2018 Category: Chemistry Source Type: research

Structure stability and electronic properties of PtmIrn (m+n=2 ∼7) clusters: A DFT study
Publication date: Available online 23 June 2018 Source:Computational and Theoretical Chemistry Author(s): Gao Kun, Zhang Xiu-Rong, Yu Zhi-Cheng, Huo Pei-Ying Structure, stability and electronic properties of Pt m Ir n (m+n = 2∼7) clusters have been systematically investigated by using density functional theory (DFT) with considering the generalized gradient approximation (GGA). The results reveal that the ground state structures change from planar to three-dimensional structures with the increase of the number of atoms, and Ir atoms play a decisive role in the formation of Pt m Ir n clusters. The addition of a small a...
Source: Computational and Theoretical Chemistry - June 23, 2018 Category: Chemistry Source Type: research

Dynamic first hyperpolarizability of trans- and cis- isomers of Azobenzene Chromophore DO3 calculated at DFT and MP2 levels
Publication date: Available online 23 June 2018 Source:Computational and Theoretical Chemistry Author(s): Ilya V. Vasilyev, Olga D. Fominykh, Marina Yu. Balakina Both static and dynamic molecular quadratic nonlinear-optical characteristics of trans- and cis-isomers of azochromophore Disperse Orange, DO3, are studied by correlated MP2 technique and TD-DFT with two density functionals: meta-GGA M06-2X and range-separated ωB97X one. The effect of solvent and radiation frequency on the first hyperpolarizability values is considered. All the tendencies obtained at the MP2 level are found to be valid at DFT level, the fir...
Source: Computational and Theoretical Chemistry - June 23, 2018 Category: Chemistry Source Type: research

Vibrational and Rotational Excitation Studies of the Reaction Au+ + H2 → AuH+ + H Using the Time-Dependent Wave Packet Approach
Publication date: Available online 20 June 2018 Source:Computational and Theoretical Chemistry Author(s): Jinghua Xu, Yong Zhang, Yu Han State-to-state dynamics calculations of the reaction Au+ + H2 with the initial states (v, j) = (0, 0), (0, 1), and (1, 0) were performed using the time-dependent wave packet method in the collision energy range from 2.0 to 4.5 eV. The reaction probabilities, integral cross sections (ICSs), and differential cross sections (DCSs) were calculated at the state-to-state level of theory. ICS results were compared with previous theoretical and experimental results, and present values are in goo...
Source: Computational and Theoretical Chemistry - June 21, 2018 Category: Chemistry Source Type: research

The computational probing of carrier transport in MAPbI3 −xClx
Publication date: 15 August 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): Kan Wang, Junxiang Xiang, Rai Nauman Ali, Bin Xiang, Xudong Cui MAPbI3−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 axia...
Source: Computational and Theoretical Chemistry - June 21, 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 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): Fazia Talbi-Ingrachen, Fatiha Talbi, Farida Kias, Aziz Elkechai, Abdou Boucekkine, Claude Daul In 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 proton t...
Source: Computational and Theoretical Chemistry - June 21, 2018 Category: Chemistry Source Type: research

Key heptagon-containing metallofullerene Intermediates in the LaSc2N@D5h(6)-C80 formation pathway: A Theoretical Study
Publication date: Available online 19 June 2018 Source:Computational and Theoretical Chemistry Author(s): Fanhua Yin, Xin Liu, Kai Tan Endohedral 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@I h (7)-C80 and LaSc2N@C s (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 chem...
Source: Computational and Theoretical Chemistry - June 20, 2018 Category: Chemistry Source Type: research

The computational probing of carrier transport in MAPbI3-xClx
Publication date: Available online 18 June 2018 Source:Computational and Theoretical Chemistry Author(s): Kan Wang, Junxiang Xiang, Rai Nauman Ali, Bin Xiang, Xudong Cui MAPbI3-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 axial direction. As ...
Source: Computational and Theoretical Chemistry - June 19, 2018 Category: Chemistry Source Type: research

Computational modeling of the dinuclear metal complexes with di-o-quinones comprising paramagnetic acene linker groups
Publication date: Available online 18 June 2018 Source:Computational and Theoretical Chemistry Author(s): Alyona A. Starikova, Vladimir I. Minkin The magnetically-active dinuclear metal complexes with previously unstudied di-o-quinone ligands comprising paramagnetic acene linkers have been investigated with the use of density functional theory quantum-chemical calculations (UTPSSh/UB3LYP/6-311++G(d,p)). Two types of linker groups are considered: linear acenes comprising various number of six-membered cycles and polycyclic hydrocarbons containing terminal five-membered rings. In sodium complexes replacement of terminal six...
Source: Computational and Theoretical Chemistry - June 19, 2018 Category: Chemistry Source Type: research

Assessment of the Performance of Four Dispersion-Corrected DFT Methods Using Optoelectronic Properties and Binding Energies of Organic Monomer/Fullerene Pairs
In this study, we employ ω B97x-D, B97-D3, B3LYP-D3, and PBE1PBE-D3 and assess their accuracy by computing binding energies and electronic parameters (such as HOMO and LUMO eigenvalues) of the various (promising) molecular pairings of organic monomers and fullerenes. In addition, we employ time dependent DFT (TD-DFT) to determine optical properties of monomers such as their maximum absorption wavelengths and compare them with the experimental findings. Our results show that B97-D3 and B3LYP-D3 methods give the largest binding energies relative to the other D-DFT methods and they yield (relative to experimental values...
Source: Computational and Theoretical Chemistry - June 19, 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 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): V. Nagarajan, R. Chandiramouli Using 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 HvSi b...
Source: Computational and Theoretical Chemistry - June 19, 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 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): Zunyi Wu, Chuyue Xiang, Yutong Zhang, Zhijun Song, Qunfang Lei, Wenjun Fang, Hujun Xie The 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 addition an...
Source: Computational and Theoretical Chemistry - June 19, 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: Available online 15 June 2018 Source:Computational and Theoretical Chemistry Author(s): Isac C. Nogueira, Josefredo R. Pliego Alkylation 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, methano...
Source: Computational and Theoretical Chemistry - June 16, 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 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): I.A. Romanskii In 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 in th...
Source: Computational and Theoretical Chemistry - June 16, 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: Available online 14 June 2018 Source:Computational and Theoretical Chemistry Author(s): Fazia Talbi-Ingrachen, Fatiha Talbi, Farida Kias, Aziz Elkechai, Abdou Boucekkine, Claude Daul In 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 C–H 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 proton ...
Source: Computational and Theoretical Chemistry - June 15, 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: Available online 14 June 2018 Source:Computational and Theoretical Chemistry Author(s): S. Jeremić, T.H. Tran, Z. Marković, T.C. Ngo, D.Q. Dao Density 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 Gibbs...
Source: Computational and Theoretical Chemistry - June 15, 2018 Category: Chemistry Source Type: research

Linear Correlation Between DSSC Efficiency, Intramolecular Charge Transfer Characteristics, and NLO Properties – DFT Approach
Publication date: Available online 15 June 2018 Source:Computational and Theoretical Chemistry Author(s): Dinesh S. Patil, Kiran C. Avhad, Nagaiyan Sekar The 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 geometri...
Source: Computational and Theoretical Chemistry - June 15, 2018 Category: Chemistry Source Type: research

Theoretical investigation of organotin(IV) complexes of substituted benzohydroxamic acids
Publication date: 15 August 2018 Source:Computational and Theoretical Chemistry, Volume 1138 Author(s): Richa Arora, Upasana Issar, Rita Kakkar The 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 substituents...
Source: Computational and Theoretical Chemistry - June 14, 2018 Category: Chemistry Source Type: research