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Journal of Physical Chemistry. A

Shohei Ohtomi, Masamitsu Hoshino, Atsushi Suga, Hidetoshi Kato, Denis Duflot, Paulo Limao-Vieira, Hiroshi Tanaka
Electron energy loss (EEL) spectra of GeF4 have been measured with incident electrons at 100 eV for 5° scattering angle and at 30 eV for 30° scattering angle, while sweeping the energy loss over the range 7.0-21.0 eV. Low-lying excited triplet, singlet, valence and Rydberg states are investigated and the assignments supported by quantum chemical ab initio calculations. This provides the first comprehensive investigation of all singlet and triplet excited electronic states of germanium tetrafluoride up to the first ionisation energy...
October 26, 2016: Journal of Physical Chemistry. A
Nelly Bonifaci, Zhiling Li, Jussi Eloranta, Steven L Fiedler
The interaction potentials of the He(*)(2) excimer, in the a (3)Σu, b (3)Πg, c (3)Σg , and d (3)Σu electronic states with a ground state helium atom are presented. The symmetry of the interaction potentials closely follows the excimer Rydberg electron density with pronounced short-range minima appearing along the nodal planes of the Rydberg orbital. In such cases, a combination of the electrostatic short-range attraction combined with Pauli repulsion leads to the appearance of unusual long-range maxima in the potentials...
October 26, 2016: Journal of Physical Chemistry. A
Omer Kirshenboim, Sebastian Kozuch
Halogen bonds (XB) are no longer newcomers in the chemistry family. However, XB in hypervalent halogens has not been thoroughly studied. We provide a molecular orbital explanation of the shape and strength of XBs in hypervalent halogens and other species, focusing on the charge transfer and electrostatic aspects of these bonds. Our results show that σ-holes (and subsequently the XBs associated with them) can be easily divided and bent by the influence of equatorial substituents. Inductive effect of both the equatorial and axial groups can affect these distortions, but also the angle between the equatorial ligands has a large influence on the shape of the σ-holes and the molecular orbitals acting as electron acceptor...
October 26, 2016: Journal of Physical Chemistry. A
Ana Martínez
In this investigation, the feasibility of functionalizing fullerene and bismullene with Bi and C as intruders is theoretically explored. The systems analyzed are C60-xBix (with x = 0-10, fullerene-like) and Bi60-yCy (with y = 0-10, bismullene-like). Optimized geometries, reactivity indexes, and highest occupied molecular orbital to lowest unoccupied molecular orbital (HOMO-LUMO) gaps (for analyzing the potential application of these molecules as materials for solar cells) are reported. The most stable structures of bismullene-like systems have cage geometries...
October 25, 2016: Journal of Physical Chemistry. A
Christina Bagwill, Christa Anderson, Elizabeth Sullivan, Varun Manohara, Prithvi Murthy, Charles C Kirkpatrick, Apryll M Stalcup, Michael Adam Lewis
A computational study aimed at accurately predicting the strength of the anion-π binding of substituted benzenes is presented. The anion-π binding energies (Ebind) of 37 substituted benzenes, and the parent benzene, with chloride or bromide were investigated at the MP2(full)/6-311++G** level of theory. In addition, energy decomposition analysis was performed on 27 selected chloride-arene complexes via Symmetry Adapted Perturbation Theory (SAPT), using the SAPT2+ approach. Initial efforts aimed to correlate the anion-π Ebind values with the sum of the Hammett constants σp (Σσp) or σm (Σσm), as done by others...
October 25, 2016: Journal of Physical Chemistry. A
Matthias Wohlgemuth, Roland Mitric
We introduce a general theoretical approach for the simulation of photochemical dynamics under the influence of circularly polarized light in order to explore the possibility of generating enantiomeric enrichment through polarized-light-selective photochemistry. The method is applied to the simulation of the photolysis of alanine, a prototype chiral amino acid. We show that a systematic enantiomeric enrichment can be obtained depending on the helicity of the circularly polarized light that induces the excited state photochemistry of alanine...
October 25, 2016: Journal of Physical Chemistry. A
Zhe Zeng, Mohammednoor Altarawneh, Ibukun Oluwoye, Peter Glarborg, Bogdan Z Dlugogorski
This study resolves the interaction of sulfanyl radical (SH) with aliphatic (C1-C4) hydrocarbons, using CBS-QB3 based calculations. We obtained the C-H dissociation enthalpies and located the weakest link in each hydrocarbon. Subsequent computations revealed that, H abstraction by SH from the weakest C‒H sites in alkenes and alkynes, except for ethylene, appears noticeably exothermic. Furthermore, abstraction of H from propene, 1-butene and iso-butene displays pronounced spontaneity (i.e., ΔrG° < -20 kJ mol-1 between 300 - 1200 K) due to the relatively weak allylic hydrogen bond...
October 25, 2016: Journal of Physical Chemistry. A
Antonia G Zogka, Abdelwahid Mellouki, Manolis N Romanias, Yuri Bedjanian, Mahmoud Idir, Benoit Grosselin, Veronique Daele
The rate coefficients for the reactions of OH and Cl with 1-methoxy 2-propyl acetate (MPA) in the gas phase were measured using absolute and relative methods. The kinetic study on the OH-reaction was conducted in the temperature (263-373) K and pressure (1-760) Torr ranges using the pulsed laser photolysis-laser induced fluorescence technique, a low pressure fast flow tube reactor-quadrupole mass spectrometer and an atmospheric simulation chamber-GC/FID. The derived Arrhenius expression is kMPA+OH(T)=(2.01±0...
October 24, 2016: Journal of Physical Chemistry. A
Aaron D Bailey, Bryan P Murphy, Hairong Guan
An efficient synthesis of a green dye from oxidative coupling of p-phenylenediamine (PPD) and resorcinol (in a 2:1 ratio) has been developed. Reactivity studies of this dye molecule with a variety of reagents (PPD, resorcinol, the oxidized form of the green dye itself, and a dinuclear indo dye) demonstrate that it cannot be the key reactive intermediate in reported oxidative oligomerization of PPD and resorcinol. However, the trinuclear species does form large aggregates. At least one viable pathway of oligomerization has been demonstrated with the dinuclear indo dye...
October 24, 2016: Journal of Physical Chemistry. A
Wan-Yi Li, Xia Li, Steffen Jockusch, Han Wang, Bolei Xu, Yajing Wu, William Gang Tsui, Hai-Lung Dai, V Faye McNeill, Yi Rao
Photoactivated reactions of organic species in atmospheric aerosol particles are a potentially significant source of secondary organic aerosol material (SOA). Despite recent progress, the dominant chemical mechanisms and rates of these reactions remain largely unknown. In this work, we characterize the photo-physical properties and photochemical reaction mechanisms of imidazole-2-carboxaldehyde (IC) in aqueous solution, alone and in the presence of isoprene. IC has been shown previously in laboratory studies to participate in photoactivated chemistry in aerosols, and is a known in-particle reaction product of glyoxal...
October 24, 2016: Journal of Physical Chemistry. A
Jinchun Qiu, Daniel K Unruh, Anthony Frank Cozzolino
Density Functional Theory calculations were used to design an anion receptor that utilizes antimony(III) secondary bonding interactions. Calculations were performed on promising motifs found in the chemical literature where two antimony sites were found in close proximity to a halide anion. The study was extended to a structurally related class of 1,3,2-benzodioxastibole derivatives to elucidate their potential for binding halide ions. Multiple geometric conformations were evaluated and various ratios of halide anions were considered...
October 21, 2016: Journal of Physical Chemistry. A
Maria Demireva, JungSoo Kim, P B Armentrout
Guided ion beam mass spectrometry (GIBMS) is used to measure the kinetic energy dependent product ion cross sections for reactions of the lanthanide metal gadolinium cation (Gd(+)) with O2, CO2, and CO and for reactions of GdO(+) with CO, O2, and Xe. GdO(+) is formed through barrierless and exothermic processes in the reactions of Gd(+) with O2 and CO2. All other reactions observed are endothermic, and analyses of their kinetic energy dependent cross sections yield 0 K bond dissociation energies (BDEs) for GdO(+), GdC(+), and GdCO(+)...
October 21, 2016: Journal of Physical Chemistry. A
Xiaoting Liu, Dandan Shi, Shimin Shan, Peiyuan Yan, Haifeng Xu, Bing Yan
High-level ab initio calculations on the ground and the excited states of aluminum monobromide (AlBr) have been carried out by utilizing the internally contracted multi-reference configuration interaction method plus Davidson correction (icMRCI+Q) method. The core-valence correlation (CV) correction and spin-orbit coupling (SOC) effect have been investigated in the calculations. The potential energy curves (PECs) of the 13 Λ-S states, as well as those of the 24 Ω states generated from the Λ-S states under the SOC effect, have been obtained...
October 21, 2016: Journal of Physical Chemistry. A
Yu Harabuchi, Rina Yamamoto, Satoshi Maeda, Satoshi Takeuchi, Tahei Tahara, Tetsuya Taketsugu
Ab initio molecular dynamics (AIMD) simulations were carried out for *-excited 1,1'-dimethylstilbene (dmSB) at the spin-flip time-dependent density functional theory (SF-TDDFT) level with the TSF-index technique, to get insights into the substitution effects on the photoisomerization dynamics of stilbene (SB). It is found that the reaction path from the Franck-Condon structure of cis-dmSB is oriented toward the 4,4-dihydrophenanthrene (DHP) side from the beginning, which is in contrast to the case of SB where the pathway is oriented toward the twist-side in the initial stage...
October 21, 2016: Journal of Physical Chemistry. A
Alessandra Souza Barbosa, Filipe Ferreira da Silva, Andre Rebelo, Søren Vrønning Hoffmann, Marcio H F Bettega, Paulo Limao-Vieira
Here we report novel comprehensive investigations on the electronic state spectroscopies of isolated 2,4- and 2,6-difluorotoluene in the gas phase by high-resolution vacuum ultraviolet (VUV) photoabsorption measurements in the 4.4-10.8 eV energy-range, with absolute cross-section values derived. We also present the first set of ab initio calculations (vertical energies and oscillator strengths), which we have used in the assignment of valence transitions of the difluorotoluene molecules, together with calculated ionisation energies to obtain the Rydberg transitions for both molecules...
October 21, 2016: Journal of Physical Chemistry. A
Tiecheng Zhou, Joshua J Goings, Zhou Lin
No abstract text is available yet for this article.
October 21, 2016: Journal of Physical Chemistry. A
Andrei V Nikitin, Michael Rey, Alena Alexandrovna Rodina, Balasubramoniam Murali Krishna, Vladimir G Tyuterev
Nine-dimensional potential energy surface (PES) and dipole moment surface (DMS) of the germane molecule are constructed using extended ab initio CCSD(T) calculations at 19882 points. PES analytical representation is determined as an expansion in non-linear symmetry adapted products of orthogonal and internal coordinates involving 340 parameters up to 8th order. Minor empirical refinement of the equilibrium geometry and of four quadratic parameters of the PES computed at the CCSD(T) / aug-cc-pVQZ-DK level of the theory yielded the accuracy below 1 cm-1 for all experimentally known vibrational band centers of five stable isotopologues of 70GeH4, 72GeH4, 73GeH4, 74GeH4 and 76GeH4 up to 8300 cm-1...
October 20, 2016: Journal of Physical Chemistry. A
Cercis Morera-Boado, Marco Martínez González, Ramon Alain Miranda-Quintana, Margarita Suarez, Roberto Martinez-Alvarez, Nazario Martín, Jose M Garcia de la Vega
The retro-cycloaddition thermal reaction of isoxazolino[4,5:1,2][60]fullerenes to pristine fullerene seems to be guided by the electronic nature of the substituted nitrile oxide 1,3-dipole in the isoxazoline ring. Trapping experiments proved that the reaction mechanism occurs by thermal removal of the nitrile oxide 1,3-dipole in a process that is favored in the presence of a big excess of a highly efficient dipolarophile, such as maleic anhydride. Theoretical gas phase calculations carried out at the B3LYP/6-31G(d) and M06-2X/6-31G(d) levels of theory underpin the experimental findings and predict that compound 1c, bearing the p-(CH3)2N-Ph substituent on the isoxazoline ring and with an experimental remarkable conversion efficiency in just 12 hours, showed the lowest activation energies...
October 20, 2016: Journal of Physical Chemistry. A
Hui-Hsu Gavin Tsai, Jia-Cheng Hu, Chun-Jui Tan, Yung-Ching Sheng, Chih-Chiang Chiu
The loading of dye sensitizers on a semiconductor is crucial for determining the light harvesting efficiency of dye-sensitizer solar cells (DSSCs). The interfacial properties of dyes adsorbed on TiO2 film such as adsorption configurations and adsorption energy can influence the total amount of dye sensitizers that loads and the stability of a DSSC device. Therefore, it is important to characterize the adsorption properties of dye sensitizers on TiO2 film atomically and electronically to ensure rational structure-based dye design for high-performance DSSCs...
October 20, 2016: Journal of Physical Chemistry. A
Debojit Bhattacharya, Suranjan Shil, Anirban Misra, Laimutis Bytautas, Douglas J Klein
Here we study a set of novel magnetic organic molecular species with different halide ions (fluoride, chloride, bromide) absorbed ~2Å above or below the center of an aromatic π-ring in an m-aminyl diradical. Focus is on the nature of anion-π interaction and its impact on magnetic properties, specifically on magnetic anisotropy and on intramolecular magnetic exchange coupling. In the development of single molecule magnets, magnetic anisotropy is considered to be the most influential factor. A new insight regarding the magnetic anisotropy which determines the barrier height for relaxation of magnetization of m-aminyl diradical-derived anionic complexes is obtained from calculations of the axial Zero-Field-Splitting (ZFS) parameter D...
October 20, 2016: Journal of Physical Chemistry. A
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