scholarly journals A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Binding Energies ◽  
Orbital Energy ◽  
Aminosalicylic Acid ◽  
Full Characterization

A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.

Electronic structure of on- and off-center hydrogenic impurities in quantum dots and quantum nanowires: energies and dipole polarizability

2018 ◽  
Vol 96 (10) ◽  
pp. 1104-1115 ◽  
Author(s):  
R.L.M. Melono ◽  
D. Dobgima ◽  
O. Motapon
Keyword(s):  
Quantum Dots ◽  
Electric Dipole ◽  
Energy Levels ◽  
Model Potential ◽  
Binding Energies ◽  
Dipole Polarizability ◽  
Cavity Radius ◽  
Quantum Size ◽  
Dipole Polarizabilities

The energy levels, ground state binding energies, and electric dipole polarizabilities of hydrogenic impurities in quantum dots and quantum nanowires have been investigated using a non-relativistic B-spline based variational method. Firstly, we have worked on the characterization of those impurities (donor/electron) in quantum dots and quantum nanowires, considering the two cases where the impurity is centered or off-centered in the nanostructure. Secondly, the electric dipole polarizabilities have been computed and their sensitivity with confinement parameters investigated. So the energies, binding energies, and dipole polarizabilities were reported for the centered and the off-centered donor and electron impurities as a function of the cavity radius and the off-center displacement. We found that the polarization of the studied system greatly depends on the model potential form, the off-center displacement, and the cavity radius. In the case of quantum dots and for the parabolic potential, the convergence of the polarizability for large values of the quantum size is shown. For the quantum nanowire case, we have shown that the polarizability is greater in the case of the z axis displacement than that of the transversal one. This leads to the fact that the system is more polarizable when the impurity is moved along the z axis than the transversal one.

First principle characterization of graphene shielding of the late transition metals: The role of coverage

2016 ◽  
Vol 30 (10) ◽  
pp. 1650108
Author(s):  
Zahra Vatankhah ◽  
Ali Kazempour
Keyword(s):  
Oxygen Adsorption ◽  
Binding Energies ◽  
Lower Probability ◽  
Graphene Monolayer ◽  
First Principle ◽  
First Principle Calculation ◽  
Late Transition Metals ◽  
Late Transition

Employing the first principle calculation, we investigate oxygen adsorption and incorporation into the subsurface of the graphene-coated Cu(111) considering various oxygen coverages. The obtained binding energies for different configurations reflect the fact that addition of graphene monolayer in both adsorptive and incorporative sites remarkably weakens the nature of binding, thus results in lower probability for oxygen permeation which is sensitive to the coverage. Additionally, comparison of potential averages of different mid-layer and over-layer graphene configurations confirms that graphene coating strongly increases the corrosion resistance of Cu surface in good agreement with available electrochemical measurements. Our results might be generalized and validated to designing new anti-corrosion coatings for other transition metal surfaces.

scholarly journals The role of heterogeneous lithology in a glaciofluvial deposit on unsaturated preferential flow – a numerical study

2017 ◽  
Vol 65 (3) ◽  
pp. 209-221 ◽  
Author(s):  
Erij Ben Slimene ◽  
Laurent Lassabatere ◽  
Jiří Šimůnek ◽  
Thierry Winiarski ◽  
Remy Gourdon
Keyword(s):  
Urban Areas ◽  
Hydraulic Properties ◽  
Preferential Flow ◽  
Numerical Study ◽  
Full Characterization ◽  
Capillary Barriers ◽  
Flow Pathways ◽  
Preferential Flow Pathways

AbstractAn understanding of preferential flow in the vadose zone is crucial for the prediction of the fate of pollutants. Infiltration basins, developed to mitigate the adverse effects of impervious surfaces in urban areas, are established above strongly heterogeneous and highly permeable deposits and thus are prone to preferential flow and enhanced pollutant transport. This study numerically investigates the establishment of preferential flow in an infiltration basin in the Lyon suburbs (France) established over a highly heterogeneous glaciofluvial deposit covering much of the Lyon region. An investigation of the soil transect (13.5 m long and 2.5 m deep) provided full characterization of lithology and hydraulic properties of present lithofacies. Numerical modeling with the HYDRUS-2D model of water flow in the transect was used to identify the effects of individual lithofacies that constitute the deposit. Multiple scenarios that considered different levels of heterogeneity were evaluated. Preferential flow was studied for several values of infiltration rates applied after a long dry period. The numerical study shows that the high contrast in hydraulic properties of different lithofacies triggers the establishment of preferential flow (capillary barriers and funneled flow). Preferential flow develops mainly for low water fluxes imposed at the surface. The role of individual lithofacies in triggering preferential flow depends on their shapes (layering versus inclusions) and their sizes. While lenses and inclusions produce preferential flow pathways, the presence of the surface layer has no effect on the development of preferential flow and it only affects the effective hydraulic conductivity of the heterogeneous transect.

scholarly journals Role of Molecular Orbital Energy Levels in OLED Performance

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rohit Ashok Kumar Yadav ◽  
Deepak Kumar Dubey ◽  
Sun-Zen Chen ◽  
Tzu-Wei Liang ◽  
Jwo-Huei Jou
Keyword(s):  
Molecular Orbital ◽  
Energy Levels ◽  
Orbital Energy ◽  
Molecular Orbital Energy ◽  
Oled Performance

Density Functional Theory Study of TinO2n-m Clusters (n=1-4, m=0,1)

2012 ◽  
Vol 507 ◽  
pp. 79-82
Author(s):  
Dong Mei Li ◽  
Zhi Hua Xiong ◽  
Qi Xin Wan
Keyword(s):  
Density Functional Theory ◽  
Oxygen Atom ◽  
Density Functional ◽  
Energy Levels ◽  
Binding Energies ◽  
Terminal Oxygen Atom ◽  
Functional Theory ◽  
Energy Gaps ◽  
Equilibrium Geometries ◽  
Oxygen Atoms

Using density functional theory, the equilibrium geometries of TinO2n and TinO2n-1 clusters (n=1-4) have been obtained. It suggests that the structures of these two corresponding clusters are changed slightly, except for the number of terminal oxygen atoms. The electronic properties have also been investigated. The bond between Ti and terminal oxygen atom is found to be more covalent than other Ti-O bonds. It also indicates that by deleting one terminal oxygen atom, HOMO is mainly derived from titanium atoms with least coordination, but not from singly-coordination oxygen atoms as that in the stoichiometric clusters. Highest energy levels of least-coordination Ti atoms shift highly and they become more reactive. In addition, HOMO-LUMO energy gaps and binding energies were observed. The calculated results show that the energy gaps decrease quickly, except for Ti4O7 clusters and all the binding energies are relatively large.

scholarly journals The role of molybdenum in suppressing cold dwell fatigue in titanium alloys

2017 ◽  
Vol 473 (2203) ◽  
pp. 20170189 ◽  
Author(s):  
Adam J. Ready ◽  
Peter D. Haynes ◽  
Blazej Grabowski ◽  
David Rugg ◽  
Adrian P. Sutton
Keyword(s):  
Density Functional Theory ◽  
Grain Size ◽  
Titanium Alloys ◽  
Density Functional ◽  
Binding Energies ◽  
Homogeneous Distribution ◽  
Functional Theory ◽  
Dwell Fatigue ◽  
Grain Orientations

We test a hypothesis to explain why Ti-6242 is susceptible to cold dwell fatigue (CDF), whereas Ti-6246 is not. The hypothesis is that, in Ti-6246, substitutional Mo-atoms in α-Ti grains trap vacancies, thereby limiting creep relaxation. In Ti-6242, this creep relaxation enhances the loading of grains unfavourably oriented for slip and they subsequently fracture. Using density functional theory to calculate formation and binding energies between Mo-atoms and vacancies, we find no support for the hypothesis. In the light of this result, and experimental observations of the microstructures in these alloys, we agree with the recent suggestion (Qiu et al. 2014 Metall. Mater. Trans. A 45 , 6075–6087. ( doi:10.1007/s11661-014-2541-5 )) that Ti-6246 has a much smaller susceptibility to CDF because it has a smaller grain size and a more homogeneous distribution of grain orientations. We propose that the reduction of the susceptibility to CDF of Ti-6242 at temperatures above about 200° C is due to the activation of 〈 c + a 〉 slip in ‘hard’ grains, which reduces the loading of grain boundaries.

scholarly journals Electronic structural properties of amino/hydroxyl functionalized imidazolium-based bromide ionic liquids

2020 ◽  
Vol 18 (1) ◽  
pp. 576-583
Author(s):  
Xiaoling Hu ◽  
Xingang Jia ◽  
Kehe Su ◽  
Xuefan Gu
Keyword(s):  
Ionic Liquids ◽  
Structural Properties ◽  
Density Functional ◽  
Energy Levels ◽  
Ion Pairs ◽  
Binding Energies ◽  
Intramolecular Interactions ◽  
Quantum Chemical Descriptors ◽  
Functional Theory ◽  
Chemical Descriptors

AbstractElectronic structural properties of the three different imidazolium-based ionic liquids, namely, 1-butyl-3-methyl imidazolium bromide (C4mimBr), 1-(4-hydroxybutyl)-3-methylimidazolium bromide (C4OHmimBr), and 1-(4-aminobutyl)-3-methylimidazolium bromide (C4NH2mimBr), were investigated with density functional theory at the B3LYP/6-311++G(d,p) level. The conformations of the mentioned cations were fully studied first using CONFLEX 8.A program. The quantum theory of atoms in molecules was used to investigate the nature of intramolecular interactions. The counterpoise-corrected ion pairs binding energies were obtained at the same level of theory. Natural bond orbital analyses show that the largest intra-molecular interaction comes from the orbital overlap between n(N1) and π* (N4–C5) in the mentioned compounds. The energy levels of frontier molecular orbitals (FMOs) are displayed. The global quantum chemical descriptors are also calculated based on the energy values of FMOs.

scholarly journals Cu(I) Arylsulfonate π-Complexes with 3-Allyl-2-thiohydantoin: The Role of the Weak Interactions in Structural Organization

2020 ◽  
Vol 67 (4) ◽  
pp. 1148-1154
Author(s):  
Andrii Fedorchuk ◽  
Evgeny Goreshnik ◽  
Yurii Slyvka ◽  
Marian Mys’kiv
Keyword(s):  
Coordination Compounds ◽  
Structural Organization ◽  
Weak Interactions ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
The Impact

The present work is directed toward preparation and structural characterization of two novel Cu(I) arylsulfonate π-complexes with 3-allyl-2-thiohydantoin, namely [Cu2(Hath)4](C6H5SO3)2 (1) and [Cu2(Hath)4](p-CH3C6H4SO3)2 · 2H2O (2) (Hath = 3-allyl-2-thiohydantoin), obtained by the means of alternating current electrochemical synthesis and studied with X-ray diffraction method. In both structures, the inner coordination sphere is represented by the cationic dimer [Cu2(Hath)4]2+ with one crystallographically independent copper(I) atom which has a trigonal pyramidal coordination environment formed by three Hath thiogroup S atoms and double C=C bond of its allyl group. [Cu2(Hath)4]2+ fragments in both coordination compounds are very similar, despite some divergences such as a big difference in Cu−S distance to the apical S atom (3.0374(8) Å in 1 and 2.7205(9) Å in 2). This difference was explained by the impact of the system of weak interactions, which are quite different.

scholarly journals Crystal structure of 4,4′-bis(4-bromophenyl)-1,1′,3,3′-tetrathiafulvalene

2019 ◽  
Vol 75 (8) ◽  
pp. 1195-1198 ◽  
Author(s):  
Sergei Rigin ◽  
Marina Fonari
Keyword(s):  
Title Compound ◽  
Density Functional ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Molecular Symmetry ◽  
Lumo Energy ◽  
Functional Theory ◽  
Compound C ◽  
Phenyl Rings ◽  
Homo Lumo

The molecule of the title compound, C18H10Br2S4, has a C-shape, with C s molecular symmetry. The dihedral angle between the planes of the dithiol and phenyl rings is 8.35 (9)°. In the crystal, molecules form helical chains along [001], the shortest interactions being π...S contacts within the helices. The intermolecular interactions were investigated by Hirshfeld surface analysis. Density functional theory (DFT) was used to calculate HOMO–LUMO energy levels of the title compound and its trans isomer.

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