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Theoretical Spectrograms (IR and Raman) have been constructed and compared with the experimental FT-IR and FT-Raman spectra. The effect of solvent polarity on the optimized structure is studied by the density functional theory calculation (LSDA, B3LYP, B3PW91 and MPW1PW91 with 6-311++G(d,p)) in gas phase and selected solvents benzene (non-polar sol...
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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal,...
The new hydrogen bonded molecular complex 1,2,4–triazolium hydrogenselenate (THS) is prepared by the reaction of 1H–1,2,4–triazole and selenic acid. This complex is stabilised by N–H⋯O and C–H⋯O hydrogen bonding and electrostatic attractive forces between 1H and 1,2,4–triazolium cations and hydrogen selenate anions. The XRD studies revealed that in...
The Fourier transform infrared (FT-IR) and FT-Raman of 1-methylnaphthalene (1MN) have been recorded and analyzed. The equilibrium geometry, bond lengths, bond angles and harmonic vibrational frequencies have been investigated with the help of density functional theory (DFT) method. Vibrational spectroscopic assignments of 1-methylnaphthalene (1MN)...
NiO is an excellent contender for smart windows, electrochemical super capacitor and dye sensitized photocathode. Hence, thin films of NiO with different concentrations (1, 3, 5 and 7 wt%) of Cr doping has been fabricated by a facile and low cost technique. The analysis of effect of Cr concentrations on structural, vibrational, morphological, optic...
In the present work, the authors have grown the bulk-sized single crystals of pure (Size ~ 45 × 10 × 10 mm3) and first time L-threonine (LT)-doped (Size ~ 85 × 10 × 8 mm3) KDP with high quality by Sankaranarayana-Ramasamy (SR) method in an aqueous solution at constant temperature. A remarkable enhancement in the growth rate was observed from 3.2 mm...
Citations
... The B3LYP functional is a hybrid functional that combines Becke's third parametrization for the exchange energy and the Lee, Yang and Parr functional for the correlation energy [17]. This functional has shown its efficiency for the calculation of many molecular properties [18]. The basis retained is the split-valence and double-dzeta 6-31G(d,p). ...
... Tiwari's group [82] [84], where bands at 922 (scaled at 937 cm À1 ) and 1294 (scaled at 1289 cm À1 ), cm À1 are assigned to b NÀC and n NÀC , respectively. A vibrational investigation on 2chloro-a-a-a trifluoro-3,5-dinitrotoluene using DFT is conducted by Gayathri and Arivazhagan [85]. It is shown an absorbance at 1055 (scaled at 1045 cm À1 ) and 1063 (scaled at 1062 cm À1 ) cm À1 due to NeC vibrational modes. ...
The surface interactions in [H-Pyr]+[HSO4]-/γ-Al2O3 system (prepared by wetness impregnation method) are investigated theoretically and experimentally. For that purpose, atoms in molecules theory, natural bond orbital and natural charge population analyses in a combination with a vibrational spectroscopy (FT-IR) are used. It is established that a bond formation between the hydrogen sulfate anion and the alumina influences the IL-support interaction in a great extent. However, a support-cation and a cation-anion interaction in the immobilized [H-Pyr]+[HSO4]- present as well. A comparative analysis between the experimental and the calculated vibrational modes is carried out and a significant number of infrared bands are assigned. The results indicate a good correlation between the experimental and the theoretical IR frequencies. It is found that the aforementioned interactions affected the vibrational frequencies in the supported IL.
... Vibrational spectroscopy is a popular approach in ILs studies since (i) internal rotation of various conformationally flexible groups of both cations and anions or possible movements of anions relative to cations are slow on the infrared spectroscopic timescales and (ii) hydrogen bonding is most straightforwardly exhibited in infrared spectra [19][20][21]. Density functional theory methods in combination with vibrational (FT-IR, Raman) and electronic (UV-vis) spectroscopies are widely used to investigate possible variants of molecular and electronic structure of different ILs [22][23][24]. For instance, the structure and interactions of a series of pyridinium-based ionic liquids composed of [C n Py] + cation (n = 2-14) and different anions ([Br] − , [BF 4 ] − , [NTf 2 ] − [PF 6 ] − ) were investigated using combined FT-IR spectroscopy and DFT at the B3LYP/6-311 ++G(d,p) level. ...
The molecular structure, vibrational frequencies of the fundamental modes and electronic transitions of the ionic liquid pyridinium nitrate ([H–Pyr] ⁺ [NO 3 ] ⁻ ) have been determined by means of density functional theory (DFT) at B3LYP/6-311++G (2d,2p) level. The chemical bonds nature and the intermolecular interactions in the title compound were investigated using the Quantum theory of atoms in molecules and Hirshfeld surface analysis. Natural bond orbital analysis has been performed in order to elucidate the hybridization and delocalization of electron density within the ion pair [H–Pyr] ⁺ [NO 3 ] ⁻ . A detailed vibrational spectral analysis was carried out and the assignments of the observed bands have been proposed on the basis of potential energy distribution. A good correlation between experimental and theoretical IR frequencies was observed. To study the charge transfers occurred in the title molecule, UV–vis analysis was conducted.
In order to improve the separation efficiency of copper and lead minerals, reduce the use of inhibitors, and further break the design bottleneck of the flotation collector, a novel compound with a di-minerophilic group was designed as a collector used for separating copper and lead minerals. In this study, novel oxadiazole-thione surfactants with or without a di-minerophilic group, including 5-methyl isobutylxanthate-1,3,4-oxadiazole-2-thione (MIXODT) and 5-heptyl-1,3,4-oxadiazole-2-thione (HpODT), were synthesized and introduced initially as collectors in flotation separation of chalcopyrite from galena. Micro-flotation indicated that MIXODT exhibited improved flotation ability and selectivity for chalcopyrite than HpODT. Meanwhile, DFT calculations also showed that the reactivity of MIXODT was higher than HpODT. The MIXODT's better selective adsorption behavior was characterized by wettability measurements, ζ-potential and UV spectra. The results of adsorption thermodynamic and kinetic experiments confirmed that MIXODT adsorption on chalcopyrite was an endothermic-spontaneous chemisorption process, with ΔH (change of enthalpy), ΔS (change of entropy), ΔG (change of free energy) and Ea (activation energy) values of 59.74 kJ•mol⁻¹, 274.70 J•mol⁻¹•K⁻¹, -23.02 kJ•mol⁻¹ and 58.68 kJ•mol⁻¹, respectively. The electrochemical behavior of the chalcopyrite surface showed that a dense adsorption layer was formed on the chalcopyrite surface after MIXODT treatment.
Helicene and its derivatives have received considerable attention as candidates for organic photoelectronic materials. Recently, novel quinoxaline-fused [7]carbohelicene derivatives have exhibited unique structural and photophysical properties, especially in the crystal state. However, their structure-property relationships have not been fully understood from their micromechanisms, which is also important to further improve their performance. Herein, the electronic transitions, electronic circular dichroism (CD), second-order nonlinear optical (NLO) responses and charge transport properties of five quinoxaline-fused [7]carbohelicene derivatives have been investigated based on density functional theory calculations. The experimental UV-Vis/CD spectra of the studied compounds were reproduced well by our calculations. Thus, we can assign their electron transition properties and absolution configurations (ACs) with high confidence. It is found that the CD bands of quinoxaline-fused [7]carbohelicene derivatives mainly originate from exciton coupling between quinoxaline, phenyl or 4-methoxyphenyl groups and [7]carbohelicene, which is in sharp contrast to [7]carbohelicene. More interestingly, these derivatives possess large first hyperpolarizability values. For example, the βHRS value of compound 6 is 32.96 × 10-30 esu, which is about 190 times larger than that of the organic urea molecule. The bandwidth of the valence band of compound 2 is comparable to that of the conduction band and slightly larger than that of tris(8-hydroxyquinolinato)aluminium. This means that compound 2 is a potential candidate as an ambipolar charge transport material. This journal is
