Experimental and theoretical study of a novel synthesized thiophene compound (original) (raw)
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ACTA PHYSICA POLONICA A, 2017
Vibrational frequencies of 2-Amino-4,5,6,7- Tetrahydrobenzo[b]Thiophene-3-Carbonitrile were calculated using density functional (DFT/B3YLP) method with 6-311++G(d,p) basis set by Gaussian 09. The assignments of the vibrational frequencies have been done by potential energy distribution analysis, using VEDA 4 software. The density functional theory and time dependent density functional theory methods have been used to study the electronic properties of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital method. All computed spectroscopic properties were compared with experimental ones. The simulated spectra of the molecule show excellent agreement with the experimental spectra.
Journal of Molecular Structure: THEOCHEM, 2009
The DFT-B3LYP method has been used for the ground-state (S0) geometry optimization of two novel compounds, 2-dicyanovinyldithieno[2,3-b:3′,2′-d]thiophene (DCST) and 2-dicyanovinyldithieno[3,2-b:2′,3′-d]thiophene (DCTT). The CASSCF approach has also been used to optimize the S0 and S1 electronic states of their more stable isomers, DCST 1 and DCTT 2. The absorption spectra of DCST and DCTT have been investigated at the TD-B3LYP/cc-pVTZ level,
Journal of Molecular Structure, 2001
The equilibrium molecular geometry of thiophene has been determined from a combination of gas-phase electron diffraction, vibrational and microwave data and ab initio and DFT calculations. The quadratic and cubic force constants of thiophene calculated theoretically and empirically improved by harmonic scale factors were incorporated in the analysis in which equilibrium distances and harmonic scale factors were re®ned simultaneously. The diffraction intensities were calculated by the use of ®rst-order perturbation theory. The commonly used r a distances and amplitudes of vibration were also estimated and found to agree reasonably well with those from an earlier investigation. Anharmonic phase shift parameters for all atom pairs and the various distance correction terms are presented. q
Spectroscopic and density functional theory study of functionalized thiophene-benzene derivatives
Journal of Raman Spectroscopy, 2005
A group of diethenylbenzene-linked oligothiophenes were investigated using vibrational spectroscopy in conjunction with quantum calculations. Geometry calculations revealed dihedral angles that are sensitive to both the presence of cyano substituents on the ethylene linkages and the identity of the attached oligothiophene. In particular, cyano substitution in the presence of terthiophene groups leads to a significant loss of planarity. The resultant loss of conjugation has been observed in the experimental Raman spectra on the basis of a band at ∼1520 cm −1 , the wavenumber and intensity of which are dependent on conjugation length. In the case of the diethenylbenzene-linked terthiophene, the wavenumber of this band suggests a conjugation that extends across both terthiophene and the diethenylbenzene species. The calculated vibrational spectra successfully predict the wavenumber shifts upon cyano substitution in both the infrared and Raman spectra. The presence of the cyano groups has the greatest influence on the Mulliken charge distribution, whereas the identity of the oligothiophene has little effect. This study shows that quantum calculations, particularly when combined with experimental parameters such as vibrational spectroscopy, can be informative in understanding the electronic structure of molecules of this type.
ChemInform Abstract: Studies in the Dithienylbenzo[c]thiophene Series
ChemInform, 1998
A number of derivatives of 1,3-dithienylbenzo[c]thiophene have been synthesized. The mono-and dicarboxaldehydes have been elaborated to give new vinylenes and cyanovinylenes. -Dodecyland hexyl-substituted analogues have been prepared. Results from cyclic voltammetric investigation as well as fluorescence studies are reported. Scheme 1 3105 Scheme 6 Scheme 7
Studies in the Dithienylbenzo[ c ]thiophene Series
The Journal of Organic Chemistry, 1998
A number of derivatives of 1,3-dithienylbenzo[c]thiophene have been synthesized. The mono-and dicarboxaldehydes have been elaborated to give new vinylenes and cyanovinylenes. -Dodecyland hexyl-substituted analogues have been prepared. Results from cyclic voltammetric investigation as well as fluorescence studies are reported. Scheme 1 3105 Scheme 6 Scheme 7
Journal of Applied …, 2009
Heterocyclic conjugated oligomers, especially those from thiophene family have been widely studied for 10 years due to their excellent electronic, optical and electronic properties . Oligothiophenes are a promising class of semi-conductors and many of them have been employed in Light -emitting diodes , as well as in p-channel FETs [6-8]. On the other hand the oligomers based on mixed heterocyclic compounds in which electron-donating units coexist with electron-withdrawing ones in the polymer main chain were studied [7]. 1.4.4oxadiaozole considered as an important five-membred compound among the large heterocyclic families, has been studied as excellent candidate for material applications during the past years due to its excellent thermal, chemical stabilities and high photoluminescence quantum yields [8]. Numerous examples of oxadiazole-based compound have been applied as electrontransporting materials [9] in OLEDS. On the other hand, examples of 1, 3, 4-oxadiaozole Abstract Theoretical study on the geometries and electronic properties of new conjugated compound based on thiophene and oxadiazole was carried out. The theoretical ground-state geometry and electronic structure of the studied molecules were obtained by the DFT method at B3LYP level with 6-31G (d) basis set. The electronic properties were determined by ZINDO/s, CIS/6-31G (d) and TD//B3LYP/6-31G (d) calculations were performed on the B3LYP/6-31(d) optimized geometries. The effects of the ring structure and the substituents on the geometries and electronic properties of these materials are discussed. The results of this study demonstrated how the electronic properties can be tuned by the backbone ring or side group and suggest these compounds as good candidates for opto-electronic applications.
2017
In the present work, the quantum theoretical calculations of the molecular structure of the 1-(1, 3-Benzothiazol-2-yl)-3-(thiophene-5-carbonyl) thiourea has been predicted and are evaluated using Density Functional Theory (DFT) in gas phase. The geometry of the title compound was optimized by B3LYP/6-311+G and B3LYP/6-311+G* methods and the experimental geometrical parameters of the title compound such as bond lengths (A), bond angles (°) and torsion angels (°) were compared with calculated results. The theoretical 1H and 13C NMR chemical shift (GIAO method) values of the title compound are calculated and compared with the experimental results. The computed data are in good agreement with the experimental data. Frontier molecular orbitals (FMOs) such as HOMO orbital, LUMO orbital and HOMO-LUMO energy gap, molecular electrostatic potential (MEP), electronic properties such as ionization potential, electron affinity, global hardness, electronegativity, electronic chemical potential, e...
Journal of Molecular Structure, 2010
The 1-(4-(4-Fluorobenzamido)phenyl)-3-(4-fluorobenzoyl)thiourea species (1) has been synthesized and characterized by GC-MS, elemental analyses and 1 H NMR and FTIR spectroscopy techniques. The crystal structure of the novel compound -having a benzamide moiety attached to a thiourea nucleus -has been determined by X-ray diffraction. The species crystallize in the triclinic space group P-1, Z = 4, with 2 molecules per asymmetric unit. Additionally there is one ethylacetate solvent molecule per asymmetric unit. The carbonyl and thiourea groups are almost planar and the conformation adopted by the C@S and the C@O double bonds is mutually antiperiplanar. Density functional theory methods have been applied to determine the conformational space around the central -C(O)NHC(S)NH-moiety. The vibrational properties have been studied by FTIR and FT-Raman spectroscopy along with quantum chemical calculations at the B3LYP/6-311+G Ã level of approximation.