Orbital Analysis of Natural Bonds, Calculations of the Functional Theory of Density Time-Dependent and Absorption Spectral of a Series of Rhodanine Derivatives (original) (raw)
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Synthesis and spectroscopical study of rhodanine derivative using DFT approaches
The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of (E)-5-benzylidene-2-thioxothiazolidine-4-one (E5BTTO) have been investigated experimentally and theoretically based on Density Functional Theory (DFT) approach. The FT-Raman and FT-IR spectra of E5BTTO were recorded in solid phase. Theoretical calculations were performed at the DFT level using the Gaussian 03 program. The experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumber by their Total Energy Distribution (TED). The results of the calculation were applied to simulate infrared and raman spectra of the title compound which showed good agreement with the observed spectra. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. Stability arising from hyperconjugative interactions leading to its NLO activity and charge delocalization were analyzed using Natural Bond Orbital (NBO) analysis.
Theoretical study of methylidene rhodanine tautomerism
2010 INTERNATIONAL KHARKOV SYMPOSIUM ON PHYSICS AND ENGINEERING OF MICROWAVES, MILLIMETER AND SUBMILLIMETER WAVES, 2010
The density functional theory (DFT) was used to calculate the relative stability of rhodanine dimers and the energy of intermolecular interaction in them. Analysis of the electron density showed hydrogen bonding in the dimers. The energies of individual hydrogen bonds were determined for the symmetrical dimers. The polarizable continuum model was used to calculate the solvation (hydration) energies of the structures studied. The effect of dimerization on the position of infrared absorption bands was demonstrated.
A Molecular Orbital Treatment of the Electronic Structure and Spectra of Tautomeric Rhodanines
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The electronic structures of some aryl nitrones have been investigated using the MNDO-MO method. Equilibrium geometries, and charge density distributions have been computed. Various electronic differences between nitrones and the corresponding imines have been analyzed and discussed. The electronic absorption spectra of the studied nitrones have been analyzed and interpreted using the results of MO comput~tion. Charge density distribution, dipole moments and the extent of delocalization of the MO's were used to interpret the observed solvent effects. Comparison between the spectra of aryl nitrones and that of the corresponding imines led to conclusions regarding the: structural differences between the two classes of compounds.
Optical and Electronic Properties of Molecular Systems Derived from Rhodanine
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Push-Pull functional compounds consisting of dicyanorhodanine derivatives have attracted a lot of interest because their optical, electronic, and charge transport properties make them useful as building blocks for organic photovoltaic implementations. The analysis of the frontier molecular orbitals shows that the vertical transitions of electronic absorption are characterized as intramolecular charge transfer; furthermore, we show that the analyzed compounds exhibit bathochromic displacements when comparing the presence (or absence) of solvent as an interacting medium. In comparison with materials defined by their energy of reorganization of electrons (holes) as electron (hole) transporters, we find a transport hierarchy whereby the molecule (Z)-2-((1,1-Dicyanomethylene)-5-(4-dimethylamino)benzylidene)-1,3-thiazol-4 is better at 1
Chemistry of Heterocyclic Compounds, 2002
Ab initio (HF and MP2 level) and semiempirical (AM1, PM3, MNDO) calculations on the relative stabilities and structures of the potential tautomeric forms of rhodanine, isorhodanine, thiazolidine-2,4-dione, and thiorhodanine are reported. Ab initio calculations predict that the thiooxo, oxothio, dioxo, and dithio tautomers are the most stable. These results correspond to the known experimental data. Infrared spectra of the investigated compounds were recorded for the region 4000-150 cm-1, and the characteristic bands were compared with ab initio calculated frequencies at the HF/3-21G(*)* level.
The Influence of 5-Substituents on the Supramolecular Structures of Rhodanine Derivatives
Crystal Growth & Design, 2007
In this paper, we describe how the crystal structures of 5-benzylidenerhodanines are influenced by substituents on the phenyl ring and those of 5-cycloalkylidenerhodanines by the size of the cycloalkane ring. Although the R 2/2 (8) (CONH) 2 ring of rhodanine is generally retained in these structures, the dimers so created are associated in a wide variety of ways, often through weak interactions such as C-H‚‚‚S/O, C-H‚‚‚π, or Br‚‚‚S/O bonds. In some cases, solvent molecules present in the lattice also play a significant role in the self-organization of the crystals.
Potentiometric, thermodynamics and theoretical calculations of some rhodanine derivatives
Journal of Molecular Liquids, 2016
A series of 5-(4′-alkylphenylazo)-3-phenylamino-2-thioxothiazolidin-4-one (HL n) have been prepared and characterized by elemental analysis, 1 H NMR and IR spectra. X-ray diffraction pattern of ligand (HL 2) was studied. The geometrical structures of these ligands are carried out by HF method with 3-21G basis set. Proton-ligand dissociation constant of ligands (HL n) and their metal-ligand stability constants of Mn 2+ , Co 2+ , Ni 2+ and Cu 2+ have been determined potentiometrically in 0.1 M KCl and 30% (v/v) DMSO-water mixture at 298, 308 and 318 K. The stability constants of the formed complexes increase with the order: Mn 2+ b Co 2+ b Ni 2+ b Cu 2+. The effect of temperature was studied and the corresponding thermodynamic parameters (ΔG, ΔH and ΔS) were derived and discussed. The dissociation process is non-spontaneous, endothermic and entropically unfavorable. The formation of the metal complexes has been found to be spontaneous, endothermic and entropically favorable. Proton-ligand dissociation constant (pK H) of the ligands increases according to the following order p-(OCH 3 N H N NO 2) as expected from Hammett's constant (σ R).
1. Introduction The chemistry of heterocyclic compounds is the most important in the discovery of new drugs. pyrimidine is one of the most important heterocycles with pharmacological activities because it is an essential constituent of all cells and thus of all living matter [i]. Hence, they have received the consideration of researchers due to its manifold implication viz, antibacterial, antifungal, anticancer, antitumor, antiallergic, analgesic, anti inflammatory, and antineuplastic [ii-iv]. Some pyrimidine derivatives are also reported as good corrosion inhibitors because of the presence of hetero atoms and delocalized π-electrons [v-vii].Generally, nitrogen containing heterocyclic compounds such as pyridine and pyrimidine derivatives favourable for NLO conditions due to the presence of lone pair electrons. Recently pyrimidine derivatives reported as a good non-linear material [viii-x]. In spite of the application of pyrimidine derivatives, a venture has been undertaken for the synthesis of 5-(3,5-difluoro-4-hydroxyphenyl)-5,6,7,8-tetrahydro-7-thioxopyrimido[4,5-d]-pyrimidine-2,4(1H,3H)-dione compound. The aim of present work is to study the structural activity of the DTTP molecule by using density functional theory. To best of our knowledge, there is no computational studies has been reported for the DTTP compound. Hence, the present investigation deals with using DFT method of calculations along with experimental measurements of FT-IR, FT-Raman spectra was undertaken to study the vibrational spectra of studied molecule completely and to identify the various normal modes with greater wave number accuracy. In this present study, optimized molecular structural parameters, HOMO-LUMO analysis and NLO property (first hyperpolarizability) are carried out to elucidate the information regarding energy gap and charge transfer within the molecule. In addition, molecular electrostatic potential (MEP), mulliken charge distribution and thermodynamic parameters of the DTTP compound are studied by using density functional theory.
Journal of Molecular Structure, 2016
The rhodanines of the title (Xp-Rhod, X ¼ F, Cl, Br, I) were synthesized and characterized in solid state and in solution. The crystal structures of the four compounds show different supramolecular organizations. In the F-, Cl-and Br-derivatives, a R 2 2 ð8Þ (CSNH) 2 ring forms via NeH/S hydrogen bonds between two neighbouring molecules to give dimers. The I-derivative is also dimeric, but exhibits R 2 2 ð8Þ (CONH) 2 rings. The two type of dimers are associated in a variety of structures through hydrogen bonding, pstacking, CeH/p interactions and halogen bonding. These interactions were analysed from a crystallographic point of view and their relative relevance was explored using DFT calculations. The effect produced on all these interactions by the incorporation of DMSO molecules to the lattice was analysed by comparing the crystal structures of Xp-Rhod compounds and those of corresponding Xp-Rhod$DMSO solvates.