Article

FT-IR, UV-vis, H-1 and C-13 NMR spectra and the equilibrium structure of organic dye molecule disperse red 1 acrylate: A combined experimental and theoretical analysis

Department of Physics, Afyon Kocatepe University, Afyonkarahisar, Turkey.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy (Impact Factor: 2.13). 09/2011; 83(1):561-9. DOI: 10.1016/j.saa.2011.09.003
Source: PubMed

ABSTRACT This study reports the characterization of disperse red 1 acrylate compound by spectral techniques and quantum chemical calculations. The spectroscopic properties were analyzed by FT-IR, UV-vis, (1)H NMR and (13)C NMR techniques. FT-IR spectrum in solid state was recorded in the region 4000-400 cm(-1). The UV-vis absorption spectrum of the compound that dissolved in methanol was recorded in the range of 200-800 nm. The (1)H and (13)C NMR spectra were recorded in CDCl(3) solution. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. A satisfactory consistency between the experimental and theoretical spectra was obtained and it shows that the hybrid DFT method is very useful in predicting accurate vibrational structure, especially for high-frequency region. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties were performed by timedependent DFT (TD-DFT) and CIS(D) approach. To investigate non linear optical properties, the electric dipole moment μ, polarizability α, anisotropy of polarizability Δα and molecular first hyperpolarizability β were computed. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the compound can be a good candidate of nonlinear optical materials.

0 Followers
 · 
275 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The band gaps, geometries, electronic structures, polarizabilities, hyperpolarizabilities, dipole moments, UV–visible, IR, 1H and 13C NMR of poly (3,4-ethylenedioxythiophene) (PEDOT) and its fluorine derivatives—Cn and 6 and 6 phenyl Cn butyric acid methyl esters (PCnBMs) bulk heterojunction (BHJ) solar cells are investigated by using density functional theory (DFT) and time-dependant density functional theory (TD-DFT) calculations. We aim to optimize the performance of these solar cells by altering the frontier orbital energy gaps of polymers and fullerenes. This was done by functionalizing the polymers backbones with electron withdrawing fluorines step-by step, and by adding phenyl butyric acid methyl ester to the buckminster C60 and C70 fullerenes. The theoretical data were compared with the available experimental data. Based on the strategy of reducing the bandgaps, the trifluoro derivative of PEDOT–buckminster C70 fullerene blend (out of 24 blends) was found to be the best candidate for power conversion efficiency (PCE). The addition of fluorine atoms to the polymer backbone is effective in lowering both HOMOs and LUMOs. Conformational analysis confirms that the coplanar propertyof thiophene polymers are not destroyed by the incorporation of fluorine atoms. While strong localization of HOMOs occurs on the PEDOT donor subunits, strong delocaliztion of LUMOs occurs on the bridges between the subunits, proving the flow of the electron density along the polymer backbone. The polarizability term βxxx and dipole moment μx increase with increasing the power conversion efficiency. The absorption band that corresponds to the maximum coefficient of the PEDOT in vacuum is marginally shifted under the effect of incorporating fluorines. Vibrational analysis shows that functionalizing PEDOT leads to a more conjugated polymer backbone and enhances the charge transfer to an acceptor. The power conversion efficiency of the solar cell increases with increasing the chemical shifts of the constituent C, H, and O atoms.
    Nano Energy 07/2012; 1(4):608–623. DOI:10.1016/j.nanoen.2012.04.002 · 10.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The synthesis and characterization of a novel compound (S)-N-benzyl-1-phenyl-5-(pyridin-2-yl)-pent-4-yn-2-amine (abbreviated as BPPPYA) was presented in this study. The spectroscopic properties of the compound were investigated by FT-IR, NMR and UV spectroscopy experimentally and theoretically. The molecular geometry and vibrational frequencies of the BPPPYA in the ground state were calculated by using density functional theory (DFT) B3LYP method invoking 6-311++G(d,p) basis set. The geometry of the BPPPYA was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The results of the energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) and CIS approach complement with the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The theoretical NMR chemical shifts ((1)H and (13)C) complement with experimentally measured ones. The dipole moment, linear polarizability and first hyperpolarizability values were also computed. The linear polarizabilities and first hyper polarizabilities of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The calculated vibrational wavenumbers, absorption wavelengths and chemical shifts showed the best agreement with the experimental results.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2012; 97:435-48. DOI:10.1016/j.saa.2012.06.041 · 2.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study presents the structural and spectroscopic characterization of 3,5-dibromoanthranilic acid with help of experimental techniques (FT-IR, FT-Raman, UV, NMR) and quantum chemical calculations. The vibrational spectra of title compound were recorded in solid state with FT-IR and FT-Raman in the range of 4000-400 and 4000-50cm(-1), respectively. The vibrational frequencies were also computed using B3LYP method of DFT with 6-311++G(d,p) basis set. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The (1)H, (13)C and DEPT NMR spectra were recorded in DMSO solution and calculated by gauge-invariant atomic orbitals (GIAO) method. The UV absorption spectra of the compound were recorded in the range of 200-400nm in ethanol, water and DMSO solutions. Solvent effects were calculated using time-dependent density functional theory and CIS method. The ground state geometrical structure of compound was predicted by B3LYP method and compared with the crystallographic structure of similar compounds. All calculations were made for monomeric and dimeric structure of compound. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken atomic charges of neutral and anionic form of the molecule were computed and compared with anthranilic acid.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2012; 96:644-56. DOI:10.1016/j.saa.2012.06.042 · 2.13 Impact Factor