An experimental and theoretical study of molecular structure and vibrational spectra of 3-and 4-pyridineboronic acid molecules by density functional theory calculations

WOS: 000257573000029PubMed ID: 17933583The experimental and theoretical vibrational spectra of 3- and 4-pyridineboronic acids (abbreviated as p3 and p4) were studied. The Fourier transform Raman and Fourier transform infrared spectra of p3 and p4 molecules were recorded in the solid phase. The structural and spectroscopic analysis of the p3 and p4 acids were made by using density functional harmonic calculations. Both p3 and p4 only one form was most stable using B3LYP level with the 6-31G(d), 6-31G(d,p), 6-311G(d), 6-311G(d,p) and 6-311++G(d,p) basis sets. Selected experimental bands were assigned based on the scaled theoretical wavenumbers. Finally, geometric parameters, infrared and Raman bands and intensities were compared with experimental data of the molecules. (C) 2007 Elsevier B.V. All rights reserved

Experimental and Theoretical Vibrational Spectroscopic Study of Zinc (II) Halide Complexes of 4-Acetylpyridine

WOS: 000418818000042In the present work, we present a detailed experimental and theoretical study of the zinc (II) halide complexes of 4-acetylpyridine (abbreviated as 4-Ap) (Zn (L)(2) X-2, [where L: C7OH7N; X: Cl, Br and I]). The infrared and Raman spectra of the zinc (II) halide complexes of 4-Ap have been recorded between 400-4000 cm(-1) and 5-3500 cm(-1) regions, respectively. The analysis of the FT-IR and FT-Raman spectra indicates that some structure-spectra correlations. For a given series of isomorphous complexes, the sum of the differences between the values of the vibrational modes of uncoordinated 4-Ap was found to increase in order of second ionization potentials of metal. The molecular geometry and vibrational frequencies of the zinc (II) halide complexes of 4-Ap in the ground state have been calculated by using the Density Functional Method (B3LYP) with LANL2DZ and SDD as basis sets. A complete assignment of the fundamentals was proposed based on the total energy distribution (TED) calculation

FT-IR and Raman Spectroscopy and Computation of 5-Methylfurfural

WOS: 0004405908000245-Methylfurfural (5MF) was studied by vibrational (IR and Raman) spectroscopy and computational methods (DFT/B3LYP&MP2). FT-IR and FT-Raman spectra in KBr (at room temperature) were collected. The Gaussian 09 and Spartan 08 programs were used for conformational analysis and calculations of molecular structure, torsional barrier, and vibrational spectral data for the 5MF molecule. The obtained results were used in the analysis of experimental vibrational spectra of 5MF molecule

Comparing of the host-guest interaction in the Hofmann-1,10-diaminodecane and Hofmann-1,12-diaminododecane-type clathrates

WOS: 000275650800005M(1,12-diaminododecane)Ni(CN)4.G (M = Co, Ni or Cd; G = chlorobenzene; 1,2-; 1,3- or 1,4- dichlorobenzene) clathrates were prepared in powder form for the first time and their infrared spectra were reported and then compared with M(1,10-diaminodecane)Ni(CN)(4).1,5G (M = Co, Ni or Cd; G = chlorobenzene; 1,2-; 1,3- or 1,4-dichlorobenzene) clathrates. The spectral results suggest that the characteristic nu(CN) and delta(NiCN) frequencies are found to be similar to those known for the Hofmann type compounds, in that prepared compounds are similar in structure to this type compounds and their structures consist of polymeric layers [M-Ni(CN)(4)](a) with the 1,12-diaminododecane molecule bound to the metal atom (M). Also, the results suggest that the ligand molecule with 10 to 12 of chain length have no effect on vibrational bands of the guest molecules in the similar Hofmann-diam-type clathrates. The normal mode frequencies and corresponding vibrational assignments of chlorobenzene and 1,2-; 1,3- or 1,4-dichlorobenzene in the ground state were calculated by DFT/B3LYP level of theory using the 6-311G(d, p) basis set in Gauss-view. In addition, these theoretical results were compared to the experimental results for the vibrational modes of host molecules