Molecular structure investigation and spectroscopic studies on 2,3-difluorophenylboronic acid: A combined experimental and theoretical analysis
No Thumbnail Available
Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This work presents the characterization of 2,3-difluorophenylboronic acid (abbreviated as 2,3-DFPBA, C6H3B(OH)2F 2) by quantum chemical calculations and spectral techniques. The spectroscopic properties were investigated by FT-IR, FT-Raman UV-Vis, 1H and 13C nuclear magnetic resonance (NMR) techniques. The FT-IR spectrum (4000-400 cm-1) and the FT-Raman spectrum (3500-10 cm-1) in the solid phase were recorded for 2,3-DFPBA. The 1H and 13C NMR spectra were recorded in DMSO solution. The UV-Vis absorption spectra of the 2,3-DFPBA that dissolved in water and ethanol were recorded in the range of 200-400 nm. There are four possible conformers for this molecule. The computational results diagnose the most stable conformer of the 2,3-DFPBA as the trans-cis form. The structural and spectroscopic data of the molecule were obtained for all four conformers from DFT (B3LYP) with 6-311++G (d,p) basis set calculations. The theoretical wavenumbers were scaled and compared with experimental FT-IR and FT-Raman spectra. 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, interpreted in terms of fundamental modes. We obtained good consistency between experimental and theoretical spectra. 13C and 1H NMR chemical shifts of the molecule were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, absorption wavelengths, HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Finally the calculation results were analyzed to simulate infrared, Raman, NMR and UV spectra of the 2,3-DFPBA which show good agreement with observed spectra. © 2012 Elsevier B.V. All rights reserved.
Description
Keywords
Anisotropy , Boronic Acids , Dimethyl Sulfoxide , Electrons , Hydrocarbons, Fluorinated , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Conformation , Nonlinear Dynamics , Optical Phenomena , Quantum Theory , Solutions , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Static Electricity , Thermodynamics , Vibration , Electronic properties , Ethanol , Fluorine , Nuclear magnetic resonance , Nuclear magnetic resonance spectroscopy , Quantum chemistry , Quantum theory , Raman scattering , Spectroscopic analysis , Ultraviolet spectroscopy , 2,3 difluorophenylboronic acid , 2,3-difluorophenylboronic acid , boronic acid derivative , dimethyl sulfoxide , fluorinated hydrocarbon , Absorption wavelengths , Atomic orbital , Basis sets , Computational results , DFT , FT-IR spectrum , FT-Raman , FT-Raman spectrum , FTIR and FT-Raman spectra , Fundamental modes , HOMO-LUMO , Infrared and Raman spectra , LUMO energy , NMR chemical shifts , NMR spectrum , Nuclear magnetic resonance techniques , Quantum chemical calculations , Scaled Quantum Mechanics , Solid-phase , Spectral techniques , Spectroscopic data , Spectroscopic property , Spectroscopic studies , Stable conformers , Theoretical spectra , Time-dependent DFT , Total energy distributions , UV , UV spectrum , UV-VIS absorption spectra , Vibrational modes , Wave numbers , anisotropy , article , chemical structure , chemistry , conformation , electron , infrared spectroscopy , light related phenomena , nonlinear system , nuclear magnetic resonance spectroscopy , quantum theory , Raman spectrometry , solution and solubility , static electricity , thermodynamics , ultraviolet spectrophotometry , vibration , Molecules