Synthesis, characterization, optical properties and theoretical calculations of 6-fluoro coumarin

•Calculated IR spectra may reproduce the experimental results.•Description of the largest vibrational contributed to the normal modes are given.•Calculated 1H NMR , 13NMR chemical shifts mainly agree with the experimental values.•TD-DFT can be used to give precise simulation of the absorption and emission spectra.•Theoretical B3LYP/6-311G(d,p)/B3LYP/Aug-CC-Pvdz calculations are valid for the structural-similar compounds.

6-Fluoro coumarin is synthesized and characterized by 1H NMR and 13C NMR. The optical properties of the title compound are investigated by UV–vis absorption and fluorescence emission spectra, the results show the title compound can absorb UV–vis light at 319, 269 and 215 nm, moreover it exhibits blue-purple fluorescence emission at 416 nm. Theoretical studies on molecular structure, infrared spectra (IR), nuclear magnetic resonance (1H NMR, 13C NMR) chemical shifts, UV–vis absorption and fluorescence emission of the synthesized compound have been worked out. Most chemical calculations were performed by density functional theory (DFT) method at the B3LYP/6-311G(d,p) level (NMR at B3LYP/Aug-CC-Pvdz level) using Gaussian 09 program. The compared results reveal that the scaled theoretical vibrational frequencies are in good accordance with the observed spectra; computational chemical shifts are consistent with the experimental values in most parts, except for some minor deviations; the UV–vis absorption calculated matches the experimental one very well, and the fluorescence emission spectrum is in good agreement with the experimental one when the solute–solvent hydrogen-bonding interaction is considered. These good coincidences prove that the computational methods selected can be used to predict these properties of other similar materials where it is difficult to arrive at experimental results.

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