Synthesis, characterization, crystal structure and theoretical approach of (E)-2-[(3-carboxylphenylimino)methylene]phenoxyacetic acid

The title compound, (E)-2-[(3-carboxylphenylimino)methyl]phenoxyacetic acid (C16H13NO5), had been synthesized and characterized by FT-IR, UV–vis spectrum, fluorescence spectrum, elemental analysis, electrochemistry and single crystal X-ray diffraction techniques. Crystallographic analysis show that non-covalent CH⋯Cg and inter-molecular hydrogen bonding interactions assemble the 3D network structure of the title compound. Moreover, the vibrational frequencies of the title compound in the ground state had been calculated using the Hartree–Fock (HF) and density functional methods (B3LYP) with 6-31G* and 6-31+G(d) basis set, respectively. The results of the calculational optimized molecular structure, absorption spectra and fluorescence emission are exhibited and compared with the experimental results of X-ray diffraction, UV–vis spectrum and fluorescence spectrum, respectively. In addition, frontier molecular orbitals (FMOs), mulliken charges, wiberg bond index and molecular electrostatic potential (MEP) were executed by the RB3LYP/6-31+G(d) method.

► Aromatic carboxylic acid compound had been synthesized and characterized.
► Part of crystal structure of compound shown formation of centrosymmetric R22(8) dimer.
► Compound engendered strong fluorescence emission in purple region.
► Redox action of compound is very difficult.
► DFT calculation results are good agreed with experimental data.