A protonated salt constructed by tetrafluoroterephthalic acid and 5, 6-dimethyl benzimidazole: Design, synthesis, proton transfer and luminescent property

A steady self-assembled protonated salt, constructed by Tetrafluoroterephthalic acid (Tera) and 5, 6-dimethyl benzimidazole (DBZ), was designed and prepared in methanol/water solution. The structure and properties were characterized by experimental tests and analyzed by theoretical calculations on molecular level. Excellent symmetry of Tera, proton transfer bridged by water molecule, intermolecular hydrogen bonding play important roles in the self-assemble process. Proton migration analysis confirms the keying action of H2O molecules on co-crystallization. AIM analyses indicate hydrogen bonds are dominant to stabilize crystal packing. In addition, vibrational analysis and luminescent property of the protonated salt were also explored in details.