A novel proton transfer supramolecular compound induced by N–H⋯O hydrogen bond through 18-crown-6: Syntheses, structures, and dielectric properties

• A novel organic–inorganic hybrid supramolecular compound was prepared and characterized.
• The compound presents a new one-dimensional supramolecular chain structure via N-H…O contacts through the cavity of 18-crown-6.
• A strong dielectric response suggested proton transfers between intermolecular N-H…O hydrogen bonds.

A novel organic–inorganic hybrid supramolecular compound, [(4-Nitroanilinium)(18-crown-6)][BF4](CH3CN), was prepared via H-bond dipole interactions between 4-nitroanilinium, 18-crown-6, and BF4−, in acetonitrile solution. N–H…O hydrogen bonds between neighboring 4-nitroanilinium cations and 18-crown-6 were observed. However, the formation of one-dimensional supramolecular chain structure via N–H…O that contacts through the cavity of 18-crown-6 was worth noting. A strong dielectric response was observed above 300 K at a low frequency of 500 Hz, thereby suggesting the proton transfer in the N–H…O bonds.

a) View of the self-assembly packing of 18-crown-6 and 4-nitroanilinium along the b-axis in complex 1, showing N–H…O hydrogen bond interactions in the one-dimensional chain structure through the cavity of 18-crown-6. Blue ring represents 18-crown-6. b) Dielectric constants of complex 1 measured along the b-axis at frequencies of 500 Hz to 1 MHz.Figure optionsDownload as PowerPoint slide