Crystal structure and dielectric property of supramolecular macrocyclic [(NDPA)·(18-crown-6)]2+·(DMA)+·3ClO4− assemblies

One novel organic–inorganic hybrid supramolecular assemblies [(NDPA)·(18-crown-6)]2+·(DMA)+·3ClO4− (1), has been successfully constructed through the prominent strategies of crystal engineering (NDPA = N,N-dimethyl-1,4-phenylenediamine, DMA = dimethylamine), and characterized by IR, powder XRD and single crystal X-ray diffraction. In the structure, the supramolecular organic cations and inorganic ClO4− anions are arranged alternately and linked by NO⋯H hydrogen bonds. It is worthy to note that the ClO4− are linked to form one-dimensional inorganic chain through strong NH⋯O hydrogen bonds along b-axis. There is no distinct dielectric anomaly in the temperature-dependent and frequency-dependent dielectric constant curves, suggesting that no phase transition exists within the measured temperature range (120–420 K). The relative displacement of cations and anions, the turned polarization of molecular electric moment and macrocyclic molecule rotator are the main factors to determine the trend of dielectric constant.

Macrocycle-based supramolecular compounds were synthesized based on the rotator–stator assemblies. Ammonium cations insert into the crown ether to form H-bonding rotator–stator assembly.Figure optionsDownload as PowerPoint slide