Tanklike Metal−Organic Framework Filled with Perchloric Acid and Its Dielectric−Ferroelectric Properties

Hydrothermal reaction of (L)-N-(2-cyano-benzyl)-(S)-proline with NaN3 and Zn(ClO4)2 as a Lewis acid catalyst and H2O as a solvent gave {[Zn(TBPR)⊂0.25(HClO4)](0.25HClO4)}n (1) (TBPR = (S)-N-2-tetrazoylbenzylproline), an unique homochiral one-dimensional cage- or tanklike metal−organic framework (MOF) in which the cage or tank is filled with free perchloric acid. Permittivity property measurements reveal that 1 exhibits a high dielectric loss, which suggests it could be a potentially useful material for dielectric heating (such as electrocaloric effect), while ferroelectric property measurements show a possible hysteresis loop with a large remnant polarization (Pr = 1.8 μC/cm2) and a lower closing mouth route.