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

Hydrothermal reaction of ( L )- N -(2-cyano-benzyl)-( S )-proline with NaN 3 and Zn(ClO 4 ) 2 as a Lewis acid catalyst and H 2 O as a solvent gave {[Zn(TBPR)⊂0.25(HClO 4 )](0.25HClO 4 )} 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 ( P r = 1.8 μC/cm 2 ) and a lower closing mouth route.