Synthesis, structure and ferroelectric–dielectric properties of an acentric 2D framework with imidazole-containing tripodal ligands

The 2D acentric metal–organic framework (MOF) of {[Fe(tib)2/3(H2O)4]SO4}n (1) (tib=1,3,5-tris(1-imidazolyl) benzene) was obtained from hydrothermal reaction of tib and FeSO4·7H2O in the presence of water and methanol (or ethanol). Investigation of its ferroelectric property shows that the compound is a typical ferroelectric and its electric hysteresis loop shows a remnant polarization (Pr) of ca. 0.27μC/cm2 and coercive field (Ec) of 2kV/cm. Dielectric constant studies show that complex 1 exhibits maximal dielectric constant around 4.62 in 18.5°C.