Hydrothermal reaction of three-connecting ligands 1,3,5-tris(1-imidazolyl) benzene (tib) and MnSO4 or CoSO4·7H2O provides two new metal–organic frameworks, {[Mn(tib)2(H2O)4]SO4}n (1) and {[Co(tib)2(H2O)4]SO4}n (2). Single-crystal X-ray diffraction studies reveal that complexes 1 and 2 belong to the polar point group 3m, and have the same two-dimensional honeycomb networks with (6, 3) topology. The ferroelectric behavior investigation indicates that both compounds are typical ferroelectrics with an electric hysteresis loop showing a remnant polarization (Pr) of ca. 0.586 μC cm−2 and a coercive field (Ec) of 2000 V cm−1 for 1 and Pr of ca. 0.208 μC cm−2 and a coercive field (Ec) of 2600 V cm−1 for 2.
