Discovery of New Ferroelectrics: H2dbco2·Cl3·CuCl3(H2O)2·H2O (dbco = 1,4-Diaza-bicyclo2.2.2octane)

Compound H(2)dbco(2) x Cl(3) x CuCl(3)(H(2)O)(2) x H(2)O undergoes a sharp dielectric anomaly and a paraelectric-to-ferroelectric phase transition at approximately -23 degrees C with a spontaneous polarization of 1.04 microC cm(-2), being the first molecular metal coordination compound ferroelectrics with a large dielectric response involving a 2 orders of magnitude enhancement and distinct Curie phase transition point. This work has proved an effective way for exploration of new ferroelectrics based on a five-coordinated divalent metal through the combination of crystal engineering and Landau phase transition theory.