Order-disorder antiferroelectric phase transition in a hybrid inorganic-organic framework with the perovskite architecture

[(CH3)(2)NH2]Zn(HCOO)(3), 1, adopts a structure that is analogous to that of a traditional perovskite, ABX(3), with A = [(CH3)(2)NH2], B = Zn, and X = HCOO. The hydrogen atoms of the dimethyl ammonium cation, which hydrogen bond to oxygen atoms of the formate framework, are disordered at room temperature. X-ray powder diffraction, dielectric constant, and specific heat data show that I undergoes an order-disorder phase transition on cooling below similar to 156 K. We present evidence that this is a classical paraelectric to antiferroelectric phase transition that is driven by ordering of the hydrogen atoms, This sort of electrical ordering associated with order-disorder phase transition is unprecedented in hybrid frameworks and opens up an exciting new direction in rational synthetic strategies to create extended hybrid networks for applications in ferroic-related fields.