Precise design and preparation of two 3D organic-inorganic perovskite ferroelectrics (1,5-diazabicyclo[3.2.2]nonane)RbX 3 (X = Br, I).

Compared with the spherical molecule 1,4-diazoniabicyclo[2.2.2]-octane (2.2.2-dabco), 1,5-diazabicyclo[3.2.2]nonane (3.2.2-dabcn) bears a lower symmetry and larger size. As expected, reactions of 3.2.2-dabcn with rubidium halides gave two 3D molecular ferroelectrics [3.2.2-H 2 dabcn]RbX 3 (X = Br for 1; X = I for 2) with T c at 342 K (1) and 293 K (2).