1D vs 2D crystal architecture of hybrid inorganic–organic structures with benzidine dication

A series of a dozen novel inorganic–organic hybrid salts of benzidine dication containing complex inorganic anions such as metal halides have been prepared and structurally characterized. Crystal structures obtained have either linear 1D or layered 2D architectures created by aromatic benzidine moieties aggregated in stacks or sheets. A small number of structures with polymerized inorganic layers of the perovskite-like type is associated with a relatively high 2D density of charge caused by close packing of organic cations with charge compensated by inorganic complex moieties. Also the dual nature of the benzidine cations helps in formation of stacks of molecules instead of layers. Another feature discussed is an inherent tendency to form twins caused by the way of packing of molecules in some of the presented crystals.