Chemical Rearrangement under Hydrothermal Conditions:  Formation of Polymeric Chains (CuX)₂(dpiz) and (CuX)₃(dpiz) (X = Cl, Br; dpiz = Dipyrido[1,2-a:2‘,3‘-d]imidazole) and Crystal Structures of [(CuCl)₂(C₁₀H₇N₃)] and [(CuBr)₃(C₁₀H₇N₃)]

Reactions of CuX2 (X = Cl, Br) and 2,2‘-dipyridylamine (dpa) in superheated water (170 °C) led to a chemical rearrangement of dpa to dpiz (dpiz = dipyrido[1,2-a:2‘,3‘-d]imidazole = C10H7N3) and new Cu(I)-based coordination polymers (CuX)2(dpiz) and (CuX)3(dpiz). The crystal structures of [(CuCl)2(C10H7N3)] (I) and [(CuBr)3(C10H7N3)] (II) were reported. The two structures are built upon a common structural motif Cu2X4(C10H7N3).