Ionothermal synthesis, structure and optical properties of three new organic–inorganic hybrid imidazolium bromoplumbate complexes

By heating imidazolium bromide-based ionic liquids with Pb(NO3)2 under ionothermal conditions, we have successfully generated three imidazolium bromoplumbates, namely, [(PMI)PbBr3]n (1), [(AMI)PbBr3]n (2) and [(HMI)PbBr3]n (3) (PMI = 1-propyl-3-methylimidazolium, AMI = 1-allyl-3-methylimidazolium, HMI = 1-hexyl-3-methylimidazolium). Compounds 1–3 are isomorphic and exhibit unusual supramolecular organization wherein dialkylimidazolium cations arrange themselves in a cylindrical fashion giving rise to channel structures, which are further occupied by the 1D zigzag [PbBr3]n inorganic chains. The UV–vis diffuse reflectance spectra and luminescence measurements indicate that all compounds are potential semiconductor and photoluminescence materials.