Structural Diversity In Layered Hybrid Perovskites, A(2)Pbbr(4) Or Aa'Pbbr4, Templated By Small Disc-Shaped Amines

We present three new hybrid layered lead(II) bromide perovskites of generic composition A(2)PbBr(4) or AA'PbBr4 that exhibit three distinct structure types. [TzH](2)PbBr4 ([TzH(+)] = 1,2,4-triazolium) adopts a (001)-oriented layer structure and [AaH](2)PbBr4, ([AaH(+)] = acetamidinium) adopts a (110)-oriented type, whereas [ImH][TzH]PbBr4, ([ImH(+)] = imidazolium) adopts a rare (110)-oriented structure with enhanced corrugation (i.e., 3 x 3 type). The crystal structures of each are discussed in terms of the differing nature of the templating molecular species. Photoluminescent spectra for each are reported and the behaviors discussed in relation to the different structure of each composition.