Novel organic-inorganic hybrid compounds, CnN2PbBr4 (n=4,6,8 and 10) and C2N2PbBr4 . DMSO, were prepared by the self-organization of lead bromide and a variety of alkyldiammonium cations. The powder X-ray diffraction patterns of CnN2PbBr4 demonstrated that the compounds form layered perovskite structures and the interlayer spacing are dependent on the length of alkyl chain. The absorption and fluorescence spectra of CnN2PbBr4 and C2N2PbBr4 . DMSO crystalline powder showed an excitonic absorption peak at around 390 nm, which suggests that the formation of two-dimensional inorganic sheets and quantum confinement structure.