Preparation and characterization of [H3N(CH2)6NH3]PbI4 and similar compounds with a layered perovskite structure

The preparation, crystal structure and optical absorption spectra of [H3N(CH2)6NH3]PbX4 (X = I, Br, Cl) and similar compounds based on Sn are described. The compounds [H3N(CH2)6NH3]PbX4 consist of ordered perovskite sheets of the corresponding-corner sharing PbX6 octahedra, which alternate with the H3N(CH2)6NH3 sheets. The excitonic peaks in the optical absorption spectra of these compounds occur at shorter wavelengths than those of the corresponding compounds with the formula [C6H5CH2CH2NH3]2MX4.