Regulating the crystal and electronic structures and optical properties of hybrid bromoplumbates with alkylated N, S- or P-containing aromatic cations

Abstract

The optical properties including optical absorption and photoluminescence (PL) properties of hybrid materials are always required to be regulated to cater for different requirements. Herein, the crystal and electronic structures of hybrid haloplumbates were adjusted to regulate the optical properties by employing two series of well-designed structure directing agents (SDAs). Alkylated benzothiazole (btz)- and triphenylphosphine (PPh₃)-derivative SDAs direct the formation of six new hybrid bromoplumbates, namely (Mebtz)PbBr₃ (1, Me = methyl), (Etbtz)PbBr₃ (2, Et = ethyl), (Prbtz)Pb₃Br₈ (3, Pr = n-propyl), (MePPh₃)PbBr₃ (4), (EtPPh₃)PbBr₃ (5) and (PrPPh₃)PbBr₃ (6). Their bromoplumbate anions all show 1D chain-like structures formed by PbBr₆ octahedra but with different connection modes. The six hybrid materials possess obvious blue or red shifted band gaps compared with inorganic PbBr₂ due to their different structural features. Their PL emission colors realize rational regulation ranging from bluish green to orange.