Dynamics of Chiral Cations in Two-Dimensional CuX4and PbX4Perovskites (X = Cl and Br)

Masaki Takahashi, Norihisa Hoshino, Kohei Sambe, Takashi Takeda, Tomoyuki Akutagawa

    Research output: Contribution to journalArticlepeer-review

    13 Citations (Scopus)


    Chiral organic ammonium cations ((R)-2-methylphenethylammonium (R-MPhA) and (R)-3,7-dimethyloctylammonium (R-DMOA)) cations were combined with [MX4]2- anions (M = Cu and Pb, X = Cl and Br) to form two-dimensional (2D) perovskites: (R-MPhA)2CuCl4 (1a), (R-MPhA)2CuBr4 (1b), (R-DMOA)2CuCl4 (2a), (R-DMOA)2CuBr4 (2b), (R-DMOA)2PbCl4 (2c), and (R-DMOA)2PbBr4 (2d). The point shearing of the MX4 octahedron formed 2D perovskite layers, which were sandwiched by the bilayer molecular assembly of chiral organic ammonium cations. We found that the flexible and polar organic R-MPhA and R-DMOA cations in the 2D perovskites played an important role in the phase transition behavior and dielectric responses. Salts 2a-2d showed similar solid-solid (S1-S2) phase transitions, for which the temperatures decreased in the order of CuCl4 (2a) > PbCl4 (2c) > CuBr4 (2b) > PbBr4 (2d). The occupation volume of one R-DMOA per MX4 octahedron determined the dynamic crystalline space for the motional freedom of chiral ammonium in the 2D perovskite layer. Although thermally activated dielectric fluctuations were observed in salts 2a, 2b, and 2c, only an order-disorder-type dielectric phase transition was observed in salt 2d. Interband optical transitions were observed in the CuCl4 and CuBr4 2D perovskites, whereas sharp exciton absorptions were observed in the 2D PbCl4 and PbBr4 layers in perovskite salts 2c and 2d.

    Original languageEnglish
    Pages (from-to)11606-11615
    Number of pages10
    JournalInorganic chemistry
    Issue number16
    Publication statusPublished - 2020 Aug 17

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Inorganic Chemistry


    Dive into the research topics of 'Dynamics of Chiral Cations in Two-Dimensional CuX4and PbX4Perovskites (X = Cl and Br)'. Together they form a unique fingerprint.

    Cite this