2,6-Diisopropylanilinium Bromobismuthates.

A systematic approach to obtain bromobismuthates with various bismuth/halide ratios stabilised by 2,6-diisopropylanilinium cations [ArNH3] (Ar = 2,6-diisopropylphenyl) is presented. New bromobismuthate compounds [(ArNH3)(BiBr4)]∞ (1), [(ArNH3)3(Bi2Br9)]∞ (2), [(ArNH3)3(BiBr6)] (3) and [(ArNH3)4(BiBr6)(Br)] (4) with Bi/Br ratios of 1:4, 1:4.5, 1:6 and 1:7 have been isolated and structurally characterised. [Bi2Br9]∞ is a new structural motif in halobismuthate chemistry. In all the compounds, extensive hydrogen bonding is observed between the bromobismuthate moiety and the 2,6-diiosopropylanilinium cation, thus stabilising the inorganic–organic hybrid structures. Preliminary optical spectroscopic studies indicate that the optical band gap can be tuned by controlling the bismuth/halide ratio, which results in different dimensionalities in the halobismuthate structure. The compounds exhibit thermal stability up to 250 °C. [ABSTRACT FROM AUTHOR]