Triflate's bigger brother: The unprecedented tribrate anion, [Br3CSO3]−

Abstract

AbstractThe synthesis of the unprecedented [Br3CSO3]− anion starts with the bromination of phenylmethanesulfonate, C6H5OSO2CH3, with KOBr leading to C6H5OSO2CBr3. The formation of the [CBr3] moiety has been proved, also by an X‐ray structure determination of the compound (triclinic, P‐1, a=685.9(2), b=698.1(2), c=1190.2(3) pm, α=93.99(1)°, β=97.42(1)°, γ=94.45(1)°). The ester C6H5OSO2CBr3 can be split under basic conditions. The resulting acid provides access to the yet unknown tribromomethanesulfates (“tribrates”). K[Br3CSO3] ⋅ H2O, the first tribrate known so far has been characterized comprehensively, including an X‐ray structure determination (monoclinic, C2/c, a=2267.1(2), b=1282.25(8), c=2618.2(2) pm, β=111.266(2)°), vibrational spectroscopy and theoretical calculations. Moreover, the thermal analysis shows that, after loss of the crystal water, the tribrate decomposes between 530 and 630 K.