Abstract: | The title compound (C6H7NO3S) exists as a zwitterion (4‐ammoniobenzenesulfonate), +H3NC6H4SO3?, and these units are linked into a three‐dimensional framework by two distinct two‐centre N—H?O hydrogen bonds H?O 1.84 and 1.87 Å; N?O 2.767 (2) and 2.746 (2) Å; N—H?O 166 and 172°] and a planar three‐centre N—H?(O)2 hydrogen bond H?O 2.03 and 2.37 Å; N?O 2.816 (2) and 2.877 (2) Å; N—H?O 162 and 111°; O?H?O 86°]. |