N‐[Tris(hydroxymethyl)methyl]glycine (tricine)

The title compound, C₆H₁₃NO₅, adopts a zwitterionic form where the carboxylic acid H atom is transferred to the amino group. The methyl–glycine backbone is planar. The tris(hydroxy­methyl)­methyl group is rotated as a rigid group around the amino–methyl bond by 22 (1)° and the carboxylic acid plane is rotated by 19.76 (12)° from the plane of the main skeleton. Apart from their H atoms, the three hydroxy­methyl groups adopt a propeller‐like conformation around the amino–methyl bond, close to C₃ symmetry.