[Bis(2-hydroxyethyl)amino]tris(hydroxymethyl)methane (Bis–Tris), an important complexing agent

The title compound, (HOCH2CH2)2NC(CH2OH)3 or C8H19NO5, is an important complexing agent. All hydroxyl-H atoms are involved in intermolecular hydrogen bonds (O—H⋯O distances are in the range 2.690–2.847 Å), which link the mol­ecules in the crystal into a three-dimensional infinite network. One of the hydroxy­methyl hydroxyl groups also participates in an intramolecular O—H⋯N hydrogen bond, closing a five-membered N—C—C—O—H pseudo-cycle [O⋯N 2.7804 (16) Å and O—H⋯N 118.6 (17)°].