The asymmetric unit of the title compound, [K(C3H7O3)]n or K[H2gl]n, common name potassium glycerolate, contains half the K+ cation and half of the glycerolate anion. The other half of the anion is generated through a mirror plane passing through the K atom, and a C, an H and an O atom of the glycerolate ligand. The K+ ion is coordinated by the O atoms of the OH groups, leading to a six-membered chelate ring that adopts a very distorted boat conformation. The negatively charged O atom of the glycerolate anion, [H2gl−], is found in the flagpole position and forms an ionic bond with the K+ ion. The O atoms of the hydroxo groups are coordinated to two K+ ions, whereas the negatively charged O atom is bonded to one K+ ion. The K+ ion is coordinated by three other symmetry-related monodentate H2gl− ligands, so that each H2gl− ligand is bonded to two K+ ions, and the potassium has a seven-coordinate environment. The H2gl− ligands are connected via a strong O—H⋯O hydrogen bond and, together with the K⋯O interconnections, form polymeric sheets which propagate in the directions of the a and b axes
