Crystal structure of sodium squarate trihydrate, Na2C4O4 · 3H2O

The crystal structure of the trihydrate sodium salt of the squaric acid has been determined by X-ray analysis. The squaric anions, linked in ribbons by hydrogen bridges, extend through the crystal in directions parallel to the ab plane diagonals, and are arranged in stacks by the b translation. Adjacent ribbons along the c direction are coplanar, but interleaved with sodium cations octahedrally surrounded by oxygen atoms.