Guanidinium Hydrogen Squarate

Abstract

The unit cell contains two crystallographically independent formula units, CH6N3+.C4HO4−, that are connected via a three-dimensional network of hydrogen bonds. Two crystallographically independent anion–cation chains are formed and arranged in two crystallographically independent layers and stacked along the b axis. The guanidine molecule accepts a proton from the squaric acid. Anions and cations are nearly planar. In the anions, the C—O and especially the C—C bond lengths differ significantly and the C—C—C angles deviate significantly from 90°.