Crystal structure of propane-1,3-diaminium squarate dihydrate

Abstract

Propane-1,3-diaminium squarate dihydrate, C3H12N22+·C4O42−·2H2O, results from the proton-transfer reaction of propane-1,3-diamine with squaric acid and subsequent crystallization from aqueous medium. The title compound crystallizes in the tetragonal crystal system (space group P4bm) with Z = 2. The squarate dianion belongs to the point group D4h and contains a crystallographic fourfold axis. The propane-1,3-diaminium dication exhibits a C2v-symmetric all-anti conformation and resides on a special position with mm2 site symmetry. The orientation of the propane-1,3-diaminium ions makes the crystal structure polar in the c-axis direction. The solid-state supramolecular structure features a triperiodic network of strong hydrogen bonds of the N—H...O and O—H...O types.

Keywords

• propane-1,3-diamine
• squaric acid
• proton-transfer compound
• hydrogen bonding
• polar structure
• crystal structure