Date Published: August 01, 2012
Publisher: International Union of Crystallography
Author(s): Timothy J. McNeese, Robert D. Pike.
The title compound, 2C8H20N+·C2O42−·2H2O, synthesized by neutralizing H2C2O4·2H2O with (C2H5)4NOH in a 1:2 molar ratio, is a deliquescent solid. The oxalate ion is nonplanar, with a dihedral angle between carboxylate groups of 64.37 (2)°. O—H⋯O hydrogen bonds of moderate strength link the O atoms of the water molecules and the oxalate ions into rings parallel to the c axis. The rings exhibit the graph-set motif R44(12). In addition, there are weak C—H⋯O interactions in the crystal structure.
For related compounds containing planar and nonplanar oxalate ions, see: Beagley & Small (1964 ▶); Robertson (1965 ▶); Jeffrey & Parry (1954 ▶). For general syntheses of tetraalkylammonium salts and their uses, see: Barthel & Kunz (1988 ▶); Heck (1982 ▶); Markowitz (1957 ▶); McNeese et al. (1984 ▶); Starks (1971 ▶). For uses of [(C2H5)4N)2(C2O4)]·2H2O, see: Darensbourg et al. (1992 ▶); Demadis & Coucouvanis (1995 ▶); Diop et al. (1997 ▶); Engels et al. (1983 ▶). For classification of the graph-set motifs, see: Etter et al. (1990 ▶). For classification of the hydrogen bonds, see: Gilli & Gilli (2009 ▶). Oxalate was confirmed by the blue ring resorcinol test (Chernoff, 1920 ▶).