Propanaminium p-toluenesulfonate

In the crystal structure of the title salt, C3H10N+·C7H7O3S−, N—H⋯O hydrogen bonds involving the ammonium groups of the cations and the sulfonate O atoms result in the formation of a three-dimensional network.

In the crystal structure of the title salt, C 3 H 10 N + ÁC 7 H 7 O 3 S À , N-HÁ Á ÁO hydrogen bonds involving the ammonium groups of the cations and the sulfonate O atoms result in the formation of a three-dimensional network.   Table 1 Hydrogen-bond geometry (Å , ).  (Helvenston et al., 2006;Collier et al., 2006;Koshima et al., 2001). As an extension of this research, the synthesis and crystal structure of the title compound, (C 3 H 10 N + )(C 7 H 7 O 3 S -) -, aiming at enriching the series of p-toluenesulfonates is presented herein.

Related literature
Ferroelectric compounds have a wide use in modern science. These compounds have displayed such technical applications as ferroelectric random access memories, ferroelectric field-effect transistors, piezoelectric sensors, nonlinear optical devices as a result of their excellent ferroelectric, piezoelectric, pyroelectric, and optical properties.
Numerous new ferroelectric metal-organic coordination compounds corresponding to the necessary requirements for ferroelectric properties have been found, yet other necessary conditions, such as a phase transition, a good electric hysteresis loop and electric domain, and a dielectric anomaly, are often missed in these compounds (Zhang et al., 2009). Therefore pure organic compounds have a tendency to make up for the drawbacks found in ferroelectric metal-organic coordination compounds. As part of our search for simple ferroelectric compounds, the title compound was investigated and its crystal structure is reported herein.
The asymmetric unit of the unit cell contains one anion and one cation that are shown in Fig. 1. Hydrogen bond interactions are listed in Table 1. The compound remains stable as a result of the existence of several hydrogen bond interactions formed in the crystal structure. These interactions tie the cations and anions together in a complex spatial geometry displayed in Fig2).

Experimental
(C 3 H 10 N + )(C 7 H 7 O 3 S -) was formed from a mixture of propylamine, C 3 H 9 N (118.22 mg, 2.00 mmol), and p-toluenesulfonic acid, C 7 H 7 SO 3 H (172 mg, 1.00 mmol), and distilled water (10 mL). The reaction mixture was stirred a few minutes at room temperature, giving a clear solution. After evaporation of the solvent for a few days, block-shaped colorless crystals suitable for X-ray diffraction were obtained in 86% yield, filtered and washed with distilled water.

Refinement
H atoms bound to carbon and nitrogen were placed at idealized positions [C-H = 0.93 to 0.97 Å and N-H = 0.89 Å] and allowed to ride on their parent atoms with U iso fixed at 1.2 U eq (C,N).   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.