Adamantan-1-aminium p-toluenesulfonate

There are two unique cations and anions in the asymmetric unit of the title molecular salt, C10H15NH3 +·C7H7O3S−. In the crystal, all three hydrogen-bond donors of the protonated amine group make hydrogen-bond interactions with sulfonate O-atom acceptors, linking the cations and anions into chains parallel to the a axis. C—H⋯π interactions are also present.

There are two unique cations and anions in the asymmetric unit of the title molecular salt, C 10 H 15 NH 3 + ÁC 7 H 7 O 3 S À . In the crystal, all three hydrogen-bond donors of the protonated amine group make hydrogen-bond interactions with sulfonate O-atom acceptors, linking the cations and anions into chains parallel to the a axis. C-HÁ Á Á interactions are also present.

Experimental
Crystal data

Comment
Owing to its highly symmetrical and stable structure, adamantane and its derivatives have generated much interest in the past and continue to be actively studied as evidenced by the large number of compounds containing amantadine that have been synthesized (Tukada & Mochizuki, 2003;Zhao et al., 2003;He & Wen, 2006 In the molecule of the title compound, the bond lengths and angles are within their normal ranges. There are two pairs of adamantane-1-ammonium cation and toluene-4-sulfonic acid anion in one asymmetric unit (Fig. 1). The dihedral angle between the benzene ring A (C22-C27) and benzene ring B (C29-C34) is A/B = 20.83 °. The two molecules are both stabilized by N-H···O hydrogen bonding, among which, N1-H1C···O4 and N2-H2C···O1 are intramolecular hydrogen bonds. All three hydrogen donors of the protonated amine group give direct hydrogen-bonding associations, with three of the sulfonate O-atom acceptors from three independent toluene-4-sulfonic acid anions. The hydrogen bonds are summarized in Tab. 1. Fig. 2 shows a view down the c axis. The N-H···O hydrogen bonds between the discrete adamantane-1-ammoniumcations and toluene-4-sulfonic acid anions result in a noteworthy one-dimensional ribbon-like structure parallel to (1 0 0) (Fig. 2). This ribbon motif is the dominant hydrogen-bonding motif (Hulme et al., 2006). In addition, strong π-ring C7 -H7A···Cg9 iii , C4 -H4B···Cg10 iv , C19 -H19B··· Cg10 v interactions exist which contribute to crystal stability [Cg9 and Cg10 is the center of gravity of ring A and B, Symmetry code: (iii) -x + 1, -y + 1, -z + 1; (iv) x -1, y, z; (v) x, y -1, z.]
Colorless single crystals of the title compound suitable for X-ray analysis were obtained by slow evaporation of the solvents over a period of a week.
The dielectric constant of the compound as a function of temperature indicates that the permittivity is basically temperature-independent (ε = C/(T-T 0 )), suggesting that this compound is not ferroelectric or there may be no distinct phase transition occurring within the measured temperature range between 93 K and 362 K (m.p. 99 o C).

Refinement
The positional parameters of all C-bound H atoms were calculated geometrically and allowed to ride, with U iso (H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for all other H atoms. All ammonium H atoms were found in a difference Fourier map and refined with restraints for the N-H distances of 0.87 (2) Å. Fig. 1. The molecular structure of the title compound, with the atomic numbering scheme and displacement ellipsoids drawn at the 30% probability level.  as those based on F, and R-factors based on ALL data will be even larger.