1-Carboxy-3-phenylpropan-2-aminium chloride

The title compound, C9H12NO2 +·Cl−, is the hydrochloride of an N-substituted glycine derivative. The non-H atoms of the alkyl part of the molecule lie nearly in a plane (r.m.s. deviation of all fitted non-H atoms = 0.0142 Å). In the crystal structure, O—H⋯Cl, N—H⋯Cl and C—H⋯O hydrogen bonds involving both O atoms as well as C—H⋯Cl contacts connect the components of the title compound into a three-dimensional network.


Related literature
For the crystal structure of a palladium coordination compound featuring the ethyl ester of N-benzylglycine as a ligand, see: Freiesleben et al. (1995). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990); Bernstein et al. (1995).
Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 1-Carboxy-3-phenylpropan-2-aminium chloride E. Hosten, T. Gerber and R. Betz Comment Amino acids play a major role in the metabolism of living creatures and are characterized by their omnipresence as well as their easy availability in both nature as well as industry. From a chemical viewpoint, their molecular set-up denotes them as potential chelate ligands whose denticity and charge can be influenced by simple variation of the pH value. Coordination compounds featuring amino acids in their ligand sphere might have interesting pharmaceutical properties, especially when keeping in mind that derivatization of the respective amino acids can be used for fine-tuning thermodynamic as well as kinetic characteristics of the compounds and the tailoring of secretion rates on grounds of hydrophilicity. In our continuous efforts in elucidating the rules guiding the formation of N,O-supported chelate ligands, we investigated the crystal structure of the title compound to enable comparative studies of metrical parameters in envisioned metal complexes. Information about the molecular and crystal structure of a palladium coordination compound featuring the ethyl ester of N-benzylglycine is apparent in the literature (Freiesleben et al., 1995).
Intracyclic C-C-C angles cover a range of 118.0 (5)-121.5 (6) ° with the smallest angle found on the substituted carbon atom and the biggest angle in ortho position to this atom. The non-hydrogen atoms of the alkyl part of the molecule are nearly in plane (r.m.s of all fitted non-hydrogen atoms = 0.0142 Å). The least-squares planes defined by these atoms on the one hand and the carbon atoms of the aromatic system on the other hand enclose an angle of 60.21 (21) ° (Fig. 1).
In the crystal structure, classical hydrogen bonds as well as C-H···O contacts and C-H···Cl contacts whose range falls by up to more than 0.2 Å below the sum of van-der-Waals radii of the respective atoms are observed. The classical hydrogen bonds are apparent between the nitrogen-and oxygen-bonded hydrogen atoms as donors and -exclusively -the chloride anion as acceptor While the C-H···O contacts are apparent between both hydrogen atoms of the amino acid's methylene group and the oxygen atom of the hydroxyl group, the C-H···Cl contacts stem from one of the aromatic system's hydrogen atoms in ortho position to the substituent. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for the classical hydrogen bonds is DDD on the unitary level while the C-H-supported contacts necessitate a DC 1 1 (4)C 1 1 (4) descriptor on the same level. The C-H···O contacts are present as antidromic chains. In total, the entities of the title compound are connected to a three-dimensional network. π-Stacking is not a prominent feature with the shortest intercentroid distance between two aromatic systems found at 5.029 (4) Å, the length of the a axis (Fig. 2).
The packing of the title compound in the crystal is shown in Figure 3.

Experimental
The compound was obtained commercially (Fluka). Crystals suitable for the X-ray diffraction study were obtained upon slow evaporation of an aqueous solution of the compound at ambient temperature.
supplementary materials sup-2 Refinement Carbon-bound H atoms were placed in calculated positions (C-H 0.95 Å for aromatic C atoms, C-H 0.99 Å for the methylene group) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C). The H atom of the hydroxyl group was allowed to rotate with a fixed angle around the C-O bond to best fit the experimental electron density (HFIX 147 in the SHELX program suite (Sheldrick, 2008)), with U(H) set to 1.5U eq (O). Both nitrogenbound H atoms were located on a difference Fourier map and refined freely. Fig. 1. The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level).    (6) 3.166 (5) 178 (6) N1-H72···Cl1 1.07 (6) 2.15 (6) 3.148 (5) 154 (5) C2-H2A···O1 iii 0.99 2.48 3.364 (7) 148.