2,4,6-Triphenylaniline

Individual molecules of the title compound, C24H19N, do not participate in hydrogen-bonding interactions due to the steric bulk of the phenyl rings ortho to the amine. The dihedral angles between the central ring and the pendant rings are 68.26 (10), 55.28 (10) and 30.61 (11)°.

Individual molecules of the title compound, C 24 H 19 N, do not participate in hydrogen-bonding interactions due to the steric bulk of the phenyl rings ortho to the amine. The dihedral angles between the central ring and the pendant rings are 68.26 (10), 55.28 (10) and 30.61 (11) .

Comment
The reactions of equimolar amounts of pyrazole-3,5-dicarboxylic acid (HPzDCA) and primary amines have yielded ammonium carboxylate salts that adopt layered architectures (Ugono et al., 2009;Beatty et al., 2002a,b). The level of structural fidelity for these organic salts allows, from a crystal engineering point of view, for the tuning of material properties by changing the identity of the organic group for the amines employed in the reaction. The reaction of pyrazole-3,5-dicarboxylic acid and 2,4,6-triphenylaniline (TPA) does not produce appreciable amounts of the desired ammonium carboxylate salt.
However, large colorless single crystals of the aniline were obtained and structurally characterized.
The title compound packs in the monoclinic space group P 2 1 /c, with one molecule in the asymmetric unit. TPA does not self aggregate via intermolecular hydrogen bonds in the solid state. This lack of significant intermolecular hydrogen bonds appears to be due to the bulky ortho phenyl groups. These groups ensure that the distance requirements for hydrogen bond interactions are not satisfied, as potential participating hydrogen bonding donors and acceptors can not approach each other. This is not uncommon, as other amines, namely 2,6-bis(Benzofuran-2-yl)phenylamine (Lonkin et al., 2004) and (R,R)-2,6-bis(1-Phenylethyl)4-methylaniline (Cherian et al., 2005) among others, exhibit this characteristic for identical reasons.

Experimental
Into a 20 ml scintillation vial was placed 65 mg (37 mmol s) of pyrazole-3,5-dicarboxylic acid, 120 mg (37 mmol s) of 2,4,6-triphenylaniline (Basu et al., 2003;Paul & Clark, 2003) and 5 ml of a 3:2 ethanol:water mixture. The mixture was warmed gently until the solution became clear and then filtered. The filtrate was placed in another scintillation vial, and colorless single crystals of the title compound were obtained in 48 h.

Refinement
All non hydrogen atoms were refined anisotropically. Phenyl hydrogen atoms were placed in calculated positions and treated with a riding model C-H= 0.95 Å, U iso (H aryl )= 1.2U eq (C) for aromatic carbons. Amine hydrogen atoms were also placed in calulated positions and treated with a riding model N-H= 0.88 Å, U iso (H amine )= 1.2U eq (N). Fig. 1. Thermal ellipsoid plot of 2,4,6-triphenylaniline at 50% probability.