(E)-1-[(Diphenylamino)methyl]-4-(4-fluorobenzylideneamino)-3-[1-(4-isobutylphenyl)ethyl]-1H-1,2,4-triazole-5(4H)-thione

The title 1,2,4-triazole compound, C34H34FN5S, exists in a trans configuration with respect to the acyclic C=N bond. An intramolecular C—H⋯S contact generates a six-membered ring, producing an S(6) ring motif. The essentially planar 1,2,4-triazole ring [maximum deviation 0.008 (1) Å] is inclined at 21.43 (5) and 83.03 (6)°, respectively, with respect to the flurophenyl unit and the isobutyl-substituted benzene ring. The diphenylamino unit is not planar, as indicated by the dihedral angle between two phenyl rings of 76.95 (6)°. The crystal structure is stabilized by C—H⋯π and π–π [centroid–centroid distance = 3.6169 (6) Å] interactions; molecules are stacked along the b axis.


Experimental
The title 1,2,4-triazole compound was obtained by the Mannich reaction of Schiff base (0.01 mol), formaldehyde (40 %, 1 ml) and N,N-diphenylamine (0.01 mol) in ethanol (10 ml) after stirring at room temperature for 20 h. The solid product obtained was collected by filtration, washed with ethanol and dried. Colourless single crystals were obtained from a 1:2 mixture of N,N-dimethylformamide and ethanol by slow evaporation.

Refinement
All hydrogen atoms were placed in their calculated positions, with C-H = 0.93 -0.97 Å, and refined using a riding model with U iso = 1.2 or 1.5 U eq (C). A rotating group model was used for the methyl groups. Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme. An intramolecular contact is shown as dashed line.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 > 2sigma(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.16117 (