1,2-Bis{2-[(4-methoxybenzylidene)amino]phenyl}disulfane

The asymmetric unit of the title compound, C28H24N2O2S2, contains one-half molecule, which is completed by twofold rotation symmetry with the twofold axis passing through the mid-point of the central S—S bond. The planes of the two benzene rings linked by the disulfide chain form a dihedral angle of 76.1 (1)°, while the planes of the two benzene rings in the benzylideneaniline fragment form a dihedral angle of 48.9 (1)°. The crystal packing exhibits no significantly short intermolecular contacts.

The asymmetric unit of the title compound, C 28 H 24 N 2 O 2 S 2 , contains one-half molecule, which is completed by twofold rotation symmetry with the twofold axis passing through the mid-point of the central S-S bond. The planes of the two benzene rings linked by the disulfide chain form a dihedral angle of 76.1 (1) , while the planes of the two benzene rings in the benzylideneaniline fragment form a dihedral angle of 48.9 (1) . The crystal packing exhibits no significantly short intermolecular contacts.  supplementary materials Acta Cryst. (2013). E69, o896 [doi:10.1107/S1600536813011598] 1,2-Bis{2-[(4-methoxybenzylidene)amino]phenyl}disulfane Wei Xin

Comment
As a contribution to structural study of diaminodiphenyl disulfides (İde et al., 1997;Wang et al., 2011;He et al., 2011), we present here the crystal structure of the title compound, (I).
In (I) (Fig. 1), the bond lengths and angles are normal and correspond to those observed in related compounds (İde et al., 1997;Ozbey et al.,1998;He et al., 2011). The molecule has crystallographic twofold rotation symmetry with the twofold axis passing through the midpoint of the central S-S bond. Two benzene rings connected through disulfide chain form a dihedral angle of 76.1 (1)°. Two benzene rings in two benzylideneaniline fragments form the dihedral angles of 48.9 (1)°. The crystal packing exhibits no significantly short intermolecular contacts.
Experimental 4-Methoxybenzaldehyde (2 mmol) in ethanol (10 ml) was added to a solution of 2,2′-diaminodiphenyl disulfide (1 mmol) in ethanol (20 ml). The solution was heated to 323 K for 4 h. The reaction mixture was cooled to room tempertature and the yellow crystalline product was obtained.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > 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.