Bis{2-[(Triphenylmethyl)amino]phenyl} diselenide acetonitrile monosolvate

The molecular structure of the title compound, C50H40N2Se2·C2H3N, shows a syn conformation of the benzene rings bound to the Se atoms, with an Se—Se bond length of 2.3529 (6) Å and a C—Se—Se—C torsion angle of 93.53 (14)°. The two Se-bonded aromatic ring planes make a dihedral angle of 18.42 (16)°. Intramolecular N—H⋯Se hydrogen bonds are noted. Intermolecular C—H⋯Se interactions give rise to supramolecular chains extended along [100]. One severely disordered acetonitrile solvent molecule per asymmetric unit was treated with SQUEEZE in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]; the crystal data take the presence of this molecule into account.

We thank the German Research Council (DFG) and the Federal Ministry of Education and Research (BMBF) for continued support of our work.
After the solvent was evaporated 100 ml water was added and the mixture was extracted with dichloromethane (3 x 80 ml). The combined organic layers were dried over Na 2 SO 4 . After filtration the solvent was removed und the crude product was obtained as a yellow powder. For purification, the raw product was stirred in acetonitrile (250 ml) for one hour at 80 °C. The hot suspension was filtered. The collected solid was washed with acetonitrile and dried under reduced poressure. Yield: 3.5 g (85%). Yellow crystals suitable for X-ray diffraction were obtained by diffusion of Et 2 O into a cold saturated MeCN solution. 3.47.

Refinement
Hydrogen atoms were clearly identified in difference syntheses, refined at idealized positions riding on the carbon atoms with isotropic displacement parameters U iso (H) = 1.2U(C eq ) and C-H 0.

Figure 1
Molecular structure of the title compound. Anisotropic displacement ellipsoids are drawn at the 50% probability level.

Bis{2-[(Triphenylmethyl)amino]phenyl} diselenide acetonitrile monosolvate
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.