1,1′-(Ethane-1,2-diyl)bis(3-phenylthiourea)

The complete molecule of the title compound, C16H18N4S2, is generated by crystallographic inversion symmetry. The dihedral angle between the phenyl ring and the thiourea group is 52.9 (4)°. The crystal structure displays intermolecular N—H⋯S hydrogen bonding, which generates sheets in the ab plane.

The complete molecule of the title compound, C 16 H 18 N 4 S 2 , is generated by crystallographic inversion symmetry. The dihedral angle between the phenyl ring and the thiourea group is 52.9 (4) . The crystal structure displays intermolecular N-HÁ Á ÁS hydrogen bonding, which generates sheets in the ab plane.

Comment
Thiourea and urea functionalized ligands play key roles in a wide range of catalytic reactions. Here we report the crystal structure of such a compound (Lee et al., 1985) (Fig. 1). We recently reported a similar thiourea structure, where the molecules were bent (Pansuriya et al., 2011a). Bisthiourea and urea derivatives with alkane bridges can adopt two general shapes, bent (Pansuriya et al., 2011a) or straight alkyl chains (Pansuriya et al., 2011b;Koevoets et al., 2005). The spacer length between the two terminal thiourea or urea groups does not appear to influence the shape the bridging atoms take.
The reaction mixture was stirred for 2 hrs at room temperature and quenched with water (200 ml). This reaction mixture was then maintained overnight at room temperature. Then the reaction mixture was acidified with conc. HCl up to pH 2.6.
The solvents were evaporated under reduced pressure, the residue was suspended in hot water for 30 min. The resulting precipitate was filtered by vacuum. The product was washed with ice cold water and dried. The yield was 2.90 g (35%).

Refinement
Hydrogen atoms were first located in the difference map then positioned geometrically and allowed to ride on their respective parent atoms with C-H distances of 0.95 Å (C ar H), 0.99 Å (CH 2 ) and N-H distances of 0.88 Å. U iso (H) values were set to 1.2 U eq of the attached atom.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 40% probability level. The 1,1'-(ethane-1,2-diyl)bis(3-phenylthiourea) has inversion symmetry, so that unlabelled atoms are related by (1 -x, -y, 1 -z.  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 Rfactors(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.