3-Amino-1-(thiophen-2-yl)-9,10-dihydrophenanthrene-2,4-dicarbonitrile

In the title compound, C20H13N3S, the partially saturated ring adopts a twisted half-boat conformation with the methylene C atom closest to the aminobenzene ring lying 0.690 (6) Å out of the plane defined by the five remaining atoms. The dihydrophenanthrene residue has a folded conformation [dihedral angle between the outer benzene rings = 26.27 (18)°]. The thiophen-2-yl ring forms a dihedral angle of 63.76 (19)° with the benzene ring to which it is attached. In the crystal, inversion dimers linked by pairs of N—H⋯N hydrogen bonds generate R 2 2(12) loops. The dimers are linked into layers in the bc plane by weak C—H⋯π interactions. The thiophen-2-yl ring is disordered over two essentially coplanar but opposite orientations in a 0.918 (4):0.082 (4) ratio.

In the title compound, C 20 H 13 N 3 S, the partially saturated ring adopts a twisted half-boat conformation with the methylene C atom closest to the aminobenzene ring lying 0.690 (6) Å out of the plane defined by the five remaining atoms. The dihydrophenanthrene residue has a folded conformation [dihedral angle between the outer benzene rings = 26.27 (18) ]. The thiophen-2-yl ring forms a dihedral angle of 63.76 (19) with the benzene ring to which it is attached. In the crystal, inversion dimers linked by pairs of N-HÁ Á ÁN hydrogen bonds generate R 2 2 (12) loops. The dimers are linked into layers in the bc plane by weak C-HÁ Á Á interactions. The thiophen-2-yl ring is disordered over two essentially coplanar but opposite orientations in a 0.918 (4):0.082 (4) ratio. Experimental Crystal data C 20 H 13 N 3 S M r = 327.39 Monoclinic, P2 1 =c a = 9.7882 (10) Å b = 7.1199 (7) Table 1 Hydrogen-bond geometry (Å , ).

3-Amino
These stack along the a axis with no specific interactions between them.

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H = 0.95 to 0.99 Å, U iso (H) = 1.2U eq (C)] and were included in the refinement in the riding model approximation.
The amino H-atoms were located in a difference Fourier map, and were refined with a distance restraint of N-H = 0.88±0.01 Å; U iso were refined.
The thienyl ring is disordered over two positions in a 0.918 (4): 0.082 (4) ratio. The S-C distances were restrained to 1.71±0.01 Å, the formal C-C single-bond distances to 1.42±0.01 Å and the formal C═C double-bond distances to 1.42±0.01 Å. Additionally, the 1,3-related distances were restrained to within 0.01 Å of each other. Because pairs of atoms are close to each other, the U aniso of the C18′ atom were equated to those of the S1 atom (as well as the C19′/C20, C20′/C19′ and C18′/S1 pairs). The anisotropic displacement parameters were tightly restrained to be nearly isotropic.