2-(2-Iodophenyl)-1,2,3,4-tetrahydroisoquinoline-1-carbonitrile

In the title compound, C16H13IN2, the two benzene rings make a dihedral angle of 67.26 (5)°. The six-membered heterocycle of the tetrahydroisoquinoline unit adopts a half-chair conformation. In the crystal, adjacent molecules are linked by pairs of weak intermolecular C—H⋯N hydrogen bonds, forming inversion dimers. An intramolecular C—H⋯I close contact is also observed.

In the title compound, C 16 H 13 IN 2 , the two benzene rings make a dihedral angle of 67.26 (5) . The six-membered heterocycle of the tetrahydroisoquinoline unit adopts a half-chair conformation. In the crystal, adjacent molecules are linked by pairs of weak intermolecular C-HÁ Á ÁN hydrogen bonds, forming inversion dimers. An intramolecular C-HÁ Á ÁI close contact is also observed.

Comment
The tetrahydroisoquinoline derivatives have recently attracted great attention due to their neurotoxicity (Abe et al., 2005;Storch et al., 2002), antitumor activities (Lane et al., 2006;Wright et al., 1990), antimicrobial activity (Kamal et al., 2011;Liu et al., 2009), and so on. With the interests in the synthesis of tetrahydroisoquinoline derivatives with biological activity, we report here the synthesis and crystal structure of the title compound.
As shown in Fig. 1, the molecule of the title compound is built up from one 1-cyan-tetrahydroisoquinoline fragment connected to one 2-iodobenzene ring through the C-N bonds. Benzene C1-C6 and C11-C16 rings are inclined with respect to one another with a dihedral angle of 67.26 (5)°. The conformation of the six-membered ring of tetrahydroisoquinoline fragment is analyzed with respect to the plane formed by C1/C6/C7/C9 and the corresponding deviations of the atoms C8 and N1 are 0.459 (5) and 0.332 (3) Å, respectively. The C-N bonds within the tetrahydroisoquinoline fragment belong to single bond, the inter-ring C-N bond show some π-bond character, while the C-N bond of the cyano is of triple bond character.
In the crystal structure, two adjacent molecules are linked by a weak intermolecular C-H···N hydrogen bond into a dimer. These dimers are further connected by C-I···π interaction into a one-dimension chain along the b axis (Fig. 2). I1 aims at the π-cloud of the neighboring benzene ring C1-C6 (Cg), The I···Cg distance is 3.821 (2) Å with C···Cg of 5.622 (5) Å and C-I···Cg angle of 141.73°. An intramolecular C-H···I hydrogen bond is also observed (Table 1), which further consolidates the crystal packing.

Experimental
The title compound was synthesized according to the literature procedure (Ishii et al., 1985), and the single crystals were obtained from a solution of ethyl acetate by slow evaporation at room temperature.

Refinement
H atoms were treated as riding, with C-H = 0.93-0.98 Å, and with U iso (H) = 1.2U eq (C). The highest residual electron density peak is located 1.31 Å from atom C4.