Research Article: 4-{4-[(E)-(2-Hy­droxy­phen­yl)imino­methyl]phen­oxy}benzene-1,2-di­carbo­nitrile

Date Published: March 01, 2012

Publisher: International Union of Crystallography

Author(s): Hülya Tuncer, Ahmet Orhan Görgülü, Tuncer Hökelek.


The asymmetric unit of the title compound, C21H13N3O2, contains two independent mol­ecules with a similar structure. In one mol­ecule, the central benzene ring is oriented with respect to the terminal benzene rings at 27.23 (7) and 67.96 (7)°; in the other mol­ecule, the corresponding dihedral angles are 12.42 (7) and 64.55 (7)°. In both molecules, there is a short O—H⋯N interaction involving the OH group and the adjacent N atom. In the crystal, there are O—H⋯N hydrogen bonds, and C—H⋯O and N—H⋯O interactions linking the molecules to form a three-dimensional network. π–π stacking between the pyridine and benzene rings and between the benzene rings [centroid–centroid distances = 3.989 (2), 3.705 (2) and 3.607 (2) Å] may further stabilize the structure. A weak C—H⋯π inter­action is present in the crystal.

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For the use of phthalonitriles for preparing symmetrically and unsymmetrically substituted phthalocyanine complexes, see: Leznoff & Lever (1996 ▶). For the widespread applications of phthalocyanines in photodynamic therapy, see: Kartal et al. (2006 ▶); Tüfekçi et al. (2009 ▶). For the fundamental optical and electronic properties of phthalocyanines, see: McKeown (1998 ▶). For related structures, see: Tuncer et al. (2012 ▶); Tüfekçi et al. (2009 ▶); Yazıcı et al. (2009 ▶); Kartal et al. (2006 ▶). For bond-length data, see: Allen et al. (1987 ▶).