10-(2-Pyridyloxy)phenanthren-9-ol

In the title compound, C19H13NO2, the pyridyl ring makes a dihedral angle of 87.04 (6)° with the plane of the phenanthrene ring system. In the crystal, molecules are linked through weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions.

In the title compound, C 19 H 13 NO 2 , the pyridyl ring makes a dihedral angle of 87.04 (6) with the plane of the phenanthrene ring system. In the crystal, molecules are linked through weak intermolecular C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions.   Table 1 Hydrogen-bond geometry (Å , ).
The phenanthrene plane is essentially planar, with a mean deviation of 0.011 (2) |%A from the least-squares plane defined by the fourteen constituent atoms. The dihedral angle formed by the phenanthrene plane and the pyridyl ring is 87.04 (6)°.
The crystal packing (Fig. 2) is stabilized by a weak intermolecular C-H···O hydrogen bond between the pyidyl H atom and the oxygen of the hydroxyl group, with a C3-H3···O2 i ( Table 1). The crystal packing (Fig. 2) is further stabilized by two intermolecular C-H···π interactions; the first one between the benzene H atom of the phenanthrene unit and the pyridyl ring, with a C10-H10···Cg1, the second one between the benzene H atom of the phenanthrene unit and the central benzene ring of a neighbouring molecule, with a C15-H15···Cg2 (Table 1; Cg1 and Cg2 are the centroids of the N1/C1-C5 pyridyl ring and the C6/C7/C12/C13/C18/C19 benzene ring, respectively).

Experimental
To a solution of 2-pyridyl magnesium bromide in dry THF at 273° under nitrogen atomsphere, solution of phenanthren-9,10-dione in dry THF was added dropwise. After the addition, the mixture was stirred at room temp under nitrogen atmosphere for 3 h. After the completion of reaction as evidenced by TLC, the reaction was quenched with saturated solution of ammonium chloride and the mixture was extracted into diethyl ether. The organic layer was concentrated at reduced pressure. The residue was purified by coloumn chromotography (hexane-ethyl acetate, 9:1 v/v) to afford the title compound as a pale yellow solid (yield 75%, m.p. 418° K). Single crystals suitable for X-ray diffraction was recrystallized from mixture of dichlromehane-hexane (8: 2 v/v) as solvent.

Refinement
All H atoms were positioned geometrically, with C-H = 0.93-0.98 Å and constrained to ride on their parent atoms, with U iso (H) = xU eq (C, N), where x = 1.5 for methyl H and x = 1.2 for all H atoms.