3-Nitro-2-phenylchroman

In the title compound, C15H13NO3, the dihedral angle between the two aromatic rings is 79.25 (16)°.

In the title compound, C 15 H 13 NO 3 , the dihedral angle between the two aromatic rings is 79.25 (16) .

Related literature
For pharmaceutical and synthetic applications of compounds with a benzopyran framework, see: Horton et al. (2003); Murugesh et al. (1996);Engler et al. (1990

Comment
Compounds containing a benzopyran framework have anti-tumour, anti-bacterial and anti-inflammatory activities (Horton et al., 2003). Additionally, they are also useful intermediates in the synthesis of complex natural products (Engler et al.,1990;Murugesh et al., 1996). The title compound, a member of this class of compounds, was synthesised and characterised by X-ray crystallography.
As shown in Fig. 1, the crystal structure determination indicates that the dihedral angle between the two aromatic rings is 79.25 (16)°.

Refinement
The H atoms were positioned geometrically (C-H = 0.95-0.98 Å) and refined as riding with U iso (H) = 1.2U eq (C).  The molecular structure of (I). Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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 R-factors(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.