2-(Pyrimidin-2-yloxy)phenol

The pyrimidine and benzene rings in the title compound, C10H8N2O2, form a dihedral angle of 71.03 (7)°, with the roughly orthogonal benzene ring being folded towards one of the pyrimidine N atoms. In the crystal, pairs of O—H⋯N hydrogen bonds connect molecules related by twofold symmetry into dimeric aggregates. These associate into a supramolecular chain propagating along the b axis by way of C—H⋯π contacts. The chains are cross-linked by π–π interactions that occur between pyrimidine rings [ring centroid–centroid distances = 3.5393 (9) and 3.5697 (9) Å].

The pyrimidine and benzene rings in the title compound, C 10 H 8 N 2 O 2 , form a dihedral angle of 71.03 (7) , with the roughly orthogonal benzene ring being folded towards one of the pyrimidine N atoms. In the crystal, pairs of O-HÁ Á ÁN hydrogen bonds connect molecules related by twofold symmetry into dimeric aggregates. These associate into a supramolecular chain propagating along the b axis by way of C-HÁ Á Á contacts. The chains are cross-linked byinteractions that occur between pyrimidine rings [ring centroid-centroid distances = 3.5393 (9) and 3.5697 (9) Å ].

Related literature
For background to the fluorescence properties of compounds related to the title compound, see: Kawai et al. (2001); Abdullah (2005). For a related structure, see: Nasir et al. (2010).  Table 1 Hydrogen-bond geometry (Å , ).

Comment
Interest in the title compound relates to screening for useful fluorescence properties as seen in related compounds (Kawai et al. 2001;Abdullah, 2005). The molecule of (I), Fig. 1, is bent with the dihedral angle formed between the pyrimidine and benzene rings being 71.03 (7) °. The plane through the pyrimidine ring cuts through the orthogonal plane through the benzene ring, which is folded to be disposed towards the N1 atom. The overall conformation resembles that reported recently for 2-(3-methoxyphenoxy)pyrimidine (Nasir et al., 2010). The hydroxy group is directed away from the pyrimidine ring, an orientation that facilitates the formation of a O-H···N hydrogen bond with a molecule related by 2-fold symmetry, Table   1. The dimeric aggregates are linked via C-H···π interactions occurring between a pyrimidine-H and the benzene ring. The result of these interactions is the formation of a supramolecular chain along the b axis, Fig. 2 and Table 1. The chains thus formed are consolidated into the crystal structure by π-π interactions occurring between the pyrimidine rings that stack along the c axis [ring centroid(N1,N2,C1-C4)···ring centroid(N1,N2,C1-C4) i,ii = 3.5393 (9) and 3.5697 (9) Å, respectively, with inclination angles = 16 and 0 °, respectively, for i: 1 -x, y, 3/2 -z and ii: 3/2 + x, 3/2 + y, 1 + z]; Fig. 3.
The water was then evaporated and the resulting paste heated with 2-chloropyrimidine (2 g, 18 mmol) at 423-433 K for 5 h. The product was dissolved in water and the solution extracted with chloroform. The chloroform phase was dried over sodium sulfate; the evaporation of the solvent gave well shaped colourless blocks of (I).

Refinement
Carbon-bound H-atoms were placed in calculated positions (C-H 0.93 Å) and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2U equiv (C). The O-bound H-atom was located in a difference Fourier map, and was refined with a distance restraint of O-H 0.84±0.01 Å, and with U iso (H) set to 1.5U equiv (O). Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 50% probability level.   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 Rfactors(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.