4-Ethylphenol

The title compound, C8H10O, crystallizes with three molecules in the asymmetric unit. O—H⋯O hydrogen bonds form cooperative chains connecting the molecules along [100]. On the unitary graph level, this pattern is assigned a DDD descriptor. The ternary descriptor is C 3 3(6).

The title compound, C 8 H 10 O, crystallizes with three molecules in the asymmetric unit. O-HÁ Á ÁO hydrogen bonds form cooperative chains connecting the molecules along [100]. On the unitary graph level, this pattern is assigned a DDD descriptor. The ternary descriptor is C 3 3 (6).

Comment
In a program focused on the influence of bonding to pentavalent central atoms on the geometry of aromatic alcohols, the crystal structure of para-ethylphenol was determined.
There are three molecules in the asymmetric unit which do not show non-crystallographic symmetry ( Fig. 1 and Fig.   2). The hydrogen atoms on the hydroxy groups reside in the planes of the respective aromatic moiety whereas the alkyl chains are oriented approximately perpendicular to them. The least-squares planes defined by the aromatic moieties and the atoms of the hydroxy group and their respective aromatic carrier atom enclose angles roughly between 1° and 16°. The least-squares planes defined by the aromatic moieties and the C atoms of the alkyl chain and their respective aromatic carrier atom intersect at angles roughly between 77° and 80°.
The hyxdroxy groups furnish the formation of cooperative chains of hydrogen bonds along [1 0 0] (Fig. 3). In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), this pattern can be ascribed a DDD descriptor on the unitary level. The ternary descriptor of these chains is C 3 3 (6). The molecules are packed in a pseudo-trigonal mode with the hydrophilic part of the molecules residing in the center of these entities (Fig. 4).
The molecular packing of the title compound is shown in Figure 5.

Experimental
The compound was obtained commercially (Aldrich) and used for diffraction studies as received.

Refinement
Due to the absence of a strong anomalous scatterer in the molecule the absolute structure parameter, which is 0.7948 with an estimated standard deviation of 1.2829 for the unmerged data set, is meaningless. Thus, Friedel opposites (1849 pairs) have been merged and the absolute configuration has been arbitrarily chosen. The absolute structure parameter has been removed from the cif.
Carbon-bound H-atoms were placed in calculated positions (C-H 0.95 Å for aromatic C atoms, C-H 0.99 Å for methylene groups, C-H 0.98 Å for methyl groups and O-H 0.84 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C) for aromatic C atoms and methylene groups, U(H) set to 1.5U eq (C) for methyl groups and U(H) set to 1.5U eq (O) for the hydroxy groups.