Redetermination of 4-hydroxybenzaldehyde

This is a redetermination of the structure of the title compound, C7H6O2, which was first reported by Iwasaki [Acta Cryst. (1977 ▶), B33, 1646–1648]. The results are obtained with greater precision in the present study. Crystal packing is stabilized by intermolecular O—H⋯O interactions between the hydroxyl and aldehyde groups which link the molecules into chains in a zigzag pattern along the [110] plane of the unit cell.

This is a redetermination of the structure of the title compound, C 7 H 6 O 2 , which was first reported by Iwasaki [Acta Cryst. (1977), B33, 1646-1648]. The results are obtained with greater precision in the present study. Crystal packing is stabilized by intermolecular O-HÁ Á ÁO interactions between the hydroxyl and aldehyde groups which link the molecules into chains in a zigzag pattern along the [110] plane of the unit cell.
MTS thanks the Sambhram Institute of Technology for the use of their research facilities. RJB acknowledges the NSF-MRI program (grant No. CHE-0619278) for funds to purchase the X-ray diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LX2042).
used in the preparation of benzopyrans and have wide applications in the perfume, cosmetic and pharmaceutical industry (Dean, 1963;Bigi et al., 1999). They are also used in the preparation of chelating resins (Samal et al., 1999).
The crystal structures of p-hydroxybenzaldehyde (Iwasaki, 1977), 2-bromo-5-hydroxybenzaldehyde , a new polymorph of 2-bromo-5-hydroxybenzaldehyde (Silva et al., 2004), 3-hydroxybenzaldehyde (Paixão et al., 2000) and 2,4-dibromo-5-hydroxybenzaldehyde, (Matos Beja et al., 1997) have been reported. In view of the importance of the title compound in the pharmaceutical industry, this paper reports a redetermination of the crystal structure with greater precision and accuracy. Crystal packing is stabilized by intermolecular O-H···O interactions between the hydroxyl and aldlehyde groups which link the molecules into chains in a zigzag pattern along the [110] plane of the unit cell (Fig. 2).

Experimental
A sample of 4-hydroxybenzaldehyde was obtained from Sigma-Aldrich and was recrystallized from ethylacetate by slow evaporation to obtain good quality crystals (m.p.: 385-387 K).