4-Methoxy-1-naphthol: chains formed by O—H...O hydrogen bonds and π–π stacking interactions

The structure of 4-methoxy-1-naphthol, C₁₁H₁₀O₂, (I), contains an intermolecular O—H...O hydrogen bond which links the molecules into a simple C(2) chain running parallel to the shortest crystallographic b axis. This chain is reinforced by intermolecular π–π stacking interactions. Comparisons are drawn between the crystal structure of (I) and those of several of its simple analogues, including 1-naphthol and some monosubstituted derivatives, and that of its isomer 7-methoxy-2-naphthol. This comparison shows a close similarity in the packing of the molecules of its simple analogues that form π-stacks along the shortest crystallographic axes. A substantial spatial overlap is observed between adjacent molecules in such stacks. In this group of monosubstituted naphthols, the overlap depends mainly on the position of the substituents carried by the naphthalene moiety, and the extent of the overlap depends on the substituent type. By contrast with (I), in the crystal structure of the isomeric 7-methoxy-2-naphthol there are no O—H...O hydrogen bonds or π–π stacking interactions, and sheets are formed by O—H...π and C—H...π interactions.