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

Abstract

The structure of 4-methoxy-1-naphthol, C(11)H(10)O(2), (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 pi-pi 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 pi-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 pi-pi stacking interactions, and sheets are formed by O-H...pi and C-H...pi interactions.

Two isostructural halogen derivatives of 9-ethylcarbazole: crystal structure, Hirshfeld surface analysis, and structural comparison with other simple analogs

“…For example, as it is shown in our previous papers [19][20][21], the introduction of the simple substituents (OH, NH 2 , OCH 3 , and particularly halogen substituents) to the molecule of the simplest polycyclic AH, i.e., naphthalene, leads to a change in the packing of aromatic skeletons of this hydrocarbon, from the typical HB arrangement, to the more advantageous pstacking with considerable overlapping of p-electron orbitals between adjacent molecules in the stack. Such situations took place in the case of 1-naphthol (refcode in Cambridge Structural Database (CSD) [22]: NAPHOL01 [23]) and naphthalene derivatives carrying different substituents at positions 4 or 5, i.e., 4-chloro-, 4-methoxy-and 5-amino-1-naphthol (CSD refcodes: BOTSOT [19], CUF-KOE [20] and FUHTAE01 [21], respectively), 1,4-dihydroxy-, 1,4-dichloro-and 1,4-dibromonaphthalene (CSD refcodes: NPHHQU10 [24], DCLNAQ [25] and DBRNAQ01 [26], respectively) and 1,5-dihydroxynaphthalene (VOGRUE [27]). Moreover, it is interesting to note that generally the values of area overlap (AO) estimated for them, using the geometric model proposed by Janzen et al [12], depended on the substituent type.…”

Spatial packing of diols and esters with imidazoquinazoline ring—quantum-mechanical modeling

“…A herringbone arrangement means packing in which the planes of neighboring molecules are inclined with respect to each other, usually by an angle of 70-90°. In both types of structures, characteristic interactions appear [14][15][16][17][18][19][20].…”