Hirshfeld Surface Analysis of Substituted Phenols

The effect of para -substituents on the crystal packing of phenols has been investigated, for systems bearing nonpolar groups ( tert -butyl and benzyl, compounds 1 and 2, respectively) and for methylene linked bis-phenol bearing polar nitro groups (compound 3 ). Remarkable for 1 and 2, the asymmetric unit has six molecules, which form infinite helical hydrogen bonded arrays in the extended structures, whereas compound 3 bearing nitro groups coplanar with the phenol rings forms almost columnar arrays. Hirshfeld surface analysis is used to show that despite packing in a nearly identical manner, 1 and 2 are distinctly different in their interactions, and these structures are compared to compound 3, where the solid-state interactions are dominated by the nitro moieties.