Solvent mediated centric/non-centric polymorph pairs of an indole derivative: subtle variation of C-HO hydrogen bonds and C-Hπ interactions

Abstract

Centric (P2₁/n) and non-centric (P2₁) polymorphic pairs of biologically active 1-(4-fluorophenyl)-6,6-dimethyl-2-phenyl-1,5,6,7-tetrahydro-4H-indol-4-one crystallized from different solvents have been elucidated via single crystal and powder X-ray diffraction studies, morphological observations and calorimetric measurements. C-H...O hydrogen bonding and weak intermolecular C-H...π interactions generate distinct packing features in the two forms.