Interplay between Aryl···Perfluoroaryl and Hydrogen Bonding Interactions in Cocrystals of Pentafluorophenol with Molecules of Trigonal Symmetry

Abstract

Cocrystals of seven star-shaped triaryl compounds with pentafluorophenol (pfp) were prepared and structurally characterized by the single-crystal X-ray diffraction method. Cocrystallization of pfp with planar (or almost planar) compounds gave six 3:1 molecular complexes with well-defined layered structures. The layers are composed of alternating pfp 3 trimers, linked by hydrogen bonding, and triaryl molecules held together in planes by the weak C−H•••F interactions. Stacking interactions of the triaryl-substituted molecules with the perfluorinated rings of pfp are responsible for the overall crystal packing, but most likely also stabilize the trimers in the solid state, as the assembly of the pfp into trimers provide an optimal geometry for the π•••π interaction. The layers are flat for the cases of components with almost planar geometry and corrugated for those with more twisted geometry. In the case of nonplanar triphenyl isocyanurate, the pfp cocrystal does not contain pfp 3 trimers, the stoichiometry changes from 3:1 to 3:2 (3 refers to pfp), and the packing is mainly controlled by intermolecular O−H•••OC hydrogen bonding.

Phosphonated Ionomers of Intrinsic Microporosity with Partially Ordered Structure for High-Temperature Proton Exchange Membrane Fuel Cells

“…A molecular model of PIM-P also showed the H-bonded chain interactions, which led to the aggregation of phosphonic acid groups (Figure c). Phosphonic acid groups act as both donors and acceptors of H-bonds and form several types of hydrogen-bonded O–H···O aggregates including chains, dimers, and rings (Figure d). , These aggregates constituted a continuous network of H-bonds between molecular chains. Due to the presence of intermolecular H-bonds, the internal rotation of molecular segments was restricted, resulting in a partially ordered structure.…”

Self-assembly of secondary aryl amides in cocrystals with perfluoroaryl coformers: structural analysis and synthon preferences

“…[13][14][15][16] control crystal structure of supramolecular assemblies. 17 Continuing our interest in this subject we turned our attention to aryl secondary cis-amides having potential for both these types of interactions (the amide group is known to form hydrogen bonds, whereas the aryl unit can act as a π-donor).…”

Intermolecular Hydrogen Bonding Directed by Aryl–Perfluoroaryl π–π Stacking Interactions

“…The majority of the reported crystallographic studies have dealt with cocrystals of aromatic hydrocarbons and perfluoro­carbons. − Much less research has been done on cocrystals of compounds bearing functional groups. − Moreover, the competition or cooperation between hydrogen bonding and π–π stacking interactions in molecular self-assembly has been identified as a useful effect in crystal engineering. − For example, we have recently shown that cocrystallization of star-shaped triaryl compounds with pentafluorophenol induces the formation of hydrogen-bonded cyclic trimers due to aryl–perfluoroaryl stacking interactions …”

“…48−52 For example, we have recently shown that cocrystallization of starshaped triaryl compounds with pentafluorophenol induces the formation of hydrogen-bonded cyclic trimers due to aryl− perfluoroaryl stacking interactions. 53 This article is licensed under CC-BY 4 In this context, we were curious about whether π−π stacking interactions could help to control the supramolecular assembly via HBs. As the first example, we chose 8-ethynylquinoline (1, Scheme 1), which was expected to form dimers due to self- 12) motif (I, Scheme 2).…”