PHENYL-PERFLUOROPHENYL STACKING INTERACTIONS - TOPOCHEMICAL[2+2] PHOTODIMERIZATION AND PHOTOPOLYMERIZATION OF OLEFINIC COMPOUNDS

The face-to-face stacking interaction between phenyl and perfluorophen yl groups is emerging as a common noncovalent interaction. To explore the generality of this supramolecular synthon, the solid-state packing structure and reactivity of several monoolefins and diolefins substit uted with phenyl and perfluorophenyl groups was investigated. Of the s even crystalline or cocrystalline materials investigated, six were fou nd to undergo a photochemically induced [2+2] reaction in the solid st ate. By determining the stereochemistry of the photoproduct and/or X-r ay structural analysis of the olefinic precursors, the stacked interac tion between phenyl and perfluorophenyl groups in the photoactive crys tals were revealed.