Syntheses and characterization of aryl-substituted pyrogallol[4]arenes and resorcin[4]arenes

Abstract

Seven aryl-substituted pyrogallol[4]arenes and six aryl-substituted resorcin[4]arenes were synthesized through the acid catalyzed reaction of either pyrogallol or resorcinol with a specific alkoxybenzaldehyde. Single crystal X-ray data was obtained for all thirteen compounds. In order to determine the effect of the different pendent –R groups, four properties were investigated: π–π distance, inward tilt, twist angle, and the angle between the planes containing the pendent –R groups. Positioning of the –R groups, the carbon atom chain length of the –R groups, the number of upper-rim hydroxyl groups (resorcin[4]arene vs. pyrogallol[4]arene), and the number of substituted phenyl groups all influenced these four properties. The trends that develop are investigated and discussed.