Surface alignment of the N-octadecylazatriquinacenium cation as determined by sum frequency generation on the surface of H₂O and D₂O

The dimerization of two triquinacene hemispheres to give dodecahedrane is the holy grail of cycloaddition chemistry. Despite the substantial effort which has been invested in achieving this reaction over the years, no cycloaddition product has been reported. The reason for this failure is that the required endo-endo reactive configuration, involving six double bonds in an S₆ symmetrical relationship, is difficult to achieve. In this preliminary report, the self-organization of a triquinacene-based amphiphile at the air-water interface is studied by the surface-sensitive vibrational sum frequency generation technique. The results indicate that the triquinacene bowl is directed into the aqueous subphase, which suggests dimerization of triquinacene may be possible in an aqueous monolayer.