The electronic delocalization between chromophores in the solid is an important parameter to optimize when designing organic materials for optoelectronic applications. The [2.2]paracyclophane framework allows for the synthesis of well-defined, nonfluxional molecules that bring together two chromophores into close proximity. From the photophysical properties of these molecules we can examine how the chromophore conjugation length, their relative orientation, and the regiochemistry of contact affects the electronic delocalization between the two subunits.

We have studied the size effect of the homologues of the R,ω-diphenylpolyenes series, with two, three and four double bonds, on the formation of nanotubes with γ-cyclodextrin. The data show that only the two longest polyenes facilitate the formation of tubular structures when mixed with the γ-cyclodextrin in the appropriate solvent, while the average length of these nanotubes increases with increasing size of the diphenylpolyenes. Using computer simulations, we have examined the processes by which nanotubes form, and from computer fits we have determined the various binding constants, some with extremely large values, involved in the formation of these supramolecular structures.