Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-Aldrich This is illustrated using the methoxynaphthalenefunctionalized epoxycyclobutane 160, which is reacted with functionalized norbornenes 93,56, and 148 to produce polyalicyclic structures 161-163, respectively, as examples of space-separated bichromophoric systems.
Source: wiktionary