A new method is described enabling to get 3D – Metal-Organic Rotaxane Framework (MORF) crystals featuring cucurbiturils as rings and viologens as active pillars which, upon photoexcitation are reduced to colorfull viologen radicals…

A new method is described enabling to get 3D – Metal-Organic Rotaxane Framework (MORF) crystals featuring cucurbit[7]urils as rings and viologens as active pillars which, upon photoexcitation are reduced to colorfull viologen radicals. The crystals are so photochromic and change their color from yellow to green reversibly.