Calixochromes: Syntheses, structure and supramolecular effects of biphotochromic calix[4]arenes

Calix[4]arenes functionalized at the lower rim with photochromic dihydroind olizine unities gave a new family of calixarenes, the calixochromes, which show photochromism. The conformation and configuration of the new photochro mic calixarenes were investigated by NMR experiments. The structures of all compounds were calculated based on NOESY data. For the biphotochromic cali xochrome 3 in the 1,2 alternating conformation a deviation from linearity i n the Stern-Volmer plot was found indicating complexation between the calix ochrome and the quencher benzoquinone.