The doubly azobenzene-chain lower-rim substituted calixarenes 6-9 were prepared, followed by the doubly bridged biscalixarenes 10 and 11. All are photoresponsive and detailed studies of the E⇌Z photoisomerization and the Z→E thermal isomerization in 6 and 10 were carried out using UV and 1H NMR spectroscopic techniques. The three (EE, EZ and ZZ) isomers of 6 and 10 were isolated or enriched and fully characterized by 1H NMR. Kinetic analyses of these transformations of 6 were carried out and revealed a concentration dependent behavior and an interesting sequential course of its photoisomerization.
|Number of pages||8|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|State||Published - 29 Feb 2000|
- Bridged calixarenes
- Supramolecular chemistry