Molecular Assembly and Disassembly:  Novel Photolabile Molecular Hosts

A new approach to the assembly and photochemical disassembly of molecular hosts is developed. It is based on photoinduced fragmentation in hydroxyalkyl dithianes and utilizes a novel spiro-bis-dithiane as a photolabile molecular tether to link two formylated macromolecular blocks, e.g., formyl calixarenes or formyl dibenzocrown ethers. A key feature of this molecular system is that after an assembly−disassembly cycle the starting macromolecular blocks are recovered intact and can be used again.