Preparation of photoresponsive cyclobutane-1,2-dicarbonyl-capped 2.n diazacrown ethers by intramolecular [2 + 2] photocycloaddition, and their highly selective complexation with lithium cation

Abstract

Photoresponsive cyclobutane-1,2-dicarbonyl-capped 2.n diazacrown ethers were prepared by the intramolecular [2 + 2] photocycloaddition of p,p′-trimethylene dicinnamoyl-capped 2.n diazacrown ethers; the cyclobutane-1,2-dicarbonyl-capped 2.1 diazacrown ether showed a highly selective complexing ability for the lithium cation.