Cyclodextrins in polymer synthesis:: Free radical polymerization of β-cyclodextrin complexes of photosensitive mesoionic 6-oxo-1,6-dihydropyrimidin-3-ium-4-olates in aqueous medium

Solid mesionic 2-[2-(isopropenylcarbonyloxy)ethylthio]-1-methyl-6-oxo-3-phenyl-5-propyl-1,6-dihydropyrimidin-3-ium-4-olate was complexed in water using beta-cyclodextrin (beta-CD) and randomly methylated beta-CD, which resulted in polymerizable complexes with 2:1 stoichiometry. The beta-CD complex was characterized using H-1 NMR, ROESY NMR and UV spectroscopy. Polymerization of the complex prepared from methylated beta-CD led to a photosensitive polymer, which precipitated during polymerization and was nearly free of CD. Polymerization was carried out with a water-soluble redox initiator. In addition, a copolymer with methyl methacrylate was prepared from the complexes, which showed a different mass-dependent distribution in the incorporation in comparison to a copolymer prepared without CD in organic solvents.