Ferrocene-Containing Organometallic Macrocycles and Cyclic Polymers

Significance

There are few methods in polymer synthesis that give exclusively cyclic polymers. Cyclic systems have the ability to display interesting properties, including rotaxane structures in blends with other linear polymers. The authors report the first synthesis of ferrocene-based cyclic polymers. Upon photolysis of ferrocenophane 1 in the presence of a stoichiometric quantity of Me₂bpy, the reaction yielded a mixture containing cyclic polymer 2, cyclic pentamer 3 and cyclic hexamer 4. Cyclic pentamer and the cyclic hexamer were characterized using NMR spectroscopy and X-ray crystallography.