1,4-Benzoquinone (quinone) is one of the most interesting fundamental π-electron systems because its high electron affinity and photoreactivity. 1–3 Calixquinones 4,5 (eg1) and calixhydroquinones 4–7 (eg2 and 3), which are members of the calixarenes, 8 have received intense interest due to their electrochemical reactivities, conformational behavior in solution, structures in the solid states, and incorporation of metal ions (Chart 1). However, silicon-bridged calixquinones ...
