Used as a key monomer in the synthesis of high-performance polymers, particularly in the production of sulfonated poly(arylene ether sulfone)s for proton exchange membranes in fuel cells. Its spirocyclic structure enhances thermal stability and mechanical strength while promoting efficient proton conductivity with low fuel crossover. Also employed in the development of advanced materials for lithium-ion batteries and electrochemical devices due to its rigid, hydroxyl-functionalized framework that supports stable radical formation and electron transport. Additionally, serves as a building block in optoelectronic materials, contributing to the design of transparent, durable films for sensors and display technologies.