Norbornadiene/Quadricyclane (NBD/QC) and conversion of solar energy

Book chapter, 2022

This chapter presents the norbornadiene (NBD) molecule as a photoswitch. This bicyclic molecule is photoconverted to a high-energy metastable isomer quadricyclane (QC) via light-induced [2+2] cycloaddition reaction. NBD is widely used as a molecular photoswitch due to its easily tunable isomerization properties (e.g. isomerization quantum yield, onset of absorption, half-life of the quadricyclane, and energy-storage density) by the functionalization with different chromophoric substituents. The molecular solar thermal-energy-storage system (MOST) application and its design of heat-release devices based on the NBD/QC system have been strongly evolving in the last years. However, also several new applications start to develop, making this photoswitch a versatile compound.