Norbornadiene–quadricyclane – an effective molecular system for the storage of solar energy

The results of studies on intramolecular interconversions in systems of norbornadiene ⇄ quadricyclane and their derivatives are classified and discussed. The mechanisms of the forward photoreaction and reverse thermal process in relation to the nature of the substituents and carbocycles, type of sensitiser and catalyst, and properties of the medium are discussed in detail and classified. An analysis is made of the influence of these factors on the spectroscopic, kinetic, and thermodynamic properties of this system as an accumulator and converter of light energy. Methods of improving its characteristics – light absorption, the quantum yield of the photoreaction, and stability of the photoproduct – have been established. The bibliography includes 188 references.