Liquid and Photoliquefiable Azobenzene Derivatives for Solvent-free Molecular Solar Thermal Fuels

A series of liquid and photoliquefiable azobenzene (Azo) derivatives (Azo-Cn-Br) have been synthesized for molecular solar thermal fuels. Each of the liquid and photoliquefiable azo derivatives shows a high degree of isomerization, a fast isomerization rate, a long half-life, an appropriate energy storage density, and a solvent-free charging and discharging process. The photoliquefied azo derivatives can isomerize upon UV light irradiation at low temperatures to give the UV-charged azo ones. Therefore, the phase transition enthalpy is stored simultaneously along with the isomerization enthalpy. The UV-charged azo derivatives are capable of releasing heat under the manipulation of blue light.

Automated summary

A series of liquid and photoliquefiable azobenzene derivatives have been synthesized for molecular solar thermal fuels. These derivatives exhibit high isomerization, fast isomerization rate, long half-life, appropriate energy storage density, and solvent-free charging and discharging process. The photoliquefied azo derivatives can undergo isomerization upon UV light irradiation at low temperatures, storing both the phase transition enthalpy and isomerization enthalpy, and can release heat under blue light manipulation.