CHAPTER 13: The Application of Thiol‐Ene/Yne Radical Click Chemistry in Surface Modification and Functionalization

Thiol‐ene/yne radical addition reactions, which possess the classical characteristics of click chemistry, have been emerging as facile and efficient coupling procedures in various fields. Different from the typical Huisgen azide‐yne 1,3‐dipolar cycloaddition, thiol radical click chemistry can be performed without the use of metal catalysts, which is superior in biological application. Additionally, the utilization of metal‐free thiol radical click reactions in the synthesis of chromatographic stationary phases can avoid having residual metal ions in the materials which is detrimental in chromatographic separation, especially for analytes that can form chelates with metal ions. In this chapter, the application of the radical‐mediated thiol‐ene/yne click reaction in surface modification and functionalization iss introduced. Thiol click chemistry has been successfully utilized in surface engineering and patterning, the modification of solid surface with alternative properties, the immobilization of macromolecules, etc. In addition, thiol radical click chemistry has been efficiently used in the preparation of chromatographic stationary phases, including chiral (ion‐exchange) materials, reversed‐phase stationary phases, mixed‐mode stationary phases and hydrophilic interaction liquid chromatography (HILIC) stationary phases.