Crucial Factors Regulating Site Interactions in Resin Supports Determined by Single Bead IR

Interactions between resin-bond reactive groups were determined by measuring the single bead IR signals sensitive to their association and dissociation. Our results strongly indicate that site separation and site interaction always occur and that they are in a dynamic equilibrium in resins. The highly dynamic nature of the site interaction was demonstrated by the lack of linker-length influence on site interaction. An increased competition for nearby sites or a reduced availability of the nearby sites all suppressed site interaction, indicating the importance of the availability of sites. Our results indicated that the less bulky microenvironment, the more reactive functional group, and the more available nearby sites are factors which favor site interaction.