PROGRESSION OF ORGANIC-REACTIONS ON RESIN SUPPORTS MONITORED BY SINGLE BEAD FTIR MICROSPECTROSCOPY

We report the time courses of five solid-phase reactions obtained usin g single bead FTIR microspectroscopy. This time-resolved information a ided in the determination of the required reaction time, the nature of the solid-phase reaction, and resin property, effectively assisting i n the initial phase of our combinatorial chemistry efforts. Our result s showed that solid-phase organic reactions proceed faster than genera lly speculated. In addition, we have shown that reactions on the surfa ce and in the interior of the bead occur at the same rate for reaction s studied. The reaction on the TentaGel resin was shown to be not fast er than reactions on Wang resin, suggesting that the diffusion of the substrate into polystyrene bead copolymerized with 1% divinylbenzene i s not rate-limiting. Finally, the capability of obtaining IR spectra f rom the partial surface of a single bead demonstrated the femtomolar d etection limit of single bead FTIR microspectroscopy.