Molecularly engineering homogenous catalysts

Abstract

A critical issue in the design of new 'Green' recoverable reusable catalyst is the separation strategies used for catalyst recovery. Using materials and solvents that are miscible at elevated temperature but phase separate at low temperature we have developed new strategies for homogeneous catalyst recovery. Poly (N-isopropylacrylamide) and poly (N-octadecylacrylamide) supports, for example, yield recoverable catalysts that are selectively soluble in the lower (polar) phase and the upper (non-polar) phase, respectively. To explore the phase distribution continuum for other polymers, we have prepared poly (N-acryloxysuccinimide) (PNASI) and used this reactive polymer to prepare dye-labeled C3-C18-poly (N-alkylacrylamide) supports. UV analysis of these dye-modified polyacrylamides' phase solubility at ambient and elevated temperature will be described. Such experiments probe the phase behavior of these polymer supports as a function of side chain length and can be accomplished in a combinatorial fashion using PNASI as the common starting material. The potential for such supports in catalysis will be described.