Soluble polymer supports as ligands for metal sequestration and catalysis

The development of soluble polymers as ligand and catalyst supports is described. These polymeric ligands are synthesized by radical polymerization of monomers such as acrylamides, styrenes and vinyl ethers. The polymers are designed to have specific solubility characteristics and are useful in different separation schemes. For example, poly(N-isopropylacrylamide) is soluble in room temperature water but will precipitate from aqueous solution. Ligands such as hydroxamic acid, hydroxypyridinone, and imidazole are combined with the polymer and shown to be effective ligands for metal sequestrations. The polymer-bound complexes are recovered by thermal precipitation and analysis of the supernatents show complete removal of the trace metals. Extending the length of the acrylamide side chain from three carbons to 18 carbons alters the solubility of the polymer, allowing it to dissolve in non polar solvents like heptane. This support is useful in thermomorphic separation strategies. Metal sequestering ligands attached to this poly(N-octadecylacrylamide) (PNODAM) support were successful in complexing metals in thermomorphic systems.;In a similar way, PNODAM and poly(maleic anhydride-c-octadecyl vinyl ether) (PMAOVE) supports were shown to be useful vehicles for recovering catalysts. SCS palladacycles attached to the PNODAM support were successfully used to catalyze Heck reactions in thermomorphic systems. PMAOVE supports were applied in latent biphasic systems for the formation of oxazolines.;Investigations of SCS palladacycles led to the development and synthesis of electronically varied organometallic complexes. The complexes were studied to elucidate their mechanism of catalysis. Through a series of experiments, including rate comparisons, Hammet plots, and Hg poisoning experiments, it was determined that the SCS complexes act as a source of Pd colloids. These colloids appear to be the actual catalysts in the reaction.