Skip to Main Content

John Weaver, Ph.D.

 

Chemistry 2003

Area of Doctoral Study: Chemistry
Undergraduate Institution: Washington College

Research Advisor: Theodore Budzuchowski, Ph.D

Current Position: Assistant Research Professor and EPR Core Scientist, College of Pharmacy,  University of New Mexico, Albuquerque

Description of Research

My research interests lay in the areas of inorganic and environmental chemistry with a strong emphasis on developing synthetic skills. One specific issue that I hope to address during my graduate work involves the rational development of “green” catalysts for a variety of industrially important processes.

There are several approaches. In one case, I hope to convert known and popular transition metal catalysts into aqueous compatible forms. One tactic, which has already been demonstrated successfully, involves modification of the ligands in remote regions so that they strongly interact with water. The catalytic activity of the transition-metalcomplexes they form are not adversely affected but their aqueous solubility is greatly increased. A variety of new surfactant-type phosphines and cyclopentadienes have already been targeted. Alternatively, I hope to synthesize a variety of new catalysts which bear dramatically different ligands such as water, hydroxide, or amines. Systematic testing of their efficacy would also be a natural extension of this synthetic effort. We have recently discovered that, while Wilkinson’s catalysts is inactive towards hydroformylation or hydrogenation of olefins in water, modification of solvent medium to include a small percentages of triethylamine results in dark brown solution which homogeneously catalyzes the conversion of olefins to alkanes and aldehydes under modest pressures of hydrogen and carbon monoxide. We are actively pursuing the exact nature of the transition metal component(s) of this medium in the hopes of gaining better insight into the nature of the catalysis. Further modifications would likely result in improvements in our observed turnover rates.

One last approach is to introduce additives to the solvent medium, such as surfactants or membrane-forming phospholipids. These would compatibilize the transition-metal complex by enveloping it in a hydrophobic pocket without altering its reactivity. Enhanced catalytic rates for catalytic transformations of hydrophobic substrates may be anticipated based on the reduced volume of the actual reactive space as compared to the volume of the entire medium. I hope to synthesis several new “polymerized” micelles which are “permanent”(not subject to dynamic equilibria involving micelle formation and breakdown) in water and thus confine the catalysts to this region. Our use of surfactant phosphines in the coordination sphere of the transition metal compliments this objective nicely.