Inspiration strikes in many forms, and in the case of Paul J. Chirik, the Peter J. W. Debye Professor of Chemistry at Cornell University, some might say the most notable research in his young career was a product of pure thriftiness. Chirik, 35, has designed a class of iron compounds that could be inexpensive and environmentally friendlier alternatives to the catalysts used in a range of industrial processes.
"The joke around here is that I was too cheap to buy rhodium," Chirik says. He thought it would be a cool trick to mimic more expensive metals like iridium and rhodium by using iron. "It was an interesting chemical problem that also had potential practical significance," he adds.
Chirik's lab has figured out how to store electrons in the ligands of iron compounds and then coax a reversible transfer of the electrons between the ligand and metal. The electronic structure of the resulting class of reduced bis(imino)pyridine iron compounds could prove extremely useful in olefin hydrogenation and hydrosilylation.
"Chirik's iron catalysts exhibit activities and selectivities that rival traditional rhodium compounds and thus represent a major breakthrough in the field that has attracted interest from major commodity and specialty chemical firms," a colleague notes.
Chirik first got interested in organometallic chemistry as a freshman at Virginia Polytechnic Institute & State University, when chemistry professor Joseph S. Merola took him into his lab. Chirik had been waffling between chemistry and history as his major, but Merola sat down with the student almost daily to discuss data, and soon Chirik was hooked. As an undergraduate, he studied organometallic catalysis in water at a time when conventional wisdom dictated those reactions had to be done in a dry-box. As a graduate student at California Institute of Technology, he shifted his focus to polymerization catalysis, where his work to make petroleum feedstock more efficient predated the current swell of interest in energy conservation.
Today, in addition to his work on iron catalysts, Chirik is exploring ways to exploit readily available atmospheric nitrogen to generate more valuable products under mild conditions. His group has discovered a zirconium compound that, at room temperature, combines nitrogen and hydrogen and ultimately releases free ammonia when heated.
"Well before the current media fervor about resource conservation and economic sustainability, Chirik's group was focused on the challenge of improving nitrogen fixation—a chemical transformation whose current energy requirements render crop fermentation products such as ethanol too energetically expensive to serve as alternatives to fossil fuels," a colleague says.
Chirik's research has led him to publish more than 50 papers in the past six years and receive a range of professional accolades, including being named a David & Lucille Packard Fellow in Science and Engineering, and a Cottrell Scholar and being given a National Science Foundation Career Award in 2003. He has also been recognized for his devotion to turning others on to the magic of chemistry: He was named the Camille Dreyfus Teacher Scholar in 2006, and he received the Stephen & Margery Russell Distinguished Teaching Award in 2005.