Rutgers–Camden graduate student Lisa Sibley logged in countless hours drawing some 800 molecules of an often-overlooked sigmatropic rearrangement into a molecular modeling program that corroborated with experiments performed by colleagues in a lab in Galway, Ireland.
Why engage in the time-consuming theoretical work involved in creating these molecular arrangements? Because the Rutgers–Camden research team is gaining knowledge on how molecules rearrange during reactions. They go through a transition state – like the lowest path to get over a mountain range – that can’t be easily pinned down by physical means alone.
The Rutgers–Camden and National University of Ireland researchers recently published their findings in the International Journal of Quantum Chemistry, Journal of Organic Chemistry and Tetrahedron Letters.
“For the most part, you can’t isolate the molecules we study because they are intermediate steps leading to the final product; that’s why certain theories help us visualize what’s extremely difficult to see using current spectroscopic techniques,” notes Sibley on her work in Luke A. Burke’s Rutgers–Camden lab on the 1,4-sigmatropic rearrangements.
“These theories help us understand how reactions are taking place, how bonds are forming, how bonds are breaking, and how molecules are orienting with respect to each other during a reaction,” she adds. “It’s very difficult to envisage these states without theoretical calculations. Knowing them lets us steer the reaction to different products.”
Burke, a professor of chemistry at Rutgers–Camden, was invited to conduct research in Oxford University’s Department of Theoretical Chemistry two decades ago and met his colleagues from nearby Galway, Ireland: Richard Butler and Patrick McArdle.
The Rutgers–Camden lab not only looks at the theoretical implications of molecules forming, but also how we humans might be consuming chemicals generated for industrial purposes now rampant in the atmosphere and our water. For instance, Burke is studying how PFOA, which was used in many different non-stick coatings, is currently mimicking the thyroid hormone in its molecular shape and static charge.
“There are reports in Britain that are linking this chemical to depression,” states Burke. “If the size, shape, and static charge of the molecules are the same, then we can think the biological reactions are too.”
The Rutgers–Camden researcher’s work doesn’t stop there; he is also tackling the global challenge to capture the sun’s rays and turn them into electricity. With independent researcher Fenton Heirtzler, Burke is in the early stages of identifying a new organic molecule, instead of silicon, to serve in solar cells and laser optical devices. While he won’t divulge too much about this exciting development, Burke does offer that recent results have been “promising” and have been accepted for publication in the International Journal of Quantum Chemistry, a prominent scholarly publication.
Communicating his complicated work to the general public can be a challenge; but it’s the safety of this public that motivates the Rutgers–Camden researcher.
“Millions of chemicals only react within a few dozen patterns. We can practice good molecular design and come up with new chemicals or figure out what they do inside living things. We chemists should not only have a sense of what we are working with, but a better sense of what others would take from us and release into the world,” Burke adds.
For the Rutgers–Camden chemist’s students, their scope for good chemistry has broadened tremendously. Sibley, who will be pursuing her doctorate in organic chemistry at the University of California, is grateful for her experience working in molecular design.
“Molecular modeling is another tool in my organic chemistry toolbox,” she adds, “I am indebted to Dr. Burke for equipping me with this knowledge.”
Media Contact: Cathy K. Donovan
(856) 225-6627
E-mail: catkarm@camden.rutgers.edu