He is presently the Albert A. Michelson Distinguished Service Professor Emeritus.
His research interests have included laser spectroscopy in supersonic molecular beams and jets, the structure of van der Waals molecules, energy transfer in weakly bound molecular systems, bichromophoric organic molecules, and multi-photonionization spectroscopy.
In 2005, he was chair of the Universities Science Policy Council, a group responsible for guiding high level scientific directions at Argonne National Laboratory, awarding joint appointments, and negotiating student and faculty access to National User Facilities at Argonne.
[1] After 2007, he was named by the University of Chicago Vice President for Research and for National Laboratories, CEO of UChicago Argonne, LLC and a Member of the Board of Directors of Fermi National Accelerator Laboratory.
He is the past chairman of the chemistry department at the University of Chicago, where he played an important role as a leader for planning the Gordon Center for Integrative Science.