* 1977–1983	          Assistant Professor: Department of Chemistry, SUNY at Albany, Albany, NY
* 1983–1987	          Associate Professor: Department of Chemistry, SUNY at Albany, Albany, NY
* 1987–1990	          Professor: Department of Chemistry, SUNY at Albany, Albany, NY
* 1990–present	  Professor: Department of Chemistry, Johns Hopkins University, Baltimore, MD
* 2009–present Professor: Department of Bioinspired Science, WCU Program, MOBIC (Metal Oxygen BioInspired Chemistry) Group Ewha Womans University Seoul, KOREA