ELECTRON-ELECTRON SPIN-SPIN SPLITTING

Most chemistry textbooks treat free radicals as transient reactive species, so it was surprising to GRE (then an undergraduate student) that William N. Lipscomb suggested that Alex Kaczmarczyk might have produced a stable radical of a boron hydride in 1961. This hypothesis, which turned out to be wrong, led to a particularly memorable visit to Gus Maki's lab to search for an EPR signal. Later, while serving in the Navy GRE was perplexed by Chemical Abstracts entries about “spin sounds.” Since the original articles were not accessible then, it took some time to realize that this was a mis-translation of the French sonde! The next exposure to EPR came in an assignment as a first-year graduate student to develop, at the initiative of Richard Holm, new undergraduate laboratory exercises that combined synthesis of substituted quinones, electrochemical generation of the semiquinone radicals, and EPR. This was done on the first Varian E3. One day, while browsing in the MIT library, all of these pieces came together when an article about nitroxyl radicals was found serendipitously. This happened about the time that GRE met SSE, also a graduate student at MIT, and we got manied. We developed the idea of making complexes that included nitroxyl radicals in ligands to paramagnetic transition metals (1). If our proposal to work on this as part of our Ph.D. thesis work had been accepted, the work probably would have stopped when we graduated. However, the proposal was rejected as not worth working on, so we could only think and plan for the future. We came to the University of Denver in part because the school was willing to invest in an EPR spectrometer for someone who was not an EPR spectroscopist. Our research program owes a lot to Dwight M. Smith, the Chairman of the Department, who believed in our quest, and gave support at critical junctures…