The treatment of odd-electron species in the undergraduate curriculum includes discussion of radicals in organic chemistry and transition metal-containing compounds in both the inorganic and biochemistry lecture sequences. Although discussion of inorganic compounds with unpaired electrons is a vital component of the undergraduate chemistry syllabus, radicals are often quickly dismissed in the undergraduate organic chemistry curriculum as short-lived intermediates, ignoring the existence of stable radicals, and missing the opportunity to reinforce concepts in structure and bonding. Unfortunately, direct experimental evidence for odd-electron species and their reactivity are not usually presented at all. The project will purchase an Electron Spin Resonance (ESR) spectrometer for use in the undergraduate curriculum. This will facilitate the development and demonstration of important ideas in physical chemistry (analogy between ESR and NMR), organic chemistry (interpretation of electron-nuclear spin coupling as an extension of the concept covered in discussion of NMR), materials chemistry (role and nature of unpaired electrons in conducting polymers and conducting metal oxides), inorganic chemistry (elucidation of molecular structure, bonding theory, stability and the 18 electron rule) and biochemistry (redox behavior of metalloproteins). The instrument will allow us to develop and implement new experiments that will enhance students' understanding of fundamental ideas in structure and bonding. It will be used by 300 students per year in sophomore-level synthesis laboratory course, by junior and senior chemistry majors, and for undergraduate research. New experiments for the undergraduate laboratories are being developed as part of a curriculum reform in response to a change from a quarter based system to a semester based academic calendar. Treatment of ESR in the laboratory sequence offers a unique opportunity to explore new pedagogies for the treatment of odd-electron species, an area w hich we feel is currently lacking emphasis. As experiments are developed they will be made available for adoption elsewhere.
