Abstract:

Metal ions are ubiquitous in biology and aid in facilitate many enzymatic transformations. For instance, high–valent iron–oxido and –hydroxido species are proposed to be key intermediates in oxidative processes catalyzed by non-heme iron proteins. A subclass of these proteins contains bimetallic sites that house a FeFe core. To investigate the properties of both mono- and bimetallic cores, we have developed a symmetric multifunctional tripodal ligand framework containing phosphinic amido groups, which can stabilize high–valent metal centers, form hydrogen-bonding networks, facilitate intramolecular proton transfer, and provide an auxiliary binding-site for a second metal ion. This presentation will describe my efforts to access high-valent diiron oxido and –hydroxido species by a variety of synthetic routes. Details of the structural and spectroscopic properties will be discussed that were obtained by X-ray diffraction methods, electrochemical techniques, and electronic absorbance, electronic paramagnetic resonance, Mössbauer, and vibrational spectroscopies.