University of California, Santa Barbara
Faculty Sponsor's Department(s):
Chemistry and Biochemistry
Synthesis of Imidazolin-2-iminato Iron Complexes
The 1973 Nobel Prize in Chemistry was awarded to Ernst Otto Fischer and Geoffrey Wilkinson for their discovery of the “sandwich-like” bonding structure between the cyclopentadienide (Cp– = η5-C5H5) ligands and iron in ferrocene [Cp2Fe]. This landmark discovery lead to rapid growth in the field of organometallic chemistry. Even today, metal complexes with Cp– ligands (i.e., metallocenes) are studied extensively. Their bonds are remarkably strong because of Cp–’s ability to contribute six bonding electrons (1σ:2π e–’s) to the metal. In our laboratory, we have been investigating the coordination chemistry of imidazolin-2-iminato (ImN–) ligands, which comprise a particularly nucleophilic class of iminic-type donors. Interestingly, the extreme resonance form of ImN– can be considered an isolobal analog of Cp–. Capitalizing on the electronic structure relationship between these two ligand systems, we have set out to synthesize the novel ferrocene-type complex (ImN)2Fe. The target complex is predicted to mimic the behavior of ferrocene by exhibiting similar redox chemistry, while also possessing significant steric and electronic flexibility. Synthesis and characterization of this complex will allow us to further compare and contrast the properties of ImN– and Cp–. Metathetic routes for the synthesis are currently being explored, and progress towards this end will be presented.