文摘
We report the synthesis and full characterization of the entire haloferrocene (FcX) and 1,1鈥?dihaloferrocene (fcXb>2b>) series (X = I, Br, Cl, F; Fc = ferrocenyl, fc = ferrocene-1,1鈥?diyl). Finalization of this simple, yet intriguing set of compounds has been delayed by synthetic challenges associated with the incorporation of fluorine substituents. Successful preparation of fluoroferrocene (<b>FcFb>) and 1,1鈥?difluoroferrocene (<b>fcFb>b><b>2b>b>) were ultimately achieved using reactions between the appropriate lithiated ferrocene species and N-fluorobenzenesulfonimide (NFSI). The crude reaction products, in addition to those resulting from analogous preparations of chloroferrocene (<b>FcClb>) and 1,1鈥?dichloroferrocene (<b>fcClb>b><b>2b>b>), were utilized as model systems to probe the limits of a previously reported 鈥渙xidative purification鈥?methodology. From this investigation and careful solution voltammetry studies, we find that the fluorinated derivatives exhibit the lowest redox potentials of each of the FcX and fcXb>2b> series. This counterintuitive result is discussed with reference to the spectroscopic, structural, and first-principles calculations of these and related materials.