Synthesis and Characterization of Stable Iron Pentacarbonyl Radical Cation Salts.

The open-shell iron pentacarbonyl cation [Fe(CO) 5 ] .+ was isolated by deelectronation, i.e., the single-electron oxidation of the parent neutral Fe(CO) 5 using [phenazine F ] .+ as the [Al(OR F ) 4 ] - and [F-{Al(OR F ) 3 } 2 ] - salt (R F =C(CF 3 ) 3 ; phenazine F =perfluoro-5,10-bis(perfluorophenyl)-5,10-dihydrophenazine). [Fe(CO) 5 ] .+ [Al(OR F ) 4 ] - was fully characterized (scXRD analysis, IR, NMR, EPR, 57 Fe spectroscopy, CV and SQUID magnetization study) and, apart from being a compound of fundamental interest, may serve as a precursor for low-valent iron coordination chemistry.