Syntheses and X-ray Crystal Structures of Five- and Six-Coordinated Iron(I) and Iron(II) Complexes with the Same (η⁵-C₅Me₅)Fe(dppe) Framework

The one electron reduction of Cp*Fe(dppe)(OSO 2 CF 3 ) ( 2 ) with cobaltocene gave the d 7 iron(I) Cp*Fe(dppe) ( 3, 90%) as thermally stable orange crystals, whereas the one-electron oxidation of 3 with ferrocenium hexafluorophosphate afforded the new d 6 iron(II) 16-electron complex [Cp*Fe(dppe)][PF 6 ] ( 4, 98%) isolated as an stable orange powder. The X-ray crystal structures of 3 and 4 show that their major structural difference concerns the “pyramidalization” of the metal center.