REDOX BEHAVIOR OF FERROCENE DERIVATIVES .2. BIS(ETA-5-TRICYCLO[5.2.1.02,6]DECA-2,5,8-TRIEN-6-YL)IRON AND RELATED MOLECULES

The series of ferrocene-like derivatives 5-11, in which the cyclopentadienyl rings are fused to bicyclic norbornane- or pinane-like fragments, has been studied electrochemically in order to test the ability of these derivatives to lose one electron as well as to quantify any stereoelectronic effects associated with coordination of the bicyclic moieties above or below the plane of the cyclopentadienyl rings. The X-ray structure of the cation bis(eta5-tricyclo[5.2.1.0(2,6)]deca-2,5,8-trien-6-yl)iron(III) ([5]+, as its TCNQ salt) has been determined, thus allowing us to evaluate the stereochemical reorganizations accompanying one-electron removal from the corresponding neutral iron(II) congener (5). The EPR spectra of all the electrogenerated cations [5]+-[11]+ have been recorded at liquid-helium temperature.