Synthesis and oxidation of hexafluoroisopropoxyborylferrocenes

Abstract

The ferrocenylboranes (BOhfip 2)Fc and 1,1′-(BOhfip 2) 2Fc were prepared (Fc = ferrocenyl, Ohfip = (CF 3) 2CH-O); 1,1′-(BOhfip 2) 2Fc was further oxidized giving [1,1′-(BOhfip 2) 2Fc] +[Al(OR F) 4] - by oxidation of 1,1′-(BOhfip 2) 2Fc with Ag +[Al(OR F) 4] -(R F = C(CF 3) 3). Their X-ray crystal structures were determined and give further information on the Fe-B interaction through the dip angles α*. In [1,1′-(BOhfip 2) 2Fc] +[Al(OR F) 4] -, this Fe-B interaction is enfeebled: the dip angles α* (0.3° and 5.4°) are significantly smaller than in (BOhfip 2)Fc (7.8°) and 1,1′-(BOhfip 2) 2Fc (8.0°), and the hexafluoroisopropoxy moieties are twisted out of the Cp plane by up to 66.1°. NMR and vibrational spectra support the crystal structure assignments. © 2012 IUPAC.