CHEMISTRY OF (PENTABENZYLCYCLOPENTADIENYL)IRON COMPOUNDS INCLUDING 17-ELECTRON DITHIOCARBAMATE COMPLEXES

C-5(CH(2)Ph)(5)H, C(5)Bz(5)H, 1, the precursor of the useful C(5)Bz(5) ligand that was introduced by Rausch, has been synthesized in 85% yie ld, a slight improvement over the 62% yield very recently reported by Rausch. [Fe(C(5)Bz(5))(CO)(2)], 2, also reported by Rausch, could be o btained in 72% yield as the only product of the reaction between 1 and [Fe(CO)(5)] at 90 degrees C for 4 days. Reaction of 1 with Br-2 gives [Fe(C(5)Bz(5))(CO)(2)Br], 3, in 84% yield. Photolysis of 3 in THF usi ng visible light in the presence of Na(+)S(2)CNMe(2)(-) (Na(+)dtc(-)) gives a 73% yield of [Fe(C(5)Bz(5))(CO)(eta(2)-dtc)], 4, whose oxidati on by [FeCp(2)](PF6-)-P-+ gives the 17-electron complex [Fe-III(C(5)Bz (5))(eta(2)-dtc)(NCMe)](PF6-)-P-+, 5, the precursor of [Fe(IV)Cp(eta( 2)-dtc)(2)](+)-PF6-, 7. Cyclic voltammetry studies of the C(5)Bz(5)-ir on complexes show that the electronic properties of C(5)Bz(5) are inte rmediate between those of C5H5 (CP) and C(5)Me(6) (Cp) and that C(5)B z(5) destabilizes paramagnetic iron complexes as opposed to the stabil izing property of Cp.