REACTIVITY OF SOME LADDER TYPE COMPLEXES UNDER CONDITIONS OF METALATION

The behavior of binuclear ''ladder'' type complexes FpL, where Fp = Cp (CO)(2)Fe, L = p-MeC6H4Cr(CO)(3) (4), CH2C6H5Cr(CO)(3) (5), and p-FpC( 6)H(4)Cr(CO)(3) (6), under conditions of metallation was studied. Unli ke compounds 5 and 6, the sigma-bound ligand L in compound 4 migrates from the iron atom to the cyclopentadienyl ring to give complexes Me(C O)(2)FeC5H4-C6H4(p-Me)Cr(CO)(3). The electrochemical reduction potenti als of the complexes 4-6 and the rearrangement products were measured. The migration activity of L is determined by the ease of reductive cl eavage of the Fe-L bond and the susceptibility of the system to underg o intramolecular electron transfer from the Cp ligand to the aromatic ring.