EPR Spectroscopy Study of the Radical Cation Cluster (η5-C5H5)(CO)5ReFePt(μ3-C=CHPh)(η2-Ph2P(CH2)2PPh2)

The chemical oxidation of the cluster CpReFePt(mu(3)-C=CHPh)(CO)(5)(dppe) (Cp = eta(5)-C5H5, dppe = eta(2)-Ph2P(CH2)(2)PPh2) resulted in a radical cation [CpReFePt(mu(3)-C=CHPh)(CO)(5)(dppe)](+center dot) that is sufficiently stable only at low temperature. An electronic structure of the radical cation was studied by EPR and following parameters were obtained by comparison of the experimental and model spectrum: g(x) = 2.070 g(y) = 2.0295 g(z) = 1.997; A(x)(P-31) = 17 A(y)(P-31) = 49 A(z)(P-31) = 35 (Gs);A(x)(Pt-195) = 62 A(y)(Pt-195) = 45 A(z)(Pt-195) = 105 (Gs). An unpaired electron is seen to be mainly concentrated on the iron atom (85-90%) and partially on the platinum atom (10-15%). Further transformation of the radical cation led to the formation of the binuclear complex Cp(CO)(2)RePt(mu-C=CHPh)(dppe) and the Fe-carbonyl fragment.