The approach to 4d/4f-polyphosphides

The first 4d/4f polyphosphides were obtained by reaction of the divalent metallocenes [Cp*(2)Ln(thf)(2)] (Ln = Sm, Yb) with [{CpMo(CO)(2)}(2)(μ,η(2:2)-P(2))] or [Cp*Mo(CO)(2)(η(3)-P(3))]. Treatment of [Cp*(2)Ln(thf)(2)] (Ln = Sm, Yb) with [{CpMo(CO)(2)}(2)(μ,η(2:2)-P(2))] gave the 16-membered bicyclic compounds [(Cp(2)*Ln)(2)P(2)(CpMo(CO)(2))(4)] (Ln = Sm, Yb) as the major products. From the reaction involving samarocene, the cyclic P(4) complex [(Cp*(2)Sm)(2)P(4)(CpMo(CO)(2))(2)] and the cyclic P(5) complex [(Cp*(2)Sm)(3)P(5)(CpMo(CO)(2))(3)] were also obtained as minor products. In each reaction, the P(2) unit is reduced and a rearrangement occurred. In dedicated cases, a P–P bond formation takes place, which results in a new aggregation of the central phosphorus scaffold. In the reactions of [Cp*(2)Ln(thf)(2)] (Ln = Sm, Yb) with [Cp*Mo(CO)(2)P(3)] a new P–P bond is formed by reductive dimerization and the 4d/4f hexaphosphides [(Cp*(2)Ln)(2)P(6)(Cp*Mo(CO)(2))(2)] (Ln = Sm, Yb) were obtained.