The cationic secondary phosphine complexes [CpM(CO)(L)(PR 2 H) + X − (M=Ru, PR 2 H=PPh 2 H, PPhH 2 , L=CO; M=Fe, PR 2 H=PPh 2 H, L=CO, MeC≡CMe, C 2 H 4 ; M=Mn PR 2 H=PCy 2 H, PPr 2 H, L=NO; X − =BF 4 − , PF 6 − ) and [(η 7 -C 7 H 7 )(CO) 2 Mo(PCy 2 H)]PF 6 , prepared by following literature procedures for the synthesis of their PPh 3 analogues, react with Pt(C 2 H 4 )(PPh 3 ) 2 to give [Cp(L)M(μ-PR 2 )(μ-H)Pt(PPh 3 ) 2 ]X and [(η 7 -C 7 H 7 )(CO)MO(μ-PCy 2 )(μ-H)Pt(PPh 3 ) 2 ]X as the final products