Manganiophosphonium-Salze: Synthese, Eigenschaften und Struktur von Komplexen des Typs [CpMn(CO)(NO)PPh2H]BF4 und [Cp′Mn(CO)(NO)PPh2R]X (R = H, CH3, {CpMn(CO)(NO)}; X = BF4, PF6)

Abstract

The reaction of [Cp′Mn(CO)2NO]X (Cp = C5H5, C5H4Me = Cp′; X =BF4, PF6) with PPh2H leads to the formation of the diphenylmanganiophosphonium salts [{CpMn(CO)NO}PPh2H]X, which can be deprotonated by DABCO to give the not isolable manganiophosphane {CpMn(CO)NO}PPh2. This reactive intermediate, however, can be methylated by MeI and CF3SO3Me or organometallated by C5H5Fe(CO)2Cl to yield the phosphonium salts [{Cp′Mn(CO)NO}PPh2Me]PF6 and [{Cp′Mn(CO)NO}PPh2{C5H5Fe(CO)2}]PF6, respectively. The methyl derivative is deprotonated by πBuLi to give the unstable methylene phosphorane {Cp′Mn(CO)NO}PPh2=CH2, an organometallated phosphorus ylide. The in situ from [{Cp′Mn(CO)NO}PPh2H]BF4 generated phosphane {Cp′Mn(CO)NO}PPh2 is oxidized by epoxycyclohexane to give the intermediate oxophosphorane {Cp′Mn(CO)NO}P(O)Ph2, which reacts with the still available starting material to yield the first dimanganiodiphenylphosphonium salt [{Cp′Mn(CO)NO}2PPh2]BF4. The compounds have been characterized by spectroscopic (IR, NMR, MS), analytical (C, H, N) and X-ray diffraction investigations ([{C5H5Mn(CO)NO}PPh2H]BF4, [{Cp′Mn(CO)NO}PPh2Me]BF6, [{Cp′Mn(CO)NO}2PPh2]-BF4).