Reactions of ditertiary phosphines with η6-arenetricarbonylmanganese cations

Article abstract of DOI:10.1016/0022-328X(91)86349-U

Ditertiaryphosphines PPh2(CH2)nPPh2 (n = 1-3) react at room temperature with the η⁶-arenetricarbonylmanganese cations <(η⁶-XYC6H4)Mn(CO)3>⁺ (Ia, X = Y = H; Ib, X = Me, Y = H) by monocarbonyl substitution an formation of <(ν⁶-XYC6H4)Mn(CO)2(η¹-PPh2(CH2)nPPh2)>⁺.Prolonged refluxing results in metal-ring bond breaking and formation of cis- and trans-2-PPh2CH2PPh2)2>⁺ and trans-2-PPh2(CH2)2PPh2)2>⁺.Activation of a carbonyl group in <(η⁶-XYC6H4Mn(CO)2(η¹-PPh2(CH2)nPPh2)>⁺ by TMNO gives the series of chelate complexes <(η⁶-XYC6H4Mn(CO)(η²-PPh2(CH2)nPPh2)>⁺ (n = 1 - 3).The X-ray structure of the chelate with n = 3 is reported.In the case of <(η⁶-XYC6H4)Mn(CO)3>⁺ (Ic, X = Cl, Y = H); Id, X = Cl, Y= Me), formation of fac-Mn(CO)3(η²-PPh2(CH2)nPPh2Cl (n = 1, 2) occurs, in a reaction analogous to that with monophosphines, see D.A.Brown, W.K.Glass and K.M.Kreddan, J.Organomet.Chem., 413 (1991) 223, but there was no evidence for ring adducts as intermediates.