A comparison of the efficiencies of polymer-supported phosphine and phosphine oxide complexes of manganese(II), MnX2(P C6H4PPh2) and MnX2{P C6H4P(O)Ph2}n(n= 2 or 4; X = Cl, Br, or I), for the absorption of sulphur dioxide

Abstract

Diphenylphosphinated poly(styrene–divinylbenzene), [graphic omitted]C₆H₄PPh₂(L), reacts readily with the manganese(II) salts, MnX₂(X = Cl, Br, or I) under anhydrous conditions to form MnX₂(L)_n(X = Cl or Br, n= 1; X = I, n= 1.5). The similar reaction of the phosphine oxide, [graphic omitted]C₆H₄P(O) Ph₂(L′), affords the complexes MnX₂(L′)_n(X = Cl, n= 1; X = Br or I, n= 1.5) and MnX₂(L′)_m(X = Cl or Br, m= 3; X = 1, m= 5), depending upon reaction conditions. Both the phosphine and phosphine oxide complexes absorb SO₂ either when suspended in a mixture of toluene and dichloromethane (60:40 v/v), or in the solid state. In both cases the efficiencies are found to be in the order I > Br ∼ Cl. Sulphur dioxide binding is irreversible for the phosphine complexes, but partially reversible with phosphine oxide derivatives.