Preparation, properties and reactions with sulfur dioxide in the solid state of complexes of the type [Mn(Ph2E(O)YE(O)Ph2)2(H2O)2](ClO4)2 (E=As, P; Y=C2H4, cis-C2H2). The formation of bis-sulfur dioxide complexes which contain both weakly bound and strongly bound sulfur dioxide

Abstract

Hexacoordinate manganese(II) perchlorate complexes containing diphosphine dioxide, diarsine dioxide or a mixed phosphine oxide/arsine oxide ligand, [Mn(ligand)2(H2O)2](ClO4)2, react in the solid state with sulfur dioxide to form the [Mn(ligand)2(H2O)2(SO2)2](ClO4)2 adducts, as shown by weight increases. One sulfur dioxide molecule is readily lost on exposure to air, but the second is much more strongly held and is only lost on heating to 65–108 °C. Absorption isotherms have been obtained for the uptake of two molecules of sulfur dioxide by [Mn(dpaeO2)2(H2O)2](ClO4)2 and of one molecule of SO2 by [Mn(dpaeO2)2(H2O)2(SO2)](ClO4)2 (dpaeO2= Ph2P(O)CH2CH2As(O)Ph2).