REACTIVITY OF MANGANESE(II) COMPLEXES OF DERIVATIVES OF 2-METHYLPYRIDINE-N-OXIDE TOWARDS SULFUR-DIOXIDE

The metallic complexes [Mn(2-PyCO)(n)X(2)(H2O)(x)] (2-PyCO = 2-methylp yridine-N-oxide, n = 1-3, X = Cl, Br, I and NO3 and x = 0-3) have been synthesized and their reactions with sulfur dioxide, both in the soli d state and as toluene slurries at room temperature, have been investi gated. Furthermore, the reactivity of these complexes with sulfur diox ide at high temperature has been studied by thermogravimetric analysis (TGA), the temperature range of study depending critically on the mel ting point of the initial complexes. All the complexes, except the chl oride derivative, react with sulfur dioxide at room temperature. Incre ase in the temperature, in general, disfavours this reaction and the a mount of sulfur dioxide fixed decreases at high temperature. Finally, desorption studies have been carried out in order to discover whether the reaction of the precursors with sulfur dioxide is reversible. Copy right (C) 1996 Elsevier Science Ltd