SYNTHESES AND REACTIVITY WITH SULFUR-DIOXIDE OF MANGANESE(II) COMPLEXES CONTAINING PYRIDINE-N-OXIDE AND 4-METHYLPYRIDINE-N-OXIDE AS LIGANDS

The complexes MnL(n)X(2)(H2O)(m) (L = pyridine-N-oxide, 4-methylpyridi ne-N-oxide; X = Cl, Br, I, NO3; n = 2-4; m = 0-4) have been prepared. Most of these complexes react with sulfur dioxide in the solid state a nd as toluene slurries at room temperature, yielding adducts of differ ent stoichiometry, but an increase in the temperature clearly disfavou rs the interaction. The iodide derivatives of pyridine-N-oxide show th e most interesting behaviour, being those which posses the ability of fixing a major quantity of SO2. The studies of the reversibility of th e reaction (desorption studies) show that none of the adducts fix all the SO2 in a reversible way and more than one binding mode being prese nt for most of the adducts studied here. Copyright (C) 1996 Elsevier S cience Ltd