Reactivity of Mn(II) and Cu(II) adducts containing 2, 6-dimethylpyridine N-oxide with SO2

摘要

Adducts of accurate formula MX2 (2, 6-MepyO)2(H2O)n (M=Mn, Cu; 2,6-MepyO=2, 6-dimethylpyridine N-oxide;X=Cl, Br, I and NO3; n=0,2,3,6) react with SO2 in the solid stateand in toluene slurries at room temperature to yield SO2 adducts ofdifferent stoichiometry. The medium of the reaction influences theability of the adducts to bind sulphur dioxide and with usually canretain a greater quantity of SO2 in toluene slurries than in the solidstate. An increase in the temperature disfavours the reaction in thesolid state. Desorption studies were performed in order topostulate a coordination mode for the bound sulphur dioxide. Thisstudy, as well as analytical and spectroscopic data, allow us tosuggest that the SO2 is bridging between metal centres and/or isbound to the neutral ligand (mean) in most of the SO2 adducts.