The solid state structures of transition metal complexes and their interactions with gaseous sulphur dioxide

The manganese halide complexes, [Mn2(μ-dppO2)4X2]X2.2H2O (X = Cl, Br, I; dppO2 = Ph2P(O)(CH2)3P(O)Ph2) have been synthesised and structurally characterised by single crystal X-ray diffraction. Powder diffraction studies of the complexes have been performed at room temperature and at 120°C. The reactivity of the complexes towards sulfur dioxide has been studied using thermogravimetric techniques and X-ray powder diffraction and two sulfur dioxide adducts have been crystallographically characterised; that of [Mn2(μ-dpp02)4(NCS(2(NCS)2.2S02 and [Mn2(μdpp02) 4Br2]Br2.2CH30H.S02. Thermodynamic studies have been performed on the reactivity of the manganese complexes [Mn2(μ-dpp02)4X2]X2 (X = Cl, Br, I, NCS) in order to calculate approximate values for the enthalpy of formation of the sulfur dioxide adducts.