Carbon monoxide release properties and molecular structures of phenylthiolatomanganese(I) carbonyl complexes of the type [(OC)4Mn(μ-S-aryl)]2.

Abstract

Several phenylthiolatomanganese carbonyl complexes of the type [(OC)4Mn(μ-SR)]2 (R = Ph (), C6H4-4-CH3 (), C6H4-4-CF3 (), C6H4-4-F (), C6H4-4-Cl (), C6H4-4-OMe (), C6F5 (), and CH2C6H4-4-Cl ()) have been prepared via the reaction of Mn2(CO)10 with diaryldisulfane or via the reaction of [(OC)5MnBr] with arylthiols. These complexes lose two carbon monoxide molecules quite easily yielding tetranuclear [(OC)3Mn(μ3-SR)]4 (). Derivatives with fluoro-substituted aryl groups commonly form mixtures of dinuclear and tetranuclear which can quantitatively be converted to by heating of the corresponding reaction mixtures. A unique trinuclear structure is found for the mesityl derivative [(OC)4Mn(μ-SMes)]3 () which is maintained in solution as verified by IR and NMR spectroscopy. Traces of an already known dinuclear by-product of the type [(OC)3Mn(μ-SC6H3(-4-Me)-2-SC6H4-4-Me)]2 () have been structurally characterized. The suitability of [(OC)4Mn(μ-SPh)]2 () as a CO releasing molecule (CORM) for the administration of carbon monoxide has been studied. Two CO molecules are released upon dissolving in strongly Lewis basic solvents L, yielding [(OC)3Mn(L)(μ-SPh)]2, which liberates all the remaining CO molecules upon irradiation (photoCORM behavior).