Reaction of electrophiles with manganese(I) and rhenium(I) alkoxide complexes: Reversible absorption of atmospheric carbon dioxide

Article abstract of DOI:10.1021/om00029a032

The transition metal alkoxides fac-(CO)₃(P-P)MOR [where M is Mn or Re, P-P is either 1,2-bis(diphenylphosphino)ethane (dppe) or 1,3-bis(diphenylphosphino)propane (dppp), and R is either CH₃, C₂H₅, or CF₃CH₂] react readily at room temperature with CO₂, CS₂, and PhNCO by insertion of these electrophiles into the metal-oxygen bond. The reactions with CO₂ leading to the corresponding carbonate complexes fac-(CO)₃(P-P)MOC(O)OR are of special interest; benzene solutions of the alkoxides can even absorb CO₂ from the atmosphere. All the carbonate complexes release CO₂ when argon is bubbled through solutions of them, regenerating the alkoxides. These equilibrium reactions make it possible to exchange the CO₂ of the carbonate complexes by treatment of them with CS₂ or PhNCO. Only the CO₂ reaction is reversible under mild conditions. When a solution of fac-(CO)₃(dppe)MnOC(O)OCH₃ is treated with CH₃NH₂ followed by CO₂ the metallourethane complex (CO)₃(dppe)MnOC(O)NHCH₃ is formed. The X-ray crystal structure of fac-(CO)₃(dppe)MnOC(O)OCH₃ is presented.