The insertion of carbon dioxide into theMn-O bond of
fac-(CO)
3(dppe)MnOCH
3 (
1) was observed to occur instantaneously at -78
C by in situinfrared spectroscopy. The product of carboxylation of
1,
fac-(CO)
3(dppe)MnOC(O)OCH
3 (
2), underwent decarboxylation with a first-order rate constant of 1.49 × 10
-4s
-1 at 23
C. The kinetic parameters for this process weredetermined by trapping the intermediate produced uponCO
2 extrusion, complex
1, with COS to provide the verystable
fac-(CO)
3(dppe)MnSC(O)OCH
3 (
3) derivative. Thestructure of
3 was determined by single-crystal X-raydiffraction analysis, establishing the presence of theMn-S bond.