Complexes of the form (tfacacen)Mn^IIIX (tfacacen = N,N^' -bis(trifluoroacetylacetone)-1,2-ethylenediimine) where X = Cl, N₃ act as useful mechanistic analogues to the active chromium (III) salen catalytic systems for the coupling of CO₂ and epoxides to afford polycarbonates.  The significantly lower activity of these manganese complexes has allowed for a detailed study of the polymer initiation process via FTIR.  Specifically, the nucleophilic ring-opening of a metal bound epoxide has been mechanistically evaluated in the presence  and absence of cocatalytic species such as DMAP and PPN⁺X^- salts.  Kinetic data and activation energies were determined for these ring-opening processes.  Where possible, X-ray structures of relevant manganese complexes will be presented in an effort to better understand the nature of the metal based intermediates afforded during the copolymerization process.