191719-65-0Relevant academic research and scientific papers
Structural characterization of several (CO)3(dppp)MnX derivatives, dppp = 1,3-bis(diphenylphosphino)propane and X = H, OTs, OC 2H5, Cl, Br, or N3. An assessment of their efficacy for catalyzing the coupling of carbon dioxide and epoxides
Darensbourg, Donald J.,Ganguly, Poulomi,Billodeaux, Damon R.
, p. 6025 - 6030 (2008/10/09)
The X-ray structures of a series of (CO)3(dppp)MnX complexes, X = H, OTs, OEt, Cl, Br, and N3, and dppp = 1,3-bis(diphenylphosphino)propane, prepared by literature methods are reported. Several of these derivatives have been examined for their ability to serve as catalysts for the coupling of cyclohexene oxide and carbon dioxide. Although, these organometallic complexes do catalyze the formation of polycarbonate, their activity is not competitive with other very effective catalysts for this coupling reaction. Nevertheless, findings from these studies contribute significantly to our understanding of this important process. The complex containing the alkoxide ligand is the most active, yet it possesses a TON (mol epoxide consumed/mol Mn) of only 50 for a 24 h reaction. In this instance the (CO)3(dppp)MnOEt complex exists as the carbonate species, (CO) 3(dppp)MnOC(O)OEt, because of rapid CO2 insertion into the Mn-OEt bond. The order of epoxide ring-opening by the X group (initiator) was found to be -OC(O)OR > Cl ≥ N3 > Br. Furthermore, since these complexes are substitutionally inert, this process is best defined as occurring via an associative interchange process and is rate-limiting.
Preparation, reactions, and infrared spectra of fac-(CO) 3(P-P) Mn-Z complexes (P-P = DEPE, DPPE, DPPP; Z = H, OTs, OMe, OC(O) OMe, NCO, C1, Br, N3)
Li, Guang Qing,Orchin, Milton
, p. 43 - 47 (2007/10/03)
A series of new octahedral Mn(I) complexes fac(CO)3(depe)Mn-Z (depe = 1,2-bis(diethylphosphino)ethane, Z = H, OTs, OMe, OC(O)OMe, NCO, Cl, Br, N3) have been prepared and characterized, particularly with respect to their infrared spectra. The variations observed in the carbonyl stretching frequencies associated with the coordinated carbon monoxides are a function of the Z groups. Comparison of these spectra with similar spectra of the analogous dppp, 1,3-bis(diphenylphosphino)propane and dppe, 1,2-bis(diphenylphosphino)ethane complexes shows the effect of substituting phenyl groups for ethyl groups on the phosphorus atom. The depe azido complex (Z = N3) reacts with alkynes to give a triazolato complex which on hydrolysis with HCl liberates the triazole and regenerates the chloro complex from which the azido complex is made.
