Preparation of octahedral manganese(I) carbonyl complexes utilizing 1,1′-bis(diphenylphosphino)ferrocene (dppfe) and 1,1′-dimethylamino-2,2′-diphenylphosphinoethane (pn) as chelating ligands.: Crystal structure of the Mn-FBF3 complex, fac-(CO)3(dppfe)MnFBF3.