The compounds [RCCo₃(CO)₉](R = F, CHF₂, CF₃, or C₂F₅) have been obtained in yields of 15–70% from reaction between the fluoroalkyltetracarbonylcobalt derivatives [(RCF₂)Co(CO)₄] and either sodium tetracarbonylcobaltate(–1), or octacarbonyldicobalt in the presence of donor solvents, such as tetrahydrofuran or ether. Reaction of Na[Co(CO)₄] with [{(CO)₄Co(CF₂)}₂] similarly gives [{(CO)₉Co₃C}₂] in ca. 16% yield. Evidence is presented that the reaction of ClCO·(CF₂)₂·COCl or ClCO(CF₂)₃·COCl with an excess of Na[Co(CO)₄] gives the compounds [(CO)₉Co₃C(CF₂·CO₂H)] and [(CO)₉Co₃C(CF₂·CF₂·CO₂H)] respectively as major reaction products, in addition to the expected products [(CO)₄Co(CF₂)₂Co(CO)₄] and [(CO)₄Co(CF₂)₃Co(CO)₄]. Attempts to extend the reactions of [(CF₃)Co(CO)₄] or [(n-C₃F₇)Co(CO)₄] to other carbonylmetal anions were unsuccessful, as was the attempted reaction of [(CF₃Co(CO)₃(PPh₃)] with Na[Co(CO)₄]. The preparation of [(CF₃)₂CF–Co(CO)₄] is described, and its reaction with Na[Co(CO)₄] has been shown to give a low yield of a product tentatively identified as [(CO)₃Co(CO){C(CF₃)₂}Co(CO)₃]. In the light of these findings possible mechanisms for the reaction are discussed.