ON THE REACTION OF SODIUM TETRACARBONYLCO BALTATE WITH ALUMINIUMTRICHLORID - MOLECULAR-STRUCTURE OF CO-4(CO)(13)AL(THF)(3)CO-3(CO)(10)

The reaction of NaCo(CO)(4) with AlCl3 in benzene has been studied. Ma in product of the reaction is Co-4(CO)(12). However, fractional crysta llization of the crude reaction mixture gives small amounts of black c rystals of the cobalt cluster Co-4(CO)(13)Al(THF)(3)Co-3(CO)(10). A si ngle crystal structure determination has revealed a quasi-octahedrally coordinated Al atom which is bridging a Co-3(CO)(9)-oxymethylidin-tri cobalt-nonacarbonyl cluster unit and a Co-4-carbonyl cluster unit. Thr ee THF ligands are completing the octahedral environment of the group- III metal. The aluminium atom is bonded to the oxygen atoms of three m u 3-bridging CO groups of the Co-3- and Co-4-cluster fragments.