ORGANO-EARTH METAL-COMPLEXES OF D-BLOCK ELEMENTS .4. SINGLE-POT SYNTHESIS OF VOLATILE ORGANOGALLIOCOBALT COMPLEXES, MOLECULAR-STRUCTURE OF (MU-[3-(DIETHYLAMINO)PROPYL]GALLIO)[BIS(TETRACARBONYLCOBALT)]

Carefully purified starting materials and precisely controlled stoichiometries guarantee high yield "one pot synthesis" of the novel volatile organogalliocobalt complexes 2-7. These compounds are stabilized by intramolecular adduct formation at the gallium center. Synthesized compounds are identified by H-1, C-13, P-31-NMR, infrared nu(CO) and MS data. A single crystal X-ray analysis of (mu-[3-(diethylamino)propyl]gallio)[bis(tetracarbonylcobalt)] reveals cobalt gallium bond distances averaging to 254.3 pm. Thermal decarbonylation of 2-4 in the presence of phosphines, e.g. P(C6H5)3, yields quantitatively the trans-phosphine substituted complexes 5-7. In polar solvents those latter compounds exhibit a significantly weakened tendency towards heterolytic dissociation of the metal-metal bond. This behavior reflects a strengthened cobalt-gallium interaction, as it is also indicated by mass spectroscopy.