Preparation and characterization of cobalt-containing alcohols and diols

A series of cobalt-containing alcohols and diols were prepared and characterized. Intramolecular hydrogen-bonding was observed for the cobalt-containing diols Co₂(CO)₆(μ-η-(HO)R₁R₂CCCCR₁R₂(OH)] (1: R₁ = CH₃, R₂ = C₂H₅; 2: R₁ = CH₃, R₂ = C₃H₇), Co₂(CO)₆(μ-η-(HO)Ph₂CCCCPh₂(OH)] (3) and (μ-PPh₂CH₂PPh₂)Co₂(CO)₄(μ-η-(HO)Ph₂CCCCPh₂(OH)] (4). Potentially all the four compounds could serve as chelating O,O-ligands. In principle, it is possible for compounds (μ-PPh₂NHPPh₂)Co₂(CO)₄(μ-η-HCCCPh₂OH)] (5b), Co₂(CO)₆(μ-η-HCCC₂H₄OH] (6) and Co₂(CO)₆(μ-η-HCCC₃H₆OH)] (7) in their syn-conformations to behave as chelating O,N-ligands. To the best of our knowledge, compounds 5b, 6 and 7 are the first reported examples of PPh₂NHPPh₂-bridged dicobalt complexes.