Synthesis and characterization of a decacobalt carbonyl cluster with two semi-interstitial phosphorus atoms

The synthesis and characteristic properties of decacobalt carbonyl cluster, containing two partially-encapsulated phosphorus atoms, were analyzed. The [Co₁₀P₂(CO)₂₃H]^2- cluster exhibits a core structure in which each of the two phosphorus centers is coordinated by seven cobalt atoms, four of which comprise an intervening square. The semi-interstitial nature of phosphorus centers suggests the possibility of adding four more cobalt atoms to generate a peanut-like cluster, in which two monocapped square antiprisms are fused through a square face. The results show that greater cobalt cluster nuclearities can be achieved, leading to higher-spin molecules.