Metal vapour synthesis of phospha-organometallic compounds via reaction of cobalt atoms with the phospha-alkyne tBuCP: synthesis and structural characterisation of the sandwich compounds [Co(η5-P3C2 tBu2)(η4-P2C2 tBu2)], [Co(η5-P2C3 tBu3)(η4-P2C2 tBu2)]

The reaction of cobalt atoms with tBuCP gives the sandwich compounds [Co(η5-P3C2 tBu2)(η4-P2C2 tBu2)] and [Co(η5-P2C3 tBu3)(η4-P2C2 tBu2)], which have both been structurally characterised by single crystal X-ray diffraction studies. The novel protonated tetraphospha-barrelene complex [Co(η4-P4C4 tBu4H)(η4-P2C2 tBu2)] is also formed in the reaction and has been structurally characterised as its [W(CO)5] adduct. Variable temperature NMR spectra of these complexes are reported and discussed.