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(n5-P3C2tBu2)(n4-P2C2tBu2)],[Co(n5 P2C3tBu3)(n4P2C2tBu2)] and the protonated tetraphospha-barrelene complex [Co(n4-P4C4 tBu4H)(n4-P2C2 tBu2)], the latter as its [W(CO)5] adduct

The reaction of cobalt atoms with tBuCP gives the sandwich compounds [Co(¿5-P3C2tBu 2)(¿4-P2C2tBu 2)] and [Co(¿5-P2C3tBu 3)(¿4-P2C2tBu 2)], which have both been structurally characterised by single crystal X-ray diffraction studies. The novel protonated tetraphospha-barrelene complex [Co(¿4-P4C4tBu 4H)(¿4-P2C2tBu 2)] 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.