Cobalt (allyl) tris(carbonyl) Co[(η3-C3H5)(CO)3] was synthesized as potential MOCVD precursor, together with other allyl cobalt complexes of the type [(η3-C3H3R2)Co(CO)2L] (R=H or Me; L=CO, PEt3, TeEt2, iPrCN, tBuCN or CyCN (Cy=cyclohexyl)) . The vapour pressures of these complexes were measured by the Knudson effusion method, it was determined that room-temperature volatilities (0.1–4.0 Torr) of the allyl complexes [(η3-C3H5)Co(CO)3,], [(η3-C3H4Me)Co(CO)3], [(η3-C3H3Me2)Co(CO)3] and [(η3-C3H5)Co(CO)2(tBuCN)] were sufficient to achieve high concentrations in the vapour state needed for their application as cobalt MOCVD precrusors.
Vapour-phase thermal degradation (MOCVD) of seven complexes [(η3-C3H3R2)Co(CO)2L] in a stream of hydrogen at 180–250°C gave metal deposits, which were analysed by EDX and XPS.
The best MOCVD precursor proved to be unsubstituted cobalt (allyl) tris(carbonyl) [(η3-C3H5(Co(CO)3], which gave pure Co films after decomposition at 250°C. [[i]]
[i] Ron S. Dickson, Ping Yin, Mingzhe Ke, Julian Johnson, Glen B. Deacon, Polyhedron, Volume 15, Issue 13, July 1996, Pages 2237–2245. http://www.sciencedirect.com/science/article/pii/0277538795004807 . « The assessment of some cobalt and cobalt-tellurium complexes for MOCVD applications »