Cobalt hydride-tetracarbonyl CoH(CO)4: pale yellow liquid or crystals, mp.-26°C, dec. -20°C, strong acid (pKs = 1, comparable to HNO3, good catalyst (f.e. hydroformylation). It is synthesized by hydrogenation of dicobalt octacarbonyl.: Co2(CO)8 + H2 → 2 CoH(CO)4
Due to low decomposition temperature, CoH(CO)4 is not convenient as CVD precursor.
Nevertherless, CoH(CO)4 was reported to be used as precursor for the growth of thin films of metallic cobalt Co in the pores of porous silicon layers, by using Chemical Vapour Infiltration and Decomposition (CVID) technique.[[i]]
[i]B.J. Aylett, L.G. Earwaker, J.M. Keen, MRS Proceedings/Volume 282/1992, DOI: http://dx.doi.org/10.1557/PROC-282-281, “Metallisation and Silicidation of Porous Silicon”