Aspects of the flame chemistry of cobalt

Abstract

Photometric measurements of line and band emissions from hydrogen + oxygen + nitrogen flames to which small quantities (≈ 1 part in 10⁶) of cobalt are added in the form of cyclopentadienylcobalt dicarbonyl vapour show that free atoms are the main cobalt containing species present. Lesser amounts of CoO and Co(OH)₂ are also formed. Thermochemical parameters governing formation of CoO are determined. Catalysis of flame free radical recombination resulting from addition of cobalt at higher concentrations (≈ 1 part in 10⁴) is observed. This catalysis is quantitatively interpreted in terms of a suggested cyclic gas phase mechanism in which Co, CoO, CoOH and Co(OH)₂ all participate.