Phase behaviour of the catalyst dicarbonyl(η5-cyclopentadienyl)-cobalt in carbon dioxide

The phase behaviour of the binary mixture of carbon dioxide and the cobalt complex dicarbonyl(η5-cyclopentadienyl)-cobalt, CpCo(CO)2, has been investigated. This organometallic compound is one of the most effective catalysts of cyclotrimerization reactions of arylisocyanates and alkynes. Vapour–liquid equilibrium (VLE) measurements were undertaken in a static analytical apparatus at 313.15, 323.15 and 363.15 K at pressures up to 15 MPa. p, T isopleths were measured by a synthetic method in a Cailletet apparatus. Nine different compositions ranging from 17.56 to 94.23 mol% of CO2 were measured up to 15 MPa. Modelling with the Peng–Robinson equation of state (PR EOS) gave reasonable results in the correlation of the experimental phase equilibrium compositions using two temperature-dependent interaction parameters.