Kinetics and equilibrium of Co 2(CO) 6(η 4-norbornadiene) formation from Co 2(CO) 8 and norbornadiene under CO

Abstract

The formation of Co 2(CO) 6(η 4-NBD) from Co 2(CO) 8 and NBD is a reversible endothermic reaction: Co 2(CO) 8 + NBD ▪ Co 2(CO) 6(η 4-NBD) + 2CO; Δ H 0 14.9 ± 0.7 kcal mol −1 In the forward reaction the carbon monoxide evolution is of first order in both Co 2(CO) 8 and NBD and of minus first order in CO. The carbon monoxide uptake in the reverse reaction is first order in both Co 2(CO) 6(η 4-NBD) and CO. The temperature dependence of the equilibrium constant K, and of the rate constant for the forward reaction k CO between 25 and 45°C is represented by log 10 K = (7.41 ± 0.48) − (3259 ± 147)/ T ( K in M) and log 10 k CO = (18.30 ± 1.75) − (7054 ± 540)/ T ( k CO in s −1).