Reaction mechanism and kinetics of aqueous solutions of primary and secondary alkanolamines and carbon dioxide

The mechanism and kinetics of the reaction between aqueous solutions of CO a and the alkanolamines 1-amino-2-propanol, 3-amino-1-propanol,2-methyl ami noethanol and a-ethyl aminoethanol were investigated using a stopped flow t echnique. It was found that the reaction orders according to power law kine tics were between 1.1 and 2.0, depending on the alkanolamine and the concen tration ranges investigated. This fractional order was therefore considered to be further evidence that carbamate formation takes place according to a zwitterion mechanism rather than a one-step reaction. The kinetic rate par ameters for these alkanolamines were evaluated from experimental data at 30 3 K according to this mechanism.