Understand the reaction kinetics and the rate equation to help optimisation

20 February 2004

The reaction rate equation will tell you the reaction order for each of the various components and lead to a better understanding of the reaction mechanism. This, in turn, should aid in modifying the reaction conditions to optimise the yield. In some cases it may show that you are very unlikely to be able to force the reaction to completion because of the reaction order. So for example, a reaction, which is second order in one component, will show a marked reduction in reaction rate as the concentration of that component decreases. As a result excessively long reaction times may be required to push the reaction to completion. Don't forget that the solvent may also be part of the reaction rate equation, particularly if solvation is critical to the success of the reaction (e.g. in alkyl lithium and LDA mediated processes, for further details see D.B. Collum et al JACS, 2000, 122, 2452).