Keto–Enol Equilibrium from NMR Data: A Closer Look at the Laboratory Experiment

Experimental setup and evaluation of equilibrium and kinetic data on the keto–enol transformation in acetylacetone and similar β-diketones has been discussed in relation to a physicochemical laboratory NMR experiment. The slow kinetics of this transformation requires prolonged NMR measurements that can be organized in two ways: either keeping several samples in thermostats (minimizing the instrument's time) or employing the temperature jump technique (providing for the estimation of both equilibrium and kinetic parameters). By analyzing the data students learn how to apply linear and nonlinear regression as well as how to interpret results employing quantum chemical calculations.