Simultaneous high throughput assessment of thermodynamic and kinetic behaviour of chemical reactions: theory and experiment

Abstract

There is an increasing requirement in the pharmaceutical industry to rapidly monitor reactions. High throughput screening (HTS) is typically achieved by performing experiments simultaneously in array format in microtitre plates. One method of monitoring reactions that has received particular attention recently is the use of thermal measurements. The change in temperature with time resulting from a reaction depends on both thermodynamics and kinetics. Temperature can be monitored in a number of ways, one of which suitable for HTS is thermographic imaging. Relating such thermal information to reaction parameters such as enthalpy and rate is complicated by issues such as heat loss to the surroundings and heat transfer to different parts of the apparatus. A method is presented whereby information obtained from thermal imaging of microtitre plates can be used, along with experimental data for heat transfer to the surroundings and the microtitre plate, to rank reaction enthalpy and time to completion of a set of reactions. Finally a comparison to enthalpies obtained by microcalorimetry is made.