Unravel Rapid Reaction Kinetics with Advanced Spectroscopic Techniques

Chemical kinetics, the study of the rates and mechanisms of reactions, is an indispensable tool in both chemical discipline development and scientific research. With it, researchers can tell whether a reaction can occur, how fast it will happen, and how to control the speed.

With applications in both basic and applied sciences, chemical kinetics lets us measure how fast reactants are consumed and products are formed-with that information, we can optimize chemical processes, determine reaction times, and completion. This helps us understand the interplay between metabolic processes, absorption and interaction of drug substances (pharmacokinetics), or industrial synthesis of fine and bulk chemicals used in various applications including consumer products and food and beverages.

In industrial settings, chemical kinetics data can help increase the production of chemical products or slow down the reaction rate or side reactions to reduce the consumption of raw materials, reduce the burden of separation operations, and eventually improve the product quality.

However, the timescales of these processes vary by many orders of magnitude. Nuclear transformations and geological processes are some of the slowest while reactions such as the precipitation of a salt or neutralization of an acid occur in less than 0.1 seconds. The differences in time can be attributed to several factors such as the chemical nature of the reacting substances, the physical state of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst.

Spectroscopic techniques, especially infrared (IR) spectroscopy, can give specific chemical information during a reaction and modern FT-IR (Fourier transform infrared) spectrometers have fast scan capabilities allowing for fast chemical reactions to be monitored in real time.

Stopped-flow instruments are one of the most frequently used in rapid kinetics. Small volumes of solutions are rapidly driven from syringes into a high efficiency mixer to initiate a fast reaction. The reactions are typically monitored simply using UV-visible absorbance or fluorescence. These techniques are useful for monitoring reaction progress. However, they don’t produce useful information about the chemistry of the reaction and the identities of the species present.

However, the coupling of an FT-IR spectrometer with a stopped-flow system generates significant spectral and chemical information while retaining the speed of the chemical reaction.

Learn more about how fast scan speeds up to 100 scans/sec in an FT-IR instrument can help unravel fast reactions and lead to deeper insights: