ABSTRACT
This chapter focuses on experimental techniques to initiate reactions of different velocities. Manual mixing typically requires a few seconds before the first data point or sample can be taken, which is the dead time of the experiment. Single-mixing stopped flow instruments have two syringes that are moved simultaneously to mix two reactants. Double-mixing stopped flow instruments can realize more complex mixing schemes, such as pre-formation of a complex, followed by mixing of this complex with a third compound. This way, transient intermediates can be populated and their reactions with other compounds can be studied. In kinetic experiments, a reaction is typically started by manual or automated mixing of the components. A stopped flow instrument contains the reactants in two syringes that both connect to a mixing or reaction chamber. Quench flow experiments are used for reactions that cannot be followed by a spectroscopic signal in real time.
