Which step comes directly after heating the reaction mixture to reflux?

After heating the reaction mixture to reflux, the next logical step is to separate the reaction mixture with deionized (DI) water. Refluxing allows the reaction to proceed at an elevated temperature while preventing loss of solvents or reactants, typically resulting in the formation of products. Once the reaction has completed after a designated time, quenching the reaction by adding DI water is often necessary to halt the reaction process and provide an aqueous phase for later separation of organic and aqueous layers.

This step is crucial because it also helps to dissolve any unreacted reagents and soluble byproducts, making the subsequent isolation of your desired product more efficient. The separation often includes specific techniques such as extraction, which can yield a purer final product.

The other choices do not logically follow the reflux phase as they either pertain to preparation or analysis steps that are performed later in the process. Clamping the flask or preparing the mixture would ideally happen before the reaction is heated, while collecting IR spectra usually occurs once the product is isolated and purified. Thus, separating the reaction mixture with DI water appropriately follows the completion of the reflux process.