One-Step Synthesis of 2,5-Bis(chloromethyl)-1,4-dioxane from Epichlorohydrin Using ZIF-8, Taking Advantage of Structural Defects

We demonstrate herein the ZIF-8-only-mediated catalysis of the cyclodimerization of epichlorohydrin to 2,5-bis(chloromethyl)-1,4-dioxane in the absence of co-catalyst and solvent. The easy handling and economic aspects of ZIF-8, in addition to the one-step reaction to produce the cyclodimer, make this catalyst attractive even for industry. It has been clearly illustrated that the nature of the method used to synthesize ZIF-8 affected the yields of the cyclodimers. Specifically, the method employed to produce ZIF-8 directly influences the amount of crystal structural defects, which in turn impacts their performance as catalysts. To emphasize the role of defects, other physical properties, such as surface area and particle size, were controlled during the synthesis of the ZIF-8 catalysts. Remarkably, the amount of structural defects was quantified by temperature program desorption analysis. Graphical A straightforward one-step cyclodimerization of epichlorohydrin using ZIF-8 as catalyst in the absence of solvent or co-catalyst is reported for the first time. It is shown that the nature of the method used to synthesize ZIF-8 strongly affects the yield of the cyclodimeric product. The acidic and basic properties of the ZIF-8 samples were determined by temperature program desorption analysis.