Münster University chemists create new types of Lewis acids

Researchers at the University of Münster have developed a method which makes it possible to create three-coordinate Lewis superacids on the basis of phosphorus. Previously, it had not been possible to isolate this type of compound, either in a liquid or in a solid state, due to its extreme electrophilicity and the associated reactivity. In chemistry, Lewis acids are compounds which endeavour to accept electron pairs. Because of this so-called electrophilicity, they are often used to speed up chemical reactions. One example of this is the production of polyurethane synthetics used in the manufacture of foams for building insulation, car seats and household sponges. "We use special substituents which regulate the electrophilicity of the phosphorus atom," says Dr. Fabian Dielmann, who heads an Emmy Noether Junior Researchers Group at Münster University. "As a result, the reactivity of the compounds can be reduced somewhat, enabling them to be isolated as crystalline solids.