New ‘chain mail’ material of interlocking molecules is tough, flexible and easy to make

Catenanes — materials made of interlocking molecules, similar to medieval chain mail — have proved laborious to make since their discovery 25 years ago. Now, chemists have found a way to make unlimited quantities of catenanes in one single chemical step. Using reticular chemistry, they modified covalent organic frameworks to create a 3D network that is flexible and tough. These catena-COFs could prove useful wherever flexibility and resilience are needed — in armor, airplanes or clothing.