Abstract: The present invention relates to metal-organic frameworks and, in particular, a continuous flow process for synthesising a metal-organic framework comprising the steps of: providing a ligand and a metal salt which are suitable for forming a metal-organic framework, mixing the ligand and metal salt with a solvent to form a mixture, and providing the mixture at a temperature sufficient to cause the ligand and the metal salt to react to form a metal-organic framework. The invention also relates to a method for the treatment of a metal-organic framework to extract unreacted ligand from the metal organic framework, a method for synthesising a metal-organic framework using recycled unreacted ligand, and uses for metal-organic frameworks.