Gases and pollutants can be filtered from air and liquids by means of porous, crystalline materials, such as metal-organic frameworks (MOFs). To further partition these pores and enhance their sorption capacity, a team of scientists have developed a fast and versatile two-in-one synthetic strategy, combining metal coordination with the covalent chemistry of light elements. The new pore-space-partitioned material could be used as a highly efficient adsorbent of ammonia.