The ligand 4,4′-(1,2,4,5-tetrazine-3,6-diyl)dibenzoic acid has been designed and explored with the aim of using it as a linker to construct three-dimensional metal–organic frameworks (MOFs). We have been successful in the formation of a potassium 3D-MOF using this novel linker. This compound has a three-dimensional structure, wherein the layers formed by potassium ions and carboxylate groups are separated by this organic ligand. Luminescence and cytotoxicity studies have been performed. We used molecular simulations to predict the porous properties of an isoreticular compared to IRMOF-16 based on this linker due to the similarity of the newly designed ligand with p-terphenyl-4,4′′-dicarboxylate present in IRMOF-16.