Metal–organic frameworks (MOFs) have attracted great interest due to their potential applications such as catalysis, gas storage, and separation of molecules. Organic linkers bearing imidazolium functional group have been emerged as a building unit for constructing several MOFs. However, there is a little study on the utilization of imidazolium functionality in MOFs for various applications. In this research, we designed a new imidazolium ligand with pyrazolate as a metal binding sites and synthesized cobalt based 3D MOF from the ligand. The potential applications of the MOF (JCM-1) have been studied. In this presentation, 1) hydrocarbon separation, 2) ammonia capture and 3) proton conduction applications will be introduced.