Reciprocal regulation between MOFs and polymers

• The reciprocally regulated relationship between the metal–organic frameworks (MOFs) and polymers is reviewed. • The designed nanospace of the MOF pore has an impact on polymerization control and polymer recognition. • The polymers contribute to the stability and controlled phase transitions of the MOFs. • The encapsulated polymers in MOFs show new functions on the polymers themselves and/or the MOFs. The development of MOF–polymer hybrid materials has contributed to both fields of science in coordination chemistry and polymer chemistry. MOFs composed of metal ions and organic ligands are crystalline materials possessing nanopores with defined size and surface functionality. Various efforts have been placed regarding polymer synthesis, recognition, and separation in MOF pores. Polymers are chain molecules with flexible conformations. The unique properties of the polymer chains influences MOFs in multiple ways, such as controlled crystal growth, stabilization, and functionalization. This review discusses the mutual contributions of MOFs and polymers, in hybrid systems. Understanding their reciprocally enhanced relationships provides new insights for further development of MOF-polymer composites.