Reticular framework materials as versatile platforms for controllable polymer synthesis

Polymers play a crucial role in a wide range of applications, and achieving precise control over their primary structures (e.g., molecular weight, tacticity) and higher-order architectures (e.g., cross-linking density, macroscopic morphology) remains a significant challenge in modern materials science. Traditional polymerization methods often fall short in achieving the necessary structural precision, limiting the development of advanced functional polymers. The emergence of reticular framework materials, such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs), offers promising solutions to these limitations. This Review systematically examines the unique properties of these materials, with a focus on their molecularly tunable pore architectures and compositions, which provide versatile platforms for controlled polymer synthesis. These materials enable three primary strategies: (1) serving as confined nanoreactors to spatially regulate polymer growth, (2) offering tailored reaction sites for controlling polymer network morphology, and (3) acting as heterogeneous catalysts to enhance the efficiency and uniformity of linear polymer production. For each strategy, we delve into the underlying polymerization mechanisms and present illustrative examples that demonstrate key design principles. These advancements have led to the development of novel polymer materials with superior properties compared to those synthesized through conventional methods, driving innovation in fields such as energy storage, biomedicine, and environmental remediation. Finally, we discuss future research directions and key challenges, including the need to improve controlled polymerization in terms of regioselectivity, stereoregularity, molecular weight distribution, and sequence control, while also advancing strategies to program macroscopic polymer morphologies. We anticipate that ongoing progress in the functionalization and fabrication of reticular framework materials will enable synthetic precision comparable to that of biological systems, unlocking unprecedented control over polymer design and performance.