Topological Characterization of Metal-Organic Frameworks: A Perspective

Area of Science:

• Materials Science
• Crystallography
• Computational Chemistry

Background:

• Metal-organic frameworks (MOFs) have rapidly expanded, with over 120,000 structures in the Cambridge Structural Database.
• Topological analysis simplifies complex MOF structures, revealing underlying connectivity crucial for material design and synthesis.
• While common MOF topologies are easily identified, complex structures with diverse building blocks pose significant characterization challenges.

Purpose of the Study:

• To highlight the importance of topological analysis in the field of MOFs.
• To review existing software tools for MOF topology assignment.
• To discuss the methods, limitations, and community adoption of these computational tools.

Main Methods:

• Discussion of topological analysis principles in MOF chemistry.
• Review of software packages like ToposPro, MOFid, and CrystalNets for MOF structure simplification and topology assignment.
• Analysis of node and linker definition challenges in complex MOF architectures.

Main Results:

• Established MOF topologies (e.g., fcu, sql, dia) are readily assigned.
• Complex MOFs present difficulties in defining nodes and linkers, leading to ambiguous topological representations.
• Software tools utilize simplification and matching algorithms to assign topology descriptors to MOF structures.

Conclusions:

• Topological analysis is indispensable for advancing MOF research and development.
• Current software tools offer valuable assistance but have limitations, particularly for intricate MOF structures.
• Understanding and addressing these limitations is key to broader adoption and improved MOF design.