Promoting photoswitching in mismatching mixed-linker multivariate Zr₆ MOFs

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Multivariate metal-organic frameworks (MTV MOFs) offer enhanced properties by combining different components.
• Tailoring electronic properties via structural defects in MTV MOFs is challenging due to limited examples and electronic structure data.

Purpose of the Study:

• To develop a novel approach for creating photoswitching MTV MOFs with tunable electronic properties.
• To investigate the impact of structural defects and mixed-linker composition on MOF characteristics.

Main Methods:

• Utilized a multivariate mismatching linker strategy with biphenyl and azobenzene ditopic linkers.
• Generated nanoparticulated MOFs with controlled lattice parameters and porosity.
• Investigated structural defects, including dangling linkers, and their effect on electronic structure.
• Employed first-principles calculations to support experimental findings.

Main Results:

• Successfully generated photoswitching MTV MOFs with variable lattice parameters and porosity.
• Introduced structural defects, such as dangling linkers, by mismatching crystal lattices.
• Demonstrated tunable electronic structures and a significant bandgap reduction upon incorporating azobenzene linkers.
• Observed constrained cis-trans photoswitching of azobenzene linkers.

Conclusions:

• The multivariate mismatching linker approach enables the creation of photo-responsive MOFs.
• Structural defects and linker composition effectively tune the electronic properties, particularly the bandgap.
• These findings open avenues for developing novel photo-switching materials.