Compositional control of pore geometry in multivariate metal-organic frameworks: an experimental and computational...

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) offer tunable porous structures.
• Controlling MOF pore geometry is crucial for applications like gas storage and catalysis.
• The DMOF-1 structure ([Zn2(bdc)2(dabco)]) serves as a base for creating multivariate MOFs.

Purpose of the Study:

• To investigate a doping procedure for tailoring pore geometry in multivariate MOFs.
• To explore the relationship between linker ratios, pore geometry, and framework properties.
• To demonstrate the potential for controlled modification of MOF pore characteristics.

Main Methods:

• Synthesis of five series of multivariate MOFs using a doping approach with varying linker ratios.
• Characterization of MOF structures and pore geometries.
• Computational analysis to understand the factors influencing pore size and shape.

Main Results:

• Series 1-3 showed a transition from square to rhomboidal pores with increasing 2-substituted bdc linker proportion, with some exhibiting temperature-dependent phase changes.
• Series 4 and 5 displayed uniform pore geometries (square and rhomboidal, respectively).
• Computational studies indicated that non-covalent interactions between linkers, controlled by ligand functionality and ratio, dictate pore size and shape in series 1 and 2.

Conclusions:

• A facile doping method allows for the precise tailoring of pore geometry in MOFs.
• Ligand functionality and ratio are key parameters for controlling pore size and shape through non-covalent interactions.
• This approach provides a versatile strategy for designing MOFs with specific pore characteristics for targeted applications.