Opening Metal-Organic Frameworks Vol. 2: Inserting Longer Pillars into Pillared-Paddlewheel Structures through Solvent-Assisted Linker Exchange

Solvent-assisted linker exchange (SALE) was performed on a pillared-paddlewheel metal organic framework (MOP), SALEM-5, to achieve incorporation of longer linkers into the material. The 9-A meso-1,2-di(4-pyridy1)-1,2-ethanediol pillar of SALEM-5 was successfully replaced by 11A, 14-angstrom, and I7-A pillars to generate daughter MOFs SALEM6, SALEM-7, and SALEM-8. The daughter frameworks possess more open cages, as was demonstrated by structural modeling from the powder X-ray diffraction patterns, and larger solvent accessible space, as was demonstrated by thennogravimetric analysis. Finally, a study was performed to (as an indicator of the Zn-L bond strength) on the outcome examine the effect of pK(a) of monoprotonated dipyridyl pillars of SALE.