Staggered pillaring: a strategy to control layer-layer packing and enhance porosity in MOFs

• Published in: Journal of coordination chemistry Vol. 69; no. 11-13; pp. 1802 - 1811
• Main Authors: Linder-Patton, Oliver M., Doonan, Christian J., Sumby, Christopher J.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02.07.2016; Taylor & Francis Ltd
• Subjects: Alignment; DABCO; Joints; Ligands; Metal-organic frameworks; pillaring; Porosity; pyrazine; Pyrazines; Strategy; Surface area
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2016.1168521

Convenient access to metal-organic frameworks (MOFs) with defined structural and chemical features is required to satisfy the design criteria for targeted applications. Here, we demonstrate that staggered pillaring between the layers of a binodal 2-D metal-organic framework (MOF) at only the alternating axial sites of the dimetallic copper(II) paddlewheel nodes aligns the 2-D layers and significantly increases the porosity of the resulting 3-D MOF. Two new pillared MOFs of this form were synthesized, [Cu 3 (bcppm) 2 (NO 3 ) 2 (L)]·xS (where bcppm = bis(4-(4-carboxyphenyl)-1H-pyrazolyl)methane and L = DABCO and pyrazine), via a mixed ligand synthesis. Both pillared 3-D frameworks have considerably larger BET surface areas than their 2-D counterpart, due to the alignment of 2-D layers from a staggered to eclipsed arrangement in the 3-D material; this increase in pore space and surface area is realized despite both materials being 2-fold interpenetrated. The strategy outlined here demonstrates a method of designing porous 3-D MOFs from nonporous 2-D-layered materials with a minimum of layer-layer connections.