MOF Decomposition and Introduction of Repairable Defects Using a Photodegradable Strut

Abstract

Photoswitchable componentsc an modulate the properties of metal organic frameworks (MOFs);h owever, photolabileb uilding blocks remain underexplored. An ew strut NPDAC (2-nitro-1,4-phenylenediacetic acid) that undergoes photodecarboxylation has been prepared and incorporated into aM OF,u sing post-synthetic linker exchange (PSLE) from the structural analogue containing PDAC (p-phenylenediacetic acid). Irradiationo fN PDAC-MOF leads to MOF decompositiona nd concomitantf ormation of amorphous material. In addition to complete linker exchange, MOFs con-taining am ixture of PDAC and NPDAC can be obtained throughp artial linker exchange. In NPDAC30-MOF,w hich containsa pproximately 30 %N PDAC, the MOF retains crystallinitya fter irradiation, but the MOF contains defect sites consistentw ith loss of decarboxylated NPDAC linkers. The defect sites can be repaired by exposure to additional PDAC or NPDAC linkers at am uch faster rate than the initial exchange process. The photoremoval and replacement process may lead to am ore general approach to customizable MOF structures.[a] Dr.

Pressure-Induced Postsynthetic Cluster Anion Substitution in a MIL-53 Topology Scandium Metal-Organic Framework

“…[12][13][14] Dynamic SBU solvent substitution can facilitate structural flexibility 15,16 and metal-ion exchange, 17,18 while also offering routes to pore functionalisation through linker exchange, [18][19][20][21][22] linker incorporation/grafting, [23][24][25][26] and defect substitution. [27][28][29][30][31][32][33] Coordinative exchange reactions may also be responsible for MOF degradation, for example through hydrolysis. 34 To date, most studies on such reactions within MOFs focus on either binding and removal of neutral solvent molecules, 35 or direct exchange of carboxylate and/or pyridyl-based ligands, despite the fact that a significant number of commonly observed SBUs contain bridging oxo or hydroxo ligands.…”