Utilising hinged ligands in MOF synthesis: a covalent linking strategy for forming 3D MOFs

作者：Coghlan Campbell J^*; Sumby Christopher J; Doonan Christian J

来源：CrystEngComm, 2014, 16(28): 6364-6371.

DOI：10.1039/c4ce00181h

Here we show that connecting two equivalents of a bis-pyrazolymethane `hinged' link by a carbon-carbon bond characteristically `extends' the 2D layered metal-organic frameworks (MOFs) typically formed with such compounds into 3D MOF materials. 1,1,2,2-Tetrakis[4-(4-carboxyphenyl)-1H-pyrazol-1-yl] ethane (L) was prepared in three steps and upon reaction with late transition metals, namely copper(II), cadmium( II) and zinc( II), gave 3D MOFs [Cu-2(L)(H2O)(2)] 1.4DMF and [M2L]center dot xDMF (M = Zn, x = 1; M= Cd, x = 1.75). The 3D MOFs display gating behaviour in their adsorption isotherms, consistent with 3rd generation flexible structures. Furthermore, the 3D MOFs showed appreciable affinity for CO2 at 293 K however, due to the larger pore sizes, molecular sieving of CO2/N-2 was not observed. Reaction of L with cobalt( II) gave a 3D hydrogenbonded network incorporating 1D coordination polymer chains that is topologically equivalent to the Zn and Cd MOFs. The strategy outlined here demonstrates a novel route for designing more chemically and thermally robust 3D MOFs from 2D layered materials.

• 出版日期2014