Magnetic Cores with Porous Coatings: Growth of Metal‐Organic Frameworks on Particles Using Liquid Phase Epitaxy

A novel method for the homogeneous coating of magnetic nanoparticles with metal organic frameworks (MOFs) is reported. Using a liquid phase epitaxy process, a well‐defined number of [Cu₃(btc)₂]nH₂O, HKUST‐1, layers are grown on COOH terminated silica magnetic beads. The structure and porosity of the deposited MOF coatings are studied using X‐ray diffraction and BET analysis. In addition, size and shape of the fabricated composites are analyzed by transmission electron microscopy. Potential applications of particle based MOF films include catalytic coatings and chromatographic media.     

Multi Variant Surface Mounted Metal–Organic Frameworks

Hybrid surface mounted metal–organic frameworks (h‐SURMOFs) of multi variant core‐shell (cs) and core–shell–shell (css) structures (SURMOF A ‐ B and A ‐ B ‐ C , A : [Cu₂(bdc)₂(dabco)]; B : [Cu₂(NH₂‐bdc)₂(dabco)]; C : [Cu₂(ndc)₂(dabco)], bdc = 1,4‐benzenedicarboxylate; NH₂‐bdc = 2‐amino‐1,4‐benzenedicarboxylate; ndc = 1,4‐naphtalenedicarboxylate; dabco = 1,4‐diazabicyclo[2.2.2]octane) with specific crystallographic [001] orientation and incorporated amino groups at a controllable depth within the bulk are deposited via liquid phase epitaxial (LPE) approach on pyridyl‐terminated self‐assembled monolayers (SAM). The location of the (amino) functionality can be precisely controlled through tuning the thickness (number of deposition cycles) of each sub‐multilayer block according to the LPE deposition protocol. The chemo‐selective and location‐specific post deposition (chemical) modification of the amino groups in the cs and css‐type h‐SURMOF samples is achieved. The h‐SURMOFs allow one to probe functional groups at certain location in the volume of hybrid MOF crystallites attached to surfaces as thin film coatings. Multiplex adsorption kinetics of FPI (FPI = 4‐fluorophenyl isothiocyanate) is observed in h‐SURMOFs due to their multi‐variant pore structures in samples of A‐B and A‐B‐C . Conceptually, the stepwise LPE growth method enables fabrication of hybrid SURMOFs and incorporation of multi‐variant functionalities into one homogeneous thin film material, providing precisely tunable pore environment for selective adsorption, separation, etc.