No abstract

Whereas the preparation of defined metal–organic framework (MOF) materials via hydrothermal or diffusion methods typically requires hours to days, our simple precipitation route opens the access to the well‐known HKUST‐1 frameworks within minutes. Crucial for the formation of a well‐defined, crystalline material is the choice of suitable precipitating solvents, with methanol and ethanol being the most favorable ones. This approach could be extended to the formation of dense, surface‐mounted MOF films (so‐called SURMOFs), in particular if the surfaces are decorated with suitable binding groups by formation of self‐assembled monolayers (SAMs). By combination with micro‐contact printing (μCP), patterned SURMOFs became accessible, in which the precipitating solvent is decisive on the formation of either spatially restricted films or single particles.

Flexible in many aspects: inkjet printing of metal-organic frameworks permits their larger area, high-resolution deposition in any desired pattern, even in the form of gradients or shades. When flexible substrates are used, many applications can be envisioned, such as sensing and capture of hazardous gases for personal safety measures.

Multivariate metal−organic frameworks (MTV-MOFs) incorporating multiple chemical functionalities within single-phase crystalline materials show superior properties that arise from synergistic effects. Herein, we report an efficient and versatile method for the growth of highly oriented multivariate surface-attached MOFs (MTV-SURMOFs) by the combination of the liquid-epitaxial growth method (LPE) and the mixed-linker strategy. Twenty-six MTV-SURMOFs of the [M 2 L 2 P] type with a maximum of five different dicarboxylate linkers (L) were deposited onto suitably functionalized surfaces. Systematic studies by infrared reflection absorption (IRRA) spectroscopy and surface XRD provide evidence for the formation of highly oriented MTV-SURMOFs. Interestingly, the pK a 's of the dicarboxylate linkers play a crucial role for the orientational quality of the MTV-SURMOFs. In addition, benzene uptake experiments showed that the MTV-SURMOFs exhibit up to 2.6 times higher adsorption capacity as compared to the single-linker SURMOFs, demonstrating the synergistic effects in these surface systems.