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The precise alignment of multiple layers of metal–organic framework (MOF) thin films, or MOF‐on‐MOF films, over macroscopic length scales is presented. The MOF‐on‐MOF films are fabricated by epitaxially matching the interface. The first MOF layer (Cu2(BPDC)2, BPDC=biphenyl‐4,4′‐dicarboxylate) is grown on an oriented Cu(OH)2 film by a "one‐pot" approach. Aligned second (Cu2(BDC)2, BDC=benzene 1,4‐dicarboxylate, or Cu2(BPYDC)2, BPYDC=2,2′‐bipyridine‐5,5′‐dicarboxylate) MOF layers can be deposited using liquid‐phase epitaxy. The co‐orientation of the MOF films is confirmed by X‐ray diffraction. Importantly, our strategy allows for the synthesis of aligned MOF films, for example, Cu2(BPYDC)2, that cannot be grown on a Cu(OH)2 surface. We show that aligned MOF films furnished with Ag nanoparticles show a unique anisotropic plasmon resonance. Our MOF‐on‐MOF approach expands the chemistry of heteroepitaxially oriented MOF films and provides a new toolbox for multifunctional porous coatings. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) coatings were prepared on gold electrodes through the conversion from Cu(OH)2 nanobelts to Cu3(BTC)2 MOFs (BTC = 1,3,5-benzenetricarboxylic acid). In the conversion from Cu(OH)2 to Cu3(BTC)2, the porosity and homogeneity of the coatings are tunable by controlling the EtOH : H2O volume ratio of the MOF precursor solution. The kinetics and mechanism of the conversion from metal hydroxide nanobelts to MOFs were investigated by using the quartz crystal microbalance (QCM) technique. The Cu3(BTC)2 coatings were finally tested for the size-selective electrochemical sensing and non-enzymatic electrocatalysis of glucose. [ABSTRACT FROM AUTHOR]

The degree of pore filling is an important parameter for defining guest@MOF properties in applications including electronics, optics, and gas separation. However, the interplay of key aspects of host–guest interactions, such as a quantitative description of the guest alignment or the structural integrity of the host as function of pore filling are yet to be determined. Polarisation‐dependent infrared spectroscopy in attenuated total reflection configuration combined with gas sorption allowed to simultaneously study the orientation of the guest molecule and structural changes of the MOF framework during the pore filling process. Thereby we found, that initially randomly oriented guest molecules align with increasing pore filling during adsorption from the gas phase. At the same time, the framework itself undergoes a reversible, guest molecule‐dependent rotation of the aromatic linker and a linker detachment process, which induce defects. [ABSTRACT FROM AUTHOR]