No abstract

Metal-organic frameworks (MOFs) enable the design of host-guest systems with specific properties.I nt his work, we showh ow the confinement of anthracene in aw ellchosen MOF host leads to reversible yellow-to-purple photoswitching of the fluorescence emission. This behavior has not been observed before for anthracene,e ither in pure form or adsorbed in other porous hosts.The photoresponse of the hostguest system is caused by the photodimerization of anthracene, which is greatly facilitated by the pore geometry,c onnectivity, and volume as well as the structural flexibility of the MOF host. The photoswitching behavior was used to fabricate photopatternable and erasable surfaces that, in combination with data encryption and decryption, hold promise in product authentication and secure communication applications.

Robust and scalable thin film deposition methods are key to realize the potential of metal-organic frameworks (MOFs) in electronic devices. Here, we report the first integration of the chemical vapor deposition (CVD) of MOF coatings in a custom reactor within a cleanroom setting. As a test case, the MOF-CVD conditions for ZIF-8 are optimized to enable smooth, pinhole-free, and uniform thin films on full 200 mm wafers under mild conditions. The single-chamber MOF-CVD process and the impact of the deposition parameters are elucidated via a combination of in situ monitoring and ex situ characterization. The resulting process guidelines will pave the way for new MOF-CVD formulations and a plethora of MOF-based devices. Apart from their applications in catalysis, 1 gas storage, 2 and separation processes, 3 metal-organic frameworks (MOFs), with their unprecedented specific surface areas and chemical modularity, show tremendous potential for integration in microelectronics. 4,5 As sensor coatings, their tunable composition and crystalline structure can be exploited for the selective adsorption of target molecules. 6-9 The low dielectric constant resulting from their porosity makes MOFs prime candidates for high-performance insulators in future logic processors. 10,11 To capitalize on the 10-6 cm 2 , were estimated using a CCD camera. All instruments were controlled using custom software. The generated current density (J) histograms were fitted using Gaussian functions for determining the peak center and width.

An advanced synthesis protocol for the preparation of Thin-Film Nanocomposite (TFN) membranes is presented.

A simple solvent-and catalyst-free method is presented for the synthesis of the large-pore metal−organic framework (MOF) MAF-6 (RHO-Zn(eIm) 2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤100°C. By translating this method to a chemical vapor deposition (CVD) protocol, crystalline films of a large-pore material could be deposited for the first time entirely from the vapor phase. A combination of positron annihilation lifetime spectroscopy (PALS) and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diameter ∼2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), pair distribution function (PDF), and extended X-ray absorption fine structure (EXAFS). The exceptional uptake capacity of MAF-6 in comparison to ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows. spectra; PALS data and implantation profiles; EDS data; fluorescence emission spectra (PDF)