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The fabrication of oriented, crystalline films of metal-organic frameworks (MOFs) is a critical step toward their application to advanced technologies such as optics, microelectronics, microfluidics and sensing. However, the direct synthesis of MOF films with controlled crystalline orientation remains a significant challenge. Here we report a one-step approach, carried out under mild conditions, that exploits heteroepitaxial growth for the rapid fabrication of oriented polycrystalline MOF films on the centimetre scale. Our methodology employs crystalline copper hydroxide as a substrate and yields MOF films with oriented pore channels on scales that primarily depend on the dimensions of the substrate. To demonstrate that an anisotropic crystalline morphology can translate to a functional property, we assembled a centimetre-scale MOF film in the presence of a dye and showed that the optical response could be switched 'ON' or 'OFF' by simply rotating the film.

The DONUT experiment has analyzed 203 neutrino interactions recorded in nuclear emulsion targets. A decay search has found evi-

The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed ντ charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6 × 10 17 protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed ντ CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section (ν +ν), relative to the well-known νe and νµ cross sections. The ratio σ(ντ )/σ(νe,µ) was found to be 1.37±0.35±0.77. The ντ CC cross section was found to be 0.72±0.24±0.36×10 −38 cm 2 GeV −1 . Both results are in agreement with expectations from the Standard Model.

A new approach for the fabrication of homogeneous HKUST‐1 [Cu3(BTC)2] coatings on copper metal plates, 3D objects, and as patterns, is here proposed. The conversion can be performed at room temperature in approximately 30 minutes using an aqueous ethanolic mixture. The two step conversion mechanism occurs via the formation of Cu(OH)2 nanotubes. Microscopic time‐course monitoring reveals the conversion steps. The adhesion of the metal organic‐framework (MOF) crystals, as well as the functional properties of the resulting supported catalyst, are successfully tested. The versatility of the conversion mechanism on different metal copper substrates is investigated as well; in particular, a photolithography protocol is proposed for the preparation of MOF patterns. This protocol offers several features (short processing time, applicability to any copper metal object, low cost of the equipment, room temperature conditions) that would make it favorable for basic research and industrial exploitation of MOF capabilities.

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.

Controlling the direction of molecular-scale pores enables the accommodation of guest molecular-scale species with alignment in the desired direction, allowing for the development of high-performance mechanical, thermal, electronic, photonic and...

The singlet fission (SF) dynamics of pentacene linear aggregate models are investigated using the quantum master equation method by focusing on the Frenkel excitonic (FE) coupling effects on the SF rate and double triplet (TT) yield as well as on their aggregate size dependences. It is found that for the dimer model, unrealistically large FE couplings are needed to provide significant effects on the SF dynamics, while for the larger aggregate models a realistic FE coupling causes significant variations in the SF dynamics: as increasing the aggregate size, the SF rate rapidly increases, attains the maximum at 8-mer (~3 times enhancement as compared to the non-FE-coupling case) and then decreases, approaching a stationary value after 12-mer, although the stationary TT yield at 20-mer remains slightly smaller than that in the non-FE-coupling case. These features are explained based on the relative relaxation factors between the adiabatic exciton states. The present results contribute to constructing the design guidelines for highly efficient SF aggregates. © 2018 Wiley Periodicals, Inc.