Three new polyether‐tethered dinickel–salphen complexes (2 a–c) have been synthesized and fully characterized by NMR spectroscopy, mass spectrometry, and elemental analyses. The binding affinity and selectivity of these complexes and of the parent mono‐nickel complex (1) towards dimeric quadruplex DNA have been determined by UV/Vis titrations, fluorescence spectroscopy, CD spectroscopy, and electrophoresis. These studies have shown that the dinickel–salphen complex with the longest polyether linker (2 c) has higher binding affinity and selectivity towards dimeric quadruplexes (over monomeric quadruplexes) than the dinickel–salphen complexes with the shorter polyether linkers (2 a and 2 b). Complex 2 c also has higher selectivity towards human telomeric dimeric quadruplexes with one TTA linker than the monometallic complex 1. Based on the spectroscopic data, a possible binding mode between complex 2 c and the dimeric G‐quadruplex DNA under study is proposed.

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Semiconducting nanowires, unlike bulk, can be grown in both wurtzite and zincblende crystal phases. this unique feature allows for growth and investigation of technologically important and previously unexplored materials, such as wurtzite AlGaAs. Here we grow a series of wurtzite AlGaAs nanowires with Al content varying from 0.1 to 0.6, on silicon substrates and through a comparative structural and optical analysis we experimentally derive, for the first time, the formula for the bandgap of wurtzite AlGaAs. Moreover, bright emission and short lifetime of our nanowires suggest that wurtzite AlGaAs is a direct bandgap material.Polytypism 1 is an exceptional property of nanowires and a new degree of freedom which enables the engineering of the electronic structure without change of material. For example, today's atomically-precise control over the crystal-phase switching in nanowires 2,3 allows to grow strain-free polytypic formations along the growth axis 4,5 , even small enough to form quantum dots 6,7 . The wurtzite phase is not observable at ambient conditions in bulk of any A III B V materials except for nitrides, while it can be obtained in nanowires. For this property and its technological implications, a great deal of attention has been drawn, in recent years, to nanowires system from scientific community 8-10 . However, for designing of novel structures and devices, knowledge of bandgaps and band alignments of the different crystal phases of new materials is crucial.In particular, Al X Ga 1-X As nanowires provide a promising platform for fabrication of advanced devices. For example, adding the Al component to the widely studied GaAs 11,12 allows to tune the emission in a wide range of wavelengths while, AlGaAs, having higher energy than GaAs, allows the combination of these two materials to fabricate strain-free quantum devices 13 .However, the knowledge about wurtzite AlGaAs is limited in the literature [14][15][16][17] , and is mainly grown as a shell around wurtzite GaAs core 15,16 . Importantly, the bandgap of wurtzite AlGaAs was neither predicted theoretically nor measured experimentally.In this work, we grow wurtzite AlGaAs nanowires, in a wide range of Al content x, and we present a comparative optical and structural study, empirically revealing the trend for the bandgap of wurtzite Al X Ga 1-X As. We grow our samples by Au-catalyzed vapor-liquid-solid technique in a molecular beam epitaxy (MBE) reactor (see methods section for details) obtaining high crystalline quality structures with any chosen Al content.

XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry window in high energy Astrophysics after more than 4 decades thanks to a detector that efficiently exploits the photoelectric effect and to X-ray optics with large effective area. XIPE uniqueness is time-spectrallyspatially-resolved X-ray polarimetry as a breakthrough in high energy astrophysics and fundamental physics. Indeed the payload consists of three Gas Pixel Detectors at the focus of three X-ray optics with a total effective area larger than one XMM mirror but with a low weight. The payload is compatible with the fairing of the Vega launcher. XIPE is designed as an observatory for X-ray astronomers with 75 % of the time dedicated to a Guest Observer competitive program and it is organized as a consortium across Europe with main contributions from

We report the design and performance of a 3-electrode device for real time in situ scanning transmission X-ray microscopy studies of electrochemical processes under both static (sealed, non-flow) conditions and with a continuous flow of electrolytes. The device was made using a combination of silicon microfabrication and 3D printing technologies. The performance is illustrated by results of a study of copper deposition and stripping at a gold working electrode. X-ray absorption spectromicroscopy at the Cu 2p edge was used to follow the evolution as a function of potential and time of the spatial distributions of Cu(0) and Cu(i) species electro-deposited from an aqueous solution of copper sulphate. The results are interpreted in terms of competing mechanisms for the reduction of Cu(ii).