A photoswitchable strapped calix[4]pyrrole receptor: highly effective chloride binding and release

A stiff-stilbene strapped calix[4]pyrrole receptor can be reversibly switched by light between a strong chloride-binding Z-isomer and a very weakly binding E-isomer. The light-induced switching process is monitored by UV-Vis and ¹H NMR spectroscopy and chloride binding is studied in detail using both ¹H NMR and ITC titrations in DMSO and MeCN. In DMSO, at millimolar concentrations, switching from a fully bound to an almost fully unbound state can be triggered. Quantification of the binding constants in MeCN reveals an extraordinary 8000-fold affinity difference between the Z- and E-isomer. Single crystal X-ray crystallographic analysis gives insight into the structure of the photogenerated E-isomer and the geometry of the chloride-bound receptors is optimized by DFT calculations. The highly effective control of binding affinity demonstrated in this work opens up new prospects for on demand binding and release in extractions and photocontrol of membrane transport processes, among other applications.

A reconfigurable calix[4]pyrrole receptor containing a stiff-stilbene strap can be switched by light between a strong and weak binding form, showing an 8000-fold affinity difference for chloride.     

Zur Trennung des Aethylalkohols

Ohne Zusammenfassung     

First Spectra from a New, Wide Band, Hybrid Digital Correlator Spectrometer for the First-HIFI Instrument

We have designed and built a new, wide band, modulable resolution spectrometer, in view of full astronomical qualifying tests, and to prepare future models for the FIRST satellite's heterodyne instrument. Our spectrometer, a hybrid digital Autocorrelator, offers flexibility in terms of bandwidth (from 170MHz to 680MHz) and resolution (from 700kHz to 3MHz). This spectrometer required the development of a dedicated analog filter bank, homemade samplers, and the design of full custom GaAs integrated circuits.Laboratory tests have shown excellent agreement with expected performances and observations performed with the IRAM 30-m radiotelescope have qualified its capabilities. Despite the relatively limited number of channels of our current prototype compared to others spectrometers, the main advantages are its stability (inherent to digital technique), and its spectral versatility.Recent microelectronics advances and rad-tolerance of our spectrometer components are used to prepare a new, compact, and low power consumption autocorrelator in view of a flight model for HIFI, the heterodyne instrument on the ESA cornerstone mission FIRST.     

ortho‐, meta‐, and para‐Dihydroindenofluorene Derivatives as Host Materials for Phosphorescent OLEDs

This work reports the first structure–properties relationship study of ortho [2,1‐c]‐, meta [1,2‐a]‐, and para [1,2‐b]dihydroindenofluorenes, highlighting the influence of bridge rigidification on the electronic properties. This study has made it possible to devise an extended π‐conjugated molecule with both a high triplet state energy level and excellent thermal and morphological stability. As a proof of concept, dihydroindenofluorenes were used as the host in sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs) w ith high performance.     

Synthesis and luminescence properties of new red-shifted absorption lanthanide(III) chelates suitable for peptide and protein labelling

The synthesis and photo-physical properties of an original bis-pyridinylpyrazine chromophore efficiently sensitising europium(III) and samarium(III) are described. The corresponding lanthanide(III) complexes display in aqueous solutions a maximum excitation wavelength which is significantly red-shifted compared to the usual terpyridine-based chelates, and a valuable luminescence brightness above 2,000 dm(3) mol(-1) cm(-1) at 345 nm was obtained with a europium(III) derivative. Further functionalisation with three different bioconjugatable handles was also investigated and their ability to efficiently label a model hexapeptide was evaluated and compared. Finally, the best bioconjugatable europium(III) chelate was used in representative labelling experiments involving monoclonal antibodies and the luminescence features of the corresponding bioconjugates remained satisfactory.     

Cupric superoxo-mediated intermolecular C-H activation chemistry

The new cupric superoxo complex [LCu(II)(O(2)(?-))](+), which possesses particularly strong O-O and Cu-O bonding, is capable of intermolecular C-H activation of the NADH analogue 1-benzyl-1,4-dihydronicotinamide (BNAH). Kinetic studies indicated a first-order dependence on both the Cu complex and BNAH with a deuterium kinetic isotope effect (KIE) of 12.1, similar to that observed for certain copper monooxygenases.