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Treating conic tetra-para-ethylacetato-calix[4]arene (1) with 2.2 equivalents of K2CO3 and 4 equivalents of 6-bromomethyl-6′-methyl-2,2′-bipyridine affords the expected fully substituted podand, mainly in its 1,3-alternate conformation (2). This tube-like bipyridyl derivative 2 was subjected to complexation studies with CoCl2·6H2O to give a blue tetra cobalt(II) complex species (3). This complex displays a unique group of 6 aromatic bipyridyl 1H-NMR resonance signals demonstrating its high symmetry, while X-ray diffraction studies showed the presence of 3 expected tetrahedral bpy(CoCl2) units and 1 original trigonal bipyramidal unit involving the adjunction of a fifth ligand assumed to be H2O that could participate in the crystal scaffold. [ABSTRACT FROM AUTHOR]

Abstract: A series of layered titanates containing in the interlayer space tris(2,2′-bipyridyl)ruthenium(II) [] or methyl viologen (MV2+) or both has been prepared and characterized by elemental analyses, XRD, and optical and vibrational spectroscopy. Incorporation of and MV2+ is confirmed by the increase of the distance between the titanate layers. The presence of in the material is also revealed in optical spectroscopy where the ligand to metal charge transfer band appearing at λ max 460nm is observed. Also incorporation of MV2+ leads to the observation of the charge transfer complex band with the titanate host from 350 to 650nm. These solids are active for the photocatalytic hydrogen generation from water when colloidal platinum as catalyst and EDTA as sacrificial electron donor are present in the solution. The maximum efficiency was obtained for a solid consisting of layered titanate containing a 10.2wt.% loading of incorporated in the titanate layers and MV2+ and Pt nanoparticles in the aqueous solution. This heterogeneous system produced about one-half the hydrogen generated for the conventional homogeneous system where all the components [, MV2+, Pt, and EDTA] are in solution, with the advantage that it can be used as film or recovered by filtration from the aqueous medium. [Copyright &y& Elsevier]

From the root barks of a Central African tree Millettia dubia De Wild. (Fabaceae), ten previously undescribed oleanane-type glycosides were isolated by various chromatographic protocols. Their structures were elucidated by spectroscopic methods, mainly 2D NMR experiments and mass spectrometry, as mono- and bidesmosidic glycosides of mesembryanthemoidigenic acid, hederagenin and oleanolic acid. The stimulation of the sweet taste receptor TAS1R2/TAS1R3 by these glycosides was evaluated, and structure/activity relationships were proposed. Two of them showed an agonist effect on TAS1R2/TAS1R3. [Display omitted] • Ten different oleanolic acid glycosides were isolated. • Their structures were elucidated by extensive 2D NMR analyses. • The stimulation of the sweet taste receptors TAS1R2/TAS1R3 was evaluated. • Some structure/activity relationships were discussed. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) is a promising technique for the conversion of lignocellulosic biomass, such as two-phase olive mill waste (TPOMW). However, the resulting generated aqueous phase (AP) rich in organic compounds is harmful if directly discharged in the environment. In this work, the use of recycled aqueous phase from the HTC process of TPOMW is evaluated as a reactive medium. The evolution of products yields, quality, morphology chemical structure, and composition with AP recycling runs are investigated by different analytical methods (Nuclear Magnetic Spectroscopy 1H and solid state 13C, Scanning Electron Microscopy, Elemental analysis, Proximate analysis, Fourier Infrared Transform spectroscopy, Total organic carbon, and total nitrogen). The results revealed significant improvement in the hydrochar yield and energy yield that increase 47.4 wt% to 53.0 wt% and 72.8%–81.3%, respectively. The increase in the number of recycling experiments promotes the lignin condensation as well as the polymerization of AP intermediates into microspheres. These phenomena lead to the increase in hydrochar yield as well as the modification of its micro-surface into a smooth porous surface through the recycling runs. Additionally, FT-IR and the solid state 13C NMR analysis demonstrated that AP recycling has no noticeable effect on the chemical structure of the produced hydrochars. Further analysis of the AP demonstrated that the total organic carbon and total nitrogen increase significantly after the first recycling run from 17.3 to 26.5 g/L and 0.4–0.6 g/L, respectively. The 1H NMR analysis revealed that AP is mainly formed by aliphatic and aromatic compounds. [Display omitted] • Aqueous phase recycling increases hydrochar yield by 47.4 wt.%-53.0 wt.% and energy yield by 72.8%-81.3% post-first run. • SEM shows hydrochars with open pores after aqueous phase recycling. • TOC increases from 17.3 to 26.5 g/L and TN from 0.4 to 0.6 g/L after 1st run. • 1H NMR detects aliphatic & aromatic compounds in the aqueous phase. [ABSTRACT FROM AUTHOR]

Nickel and iron aluminide coatings were identified as possible candidates for hardfacing materials in Sodium Fast Reactors. Both coatings were developed on two steel grades of interest for the next French Sodium Fast Reactor prototype, 316L(N) and T91. Pack cementation and slurry were employed as aluminization processes. The compatibility of all coatings with purified Na was evaluated at 550 °C for exposure times up to 4250 h. All coatings evidenced high chemical stability in Na even though Na penetration and slow coating dissolution could be evidenced. The penetration depth of Na was observed to depend on the coating nature induced by the deposition process. [ABSTRACT FROM AUTHOR]

Abstract: A zeolite beta–silicalite-1 composite was prepared by growing polycrystalline silicalite-1 shells on single micron-sized zeolite beta crystals. The obtained core–shell material was employed for the separation of hexane isomers. Gravimetric uptake measurements revealed that the silicalite-1 shell acted as a membrane that controlled the transport to zeolite beta core. The positive impact of the silicalite-1 membrane on the separation of mono- and di-branched hexane isomers was confirmed by breakthrough experiments. The core–shell composite material allowed more selective separation of mono- and di-branched isomers than either of its components alone and had a significantly higher adsorption capacity than silicalite-1. [Copyright &y& Elsevier]