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Anthracene-, benzophenone-, and anthraquinone-based UV photoinitiators have been, respectively, covalently grafted on the [Mo6O19]2–polyoxometalate (POM) platform, affording highly colored charge transfer organo-imido Lindqvist complexes. It has been evidenced that photosystems combining N-methyldiethanolamine (MDEA) as the electron donor and these hybrid POMs promote free-radical photopolymerization of acrylate monomer derivatives under irradiation in the visible range, while in similar conditions, no polymerization was observed considering as photoinitiators a mixture of the organic and POM precursors. After 800 s, acrylate conversion yields up to 90% under 405 nm LED irradiation and 50% under 470 nm LED irradiation were thus obtained considering the POM-imidoanthraquinone (POM-AQ) compound. This shows that such organo-imido Lindqvist species can represent new easy-to-synthesize, efficient visible-light photoinitiators. Moreover, due to the presence of the POM, coatings prepared using the POM-AQ/MDEA/soybean oil epoxidized acrylate photosystem exhibit excellent mechanical properties, with very good flexibility, resistance to brittle fracture, and adherence to the steel. Finally, POM-AQwas shown to have a remarkable capacity to generate singlet oxygen species under visible light irradiation, and the antibacterial activity against Staphylococcus aureusunder solar light of the related POM-derived surface has been demonstrated.

This study reports the synthesis of pure ZnFe2O4, pure Mn2O3nanoparticles and ZnFe2O4/Mn2O3nanocomposites by a simple coprecipitation method. The prepared samples were characterized by X-ray diffraction, transmission electron microscopy, N2adsorption/desorption, and photoluminescence spectroscopy (PL). The prepared samples were further applied as photocatalysts for UV-exposed degradation of nitrobenzene at 254 nm. The photocatalytic performance showed that ZnFe2O4/Mn2O3nanocomposites with various Mn2O3content exhibited a higher activity compared to that of pure ZnFe2O4and Mn2O3. Furthermore, among the prepared nanocomposites, the best photocatalytic performance was exhibited by 0.9ZnFe2O4/0.1Mn2O3nanocomposites. The improved photocatalytic activity was mainly attributed to the separation of electron–hole pairs, as verified by PL analysis. To achieve the highest degradation rate, the photodegradation reaction was carried out in the presence of various catalyst doses, in acidic, neutral, and basic mediums and at different reaction temperatures. Finally, the compounds produced from the photodegradation reaction were determined by applying the optimal experimental conditions.

The photochemical electrocyclization reaction of the title compound in the presence of β-cyclodextrin was examined in different conditions. No enantioselectivity was observed in solution, but solid-state reactions of a 1:1 complex as a suspension or a thin film, followed by reduction, provided (1R,5R)-2-azabicyclo[3.2.0]heptan-3-one in isolated yields up to 79% and with ee values up to 45%.

The host–guest interactions between the spherical porous Keplerate anion, [Mo132O372(CH3CO2)30(H2O)72]42–(abbreviated {Mo132}) and the tetramethylammonium cation have been investigated extensively by one- and two-dimensional (EXSY, ROESY, and DOSY) and variable-temperature NMR. Evidence of two inner receptor sites specific for a NMe4+guest appears consistent with a quite striking compartmentalization phenomenon. ROESY NMR analyses showed that both sites exhibit a close spatial proximity with the hanging inner acetate groups, while a quantitative EXSY study revealed that these two sites are differentiated by their exchange rates. These NMR data support the hypothesis that these two inner sites could be delimited by the hanging inner acetate groups forming triangular (S1) or pentagonal (S2) hydrophobic pockets on the inner side of the capsule wall. Furthermore, the stability constants associated with the trapping process of the NMe4+guest on both the S1 and S2 sites have been determined, showing that the stability constant of the S1 sites decreases significantly as the concentration of the capsule increases gradually, while that of the S2 sites remains nearly unaffected. Such an observation has been interpreted as a result of the plugging process of the {Mo9O9} pores by the counterions NH4+, which causes unfavorable electrostatic interactions for the NMe4+coordination on the proximal S1 site. Finally, the thermodynamic parameters of the NMe4+transfer from the solvated situation to the interior of the capsule were estimated from variable-temperature NMR experiments that provide the split of the global process into two successive events corresponding to the plugging and transfer across the inorganic shell.

A sol–gel method using Ba and Al isopropylates and iron nitrate has been used to synthesise barium hexaaluminate partially substituted with iron. After calcination under oxygen at 1200°C the β-alumina structure was obtained. Formation of the mixed BaFexAl12-xO19phase occurred for x=1–4. XRD measurements showed a good crystallinity of the structure and expansion of unit cell parameters due to the presence of larger Fe3+ions substituting Al3+ones in octahedral sites only. Mössbauer spectroscopy revealed that Fe3+ions are present in four different octahedral sites slightly distorted. Catalytic activity in methane combustion showed that an optimum was obtained for solid containing 2 Fe ions per unit cell: the increase of the amount of introduced iron was counterbalanced by the decrease of specific surface area. Intrinsic activities have been calculated for the four solids in both the fresh and aged states. It is observed that increasing iron content increases relative activities in the same ratio as the populations of iron located in two sites as deduced from Mössbauer spectroscopy. It is then tentatively assumed that activity is attributed to octahedrally coordinated Fe3+ions in some specific sites.

The thermal stability of the monodiazohydroborate NMe4[1-N2B10H9] was studied by thermogravimetric analysis. Under two different atmospheres (air and argon), the thermal decomposition starts at a temperature between 140 and 160 °C. The decomposition residue obtained was separated on a silica gel column. ¹¹B NMR, IR and electrospray mass spectroscopy analyses of the different fractions separated showed that the above decomposition produces (NMe4)2[B20H18] as major product (90%), along with smaller amounts of residual NMe4[1-N2B10H9] (5%), (NMe4)2[B12H12] and boric acid. Copyright © 2003 John Wiley & Sons, Ltd.

The thermal stability of the monodiazohydroborate NMe4[1‐N2B10H9] was studied by thermogravimetric analysis. Under two different atmospheres (air and argon), the thermal decomposition starts at a temperature between 140 and 160 °C. The decomposition residue obtained was separated on a silica gel column. 11B NMR, IR and electrospray mass spectroscopy analyses of the different fractions separated showed that the above decomposition produces (NMe4)2[B20H18] as major product (90%), along with smaller amounts of residual NMe4[1‐N2B10H9] (5%), (NMe4)2[B12H12] and boric acid. Copyright © 2003 John Wiley & Sons, Ltd.

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