•Lead-free inorganic perovskite composites as new photocatalysts.•Enhanced visible light absorption ability.•Extended lifetime of the electron provides longer charge carrier separation.•Significant ...efficiency in the degradation of different organic pollutants.
Recently lead-free halide perovskite have shown great performances, especially in solar cell applications. On the other hand, graphitic carbon nitride g-C3N4 materials have been rising interest thanks to the tunable electronic structure and excellent physicochemical stability, which could serve as an excellent candidate for photocatalytic applications. In our research, we tried to overcome the low charge transportation efficiency and chemical instability anchoring a cesium/bismuth-based perovskite on g-C3N4 nanosheets to prepare composite photocatalyst based on nitrogen-iodine chemical bonding. Among different lead-free halide perovskite loads, the CNCSBI001 composite (g-C3N4:Cs3Bi2I9 10:0.1 w%) showed the better stability and an outstanding yield for photocatalytic degradation of organic compound in water solution under visible light irradiation. Hydrogen evolution test were also perform to test the activity of the synthesized compound under simulated solar light irradiation. The former study aim to provide insights on the use of halide perovskite-based Z-scheme photocatalyst for different photocatalytic applications.
Halogen bonding (XB) has been recently exploited as a significant tool for engineering crystals involving coordination and organometallic compounds as tectons. This review, in particular, focuses on ...extended networks based on XB between electron donor groups bound to metals and halo-pyridine and halo-tetrathiafulvalene moieties as electron acceptors. The influence of XB over the structures and the interactions between the organic frameworks and the metal centers is highlighted. The chemistry of some mononuclear systems forming XB is described in terms of tools for controlling supramolecular arrangement and chemical behaviour. Various computational studies on the energy of XB at different levels of sophistication, their advantages and limits concerning the evaluation of the interaction energy and modelling of its origin are critically surveyed. Modelling of a new example of interaction between Cp
2MH
2 (M
=
Mo, W) and CF
3I is reported together with the description of the electron density of the complex analyzed in terms of the Quantum Theory of Atoms in Molecules (QTAIM) model.
The Baeyer–Villiger oxidation of ketones to the corresponding esters or lactones is a valuable transformation that has been upgraded several times over the last century, from the original use of ...monopersulfuric acid as oxidant to more atom efficient and environmentally friendly oxidants such as hydrogen peroxide. The latter requires activation with organometallic complexes to explicate its oxidizing power. The catalytic version of the reaction can be achieved with several transition metal catalysts, but major differences are present among the various catalysts proposed in terms of scope of the reaction. In particular, most of the catalytic systems are active towards four-membered ring ketones leading to the corresponding substituted γ-butyro-lactones. Pt
II complexes characterized by the employment of chelating diphosphines turned out to be the most efficient in catalyzing the BV oxidation of a wider range of substrates, in particular cyclohexanones are suitable substrates and acyclic ketones can be converted into the corresponding esters, albeit with low turnover. As long as organometallic catalyzed BV reaction is concerned, Pt
II catalysts show the most versatile activity and selectivity. Such peculiar features are the result of the unique electronic properties of such metal combined with an easily tailored soft Lewis acid character modulated by the proper choice of the ancillary ligands. The enantioselective version of the reaction benefits from these properties and the compatibility of Pt
II species with water enabled the development of asymmetric catalytic BV reactions in water aided by the presence of micelles as dynamic self-assembled environments.
3D constructs are fundamental in tissue engineering and cancer modeling, generating a demand for tailored materials creating a suitable cell culture microenvironment and amenable to be bioprinted. ...Gelatin methacrylate (GelMA) is a well‐known functionalized natural polymer with good printability and binding motifs allowing cell adhesion; however, its tight micropores induce encapsulated cells to retain a non‐physiological spherical shape. To overcome this problem, blended GelMa is here blended with Pluronic F‐127 (PLU) to modify the hydrogel internal porosity by inducing the formation of larger mesoscale pores. The change in porosity also leads to increased swelling and a slight decrease in Young's modulus. All blends form stable hydrogels both when cast in annular molds and bioprinted in complex structures. Embedded cells maintain high viability, and while Neuroblastoma cancer cells typically aggregate inside the mesoscale pores, Mesenchymal Stem Cells stretch in all three dimensions, forming cell–cell and cell–ECM interactions. The results of this work prove that the combination of tailored porous materials with bioprinting techniques enables to control both the micro and macro architecture of cell‐laden constructs, a fundamental aspect for the development of clinically relevant in vitro constructs.
The increasing demand for 3D structures creating a suitable cell culture microenvironment and amenable to be bioprinted requires the development of novel materials. Here, a Gelatin methacrylate (GelMA)/Pluronic (PLU) blend with optimized porosity favoring cells physiological behaviors both in Neuroblastoma cancer cells and Mesenchymal Stem Cells, is proposed and characterized.
The enantioselective Baeyer–Villiger oxidation of cyclic ketones is a challenging reaction, especially when using environmentally friendly oxidants. The reaction was carried out in water by using ...soft Lewis acid PtII complexes that have chiral diphosphines as well as monophosphines. Addition of a surfactant is crucial, which leads to the formation of micelles that act as nanoreactors in which the substrate and catalyst encounter each other in an ordered medium that in several cases positively influences both the conversion and the selectivity of the reactions. This is due to the combination of the hydrophobic effect (which confines the components of the reaction in the micelles), together with supramolecular interactions between the partners within the ordered palisade provided by the alkyl chains of the surfactant. For the oxidation of meso‐cyclobutanones, addition of surfactant allowed the reaction to proceed in high yields and the enantiometic excess (ee; 56 %) was higher than in organic solvents. Subsequent extension to meso‐cyclohexanones resulted in a general decrease in yields but an enhancement of enantioselectivity (ee up to 92 %) moving from organic to water–surfactant media, regardless of the substrate or the catalyst employed. Different behaviour was observed with chiral cyclobutanones 7 and 10: with 7 the best catalyst was 1 g, whereas with the larger substrate, 10, complexes 1 a–b performed better in terms of enantioselectivity. Each combination of substrate, catalyst and surfactant is a new system and supramolecular reciprocal interactions together with the hydrophobic character of the counterparts play crucial roles. The asymmetric Baeyer–Villiger oxidation in water catalyzed by 1 a–h in the presence of micelles is a viable reaction that often benefits from the hydrophobic effect, leading to substantial increases in enantioselectivity.
Soapy is better! Enantioselective Baeyer–Villiger oxidation of cyclic ketones in water mediated by hydrogen peroxide was achieved by using PtII catalysts bearing monodentate as well as bidentate chiral phosphines, with the aid of surfactants (see picture; SDS=sodium dodecylsulfate). Micelle formation is crucial, allowing intimate contact between the reagents and catalyst and enhancing enantioselectivity.
Inside Back Cover: Neuroblastoma cancer cells aggregating inside the mesoscale pores of a bioprinted construct. The combination of tailored porous materials with 3D bioprinting techniques enables to ...control both the micro and macro architecture of cell‐laden constructs. The generation of improved in vitro mimics of in vivo tissues (healthy or diseased) would help precision medicine and the development of patient specific therapeutic approaches. This is reported by Elisa Cimetta and co‐workers in article number 2200357.
New Ru(II) complexes encompassing α-diimine ligands were synthesized by reacting ruthenium precursors with α-diimine hydrazones. The new ligands and Ru(II) complexes were analyzed by analytical and ...various spectroscopic methods. The molecular structures of L1 and complexes 1, 3, and 4 were determined by single-crystal XRD studies. The results reveal a distorted octahedral geometry around the Ru(II) ion for all complexes. Moreover, the new ruthenium complexes show efficient catalytic activity toward the C–N and C–C coupling reaction involving alcohols. Particularly, complex 3 demonstrates effective conversion in N-alkylation of aromatic amines, α-alkylation of ketones, and β-alkylation of alcohols.
Back Cover: In article number 2100409 by Voto Di Novo and co‐workers, the incorporation of tantalum oxide into trimethylammonium‐functionalized polyethylene pyrrole‐co‐polyethylene ketone is carried ...out for the preparation of inorganic–organic hybrid anion exchange membranes, which are promising candidates for application in electrochemical energy conversion devices.
•Municipal Solid Waste (MSW) composition and aging.•Long-term waste characterization and storage capacity.•MSW compounds leachability and residual emission potential.
The storage capacity and the ...potentially residual emissions of a stabilized waste coming from a landfill simulation experiment were evaluated. The evolution in time of the potential emissions and the mobility of some selected elements or compounds were determined, comparing the results of the stabilized waste samples with the values detected in the related fresh waste samples. Analyses were conducted for the total bulk waste and also for each identified category (under-sieve, kitchen residues, green and wooden materials, plastics, cellulosic material and textiles) to highlight the contribution of the different waste fractions in the total emission potential.
The waste characterization was performed through analyses on solids and on leaching test eluates; the chemical speciation of carbon, nitrogen, chlorine and sulfur together with the partitioning of heavy metals through a SCE procedure were carried out.
Results showed that the under-sieve is the most environmentally relevant fraction, hosting a consistent part of mobile compounds in fresh waste (40.7% of carbon, 44.0% of nitrogen, 47.6% of chloride and 40.0% of sulfur) and the greater part of potentially residual emissions in stabilized waste (88.4% of carbon, 90.9% of nitrogen, 98.4% of chloride and 91.1% of sulfur). Landfilled Municipal Solid Waste (MSW) proved to be an effective sink, finally storing more than 55% of carbon, 53% of nitrogen, 33% of sulfur and 90% of heavy metals (HM) which were initially present in fresh waste samples. A general decrease in leachable fractions from fresh to stabilized waste was observed for each category. Tests showed that solid waste is not a good sink for chlorine, whose residual non-mobile fraction amounts to 12.3% only.
