1,721,500 research outputs found
Towards 2D layered hybrid perovskites with enhanced functionality : introducing charge-transfer complexes via self-assembly
No full textThis study broadens the family of 2D layered perovskites by demonstrating that it is possible to self-assemble organic charge-transfer complexes in their organic layer. Organic charge-transfer complexes, formed by combining charge-donating and charge-accepting molecules, are a diverse class of materials that can possess exceptional optical and electronic properties
<i>De Novo</i> enantioselective synthesis of hexafluorinated d-glucose
No full textWe report a de novo enantioselective synthesis of 2,3,4-trideoxy-2,2,3,3,4,4-hexafluoro-Dglycero-hexopyranose (“hexafluorinated D-glucose”), an iconic polar hydrophobic glycomimetic. The12-step synthesis features robust and reproducible chemistry and was achieved by incorporating an asymmetric dihydroxylation step to install the stereogenic center with excellent enantioselectivity (95:5 er). Virtual enantiopurity (> 99.5% ee) was further reached using a simple crystallisation procedure and the absolute confirmation was ascertained by X-ray analysis. The synthetic route also allowed the access to the novel hexafluorinated heptose derivative 2,3,4-trideoxy-2,2,3,3,4,4- hexafluoro-L-threo-heptopyranose
New platinum(II) and palladium(II) complexes with substituted terpyridine ligands: synthesis and characterization, cytotoxicity and reactivity towards biomolecules
No full textA series of palladium(II) (1–3) and platinum(II) chloride complexes (4 and 5) with 2,2′:6′,2′′-terpyridine (terpy) derivatives substituted at the 4′ position, was synthesized and fully characterized. Single crystal X-ray diffraction analysis of complexes 2, 3 and 5 showed tridentate coordination of the 4′-substituted terpyridine (terpy) ligands to the metal center. Moreover, in vitro cytotoxic activity of these complexes toward a panel of human cancer cell lines (lung cancer A549, colorectal cancer HCT116, ovarian cancer IGROV-1) and toward normal cell line HDF (dermal fibroblast) was determined by Trypan Blue exclusion assay. Overall, the tested compounds manifested a relevant cytotoxicity for the selected cancer cell lines with complex 4 also showing a modest cytotoxicity on the normal cell lines. To better understand the mode of action of these metal complexes, their reactivity with three model proteins, i.e. hen egg white lysozyme (HEWL), cytochrome c (cyt c) and ribonuclease A (RNase A) were comparatively investigated through ESI–MS analysis. The results highlighted a different behavior between the two series of complexes being platinum compounds more reactive toward RNase and cyt c than palladium compounds. Based on the obtained results, it is proposed that in presence of RNase A and cyt c, the platinum complexes undergo activation through release of labile ligands followed by binding to the protein. In contrast, palladium complexes revealed a far lower reactivity implying the likely occurrence of a different mechanism of action
2D layered perovskite containing functionalised benzothieno-benzothiophene molecules: Formation, degradation, optical properties and photoconductivity
Full text link2D layered hybrid perovskites are currently in the spotlight for applications such as solar cells, light-emitting diodes, transistors and photodetectors. The structural freedom of 2D layered perovskites allows for the incorporation of organic cations that can potentially possess properties contributing to the performance of the hybrid as a whole. In this study, we incorporated a benzothieno[3,2-b]benzothiophene (BTBT) alkylammonium cation into the organic layer of a 2D layered lead iodide perovskite. The formation and degradation of this material are discussed in detail. It is shown that the use of a solvent vapour annealing method significantly enhances the absorption, emission and crystallinity of films of this 2D layered perovskite as compared to regular thermal annealing. The photoconductivity of the films was determined using time-resolved microwave conductivity (TRMC) as well as in a device. In both cases, the solvent vapour annealed films show markedly higher photoconductivity than the films obtained using the regular thermal annealing approach.ChemE/Opto-electronic Material
Dinuclear NHC-gold(I)-thiolato and -alkynyl complexes : synthesis, anticancer activity, and catalytic activity in lactonization reactions
Full text linkA series of novel dinuclear NHC-gold-thiolato and -alkynyl complexes bearing aromatic linkers were successfully synthesized by an efficient and simple synthetic route. The catalytic activity of these complexes was tested in a lactonization reaction. The reaction proceeds in high efficiency, in short reaction time and under mild conditions, and is complementary to existing methods. Furthermore, the digold(i)-thiolato derivatives exhibit remarkable cytotoxicity towards several cancer cell lines
Low‐Dimensional Hybrid Perovskites Containing an Organic Cation with an Extended Conjugated System: Tuning the Excitonic Absorption Features
No full textLow-dimensional hybrid perovskites are receiving increased attention. One of the advantages of the low-dimensional hybrids over their 3D counterparts is their greater structural flexibility towards the incorporation of bigger, more complex, organic cations. In this communication, we introduce a pyrene derivative as an organic cation containing an extended pi-system for use in a variety of low-dimensional hybrids. We show that materials with different excitonic absorption features can be obtained by tuning the iodide/lead ratio in the precursor solutions, using the same pyrene cation. In this way, hybrids with optical characteristics corresponding to 2D, 1D and 0D hybrid perovskites are obtained. The formation and thermal stability of the different hybrids is analysed and compared
A simple synthetic entryway into new families of NHC-gold-amido complexes and their in vitro antitumor activity
No full textA simple synthetic pathway to Au-NHC amido complexes is described. Syntheses and isolation of [Au(NHC)((NRR2)-R-1)] complexes, bearing various NHC ligands and NH-containing heterocycles under mild conditions are reported. The in vitro anticancer activity of these gold-complexes was investigated on three human cancer cell lines. A number of these show comparable or even better antiproliferative activity than cisplatin. Noteworthy is the non-toxicity of most of the complexes on normal cells
Palladium- and ruthenium-based catalytic systems by N-heterocyclic carbene as ancillary ligands for cross-coupling and ring-closing metathesis (RCM) reactions
No full textSynthesis of cyclobutane-fused chromanones via gold-mediated photocatalysis
Full text linkEnergy transfer (EnT) photocatalysis has emerged as a valuable tool for constructing complex organic scaffolds via [2 + 2]-cycloaddition reactions. Herein, we present the use of [Au(SIPr)(Cbz)] as a sensitizer for the [2 + 2]-cycloaddition of coumarins and unactivated alkenes. Widely used in EnT catalysis, iridium and organic sensitizers proved less efficient under the examined catalytic conditions. The developed protocol permits the synthesis of cyclobutane-fused chromanones from readily available starting materials. A wide range of alkenes and substituted coumarins, including naturally occurring compounds, were reacted under mild conditions leading to structurally complex products with good functional group tolerance. Mechanistic studies reveal a previously overlooked reaction pathway for energy transfer catalysis involving coumarins
Dye-incorporated cyclodextrin metal-organic frameworks as luminescent (nano) platforms for temperature sensing
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