Metal-Free Intermolecular Azide-Alkyne Cycloaddition Promoted by Glycerol
作者:Marta Rodríguez-Rodríguez、Emmanuel Gras、Miquel A. Pericàs、Montserrat Gómez
DOI:10.1002/chem.201503858
日期:2015.12.14
Metal‐free intermolecular Huisgen cycloadditions using nonactivated internal alkynes have been successfully performed in neat glycerol, both under thermal and microwave dielectric heating. In sharp contrast, no reaction occurs in other protic solvents, such as water, ethanol, or diols. DFT calculations have shown that the BnN3/glycerol adduct promotes a more important stabilization of the corresponding
Synthesis of Ferrocene Oxazoline N,O ligands and Their Application in Asymmetric Ethyl- and Phenylzinc Additions to Aldehydes
作者:Chris Nottingham、Robert Benson、Helge Müller-Bunz、Patrick J. Guiry
DOI:10.1021/acs.joc.5b01766
日期:2015.10.16
The synthesis of a range of novel gem-disubstituted ferrocene–oxazoline ligands and their application in both the asymmetric ethyl- and phenylzinc additions to aldehydes is reported. These studies reveal that gem-disubstitution of i-Pr-containing ferrocene oxazolineligands results in increased enantioselectivity compared to their unsubstituted counterparts. Utilizing zinc catalysis, these ligands provided
Synthesis, characterization and use of highly stable trimethyl sulfonium tin(IV) halide defect perovskites in dye sensitized solar cells
作者:Mohamed M. Elsenety、Andreas Kaltzoglou、Maria Antoniadou、Ioannis Koutselas、Athanassios G. Kontos、Polycarpos Falaras
DOI:10.1016/j.poly.2018.05.001
日期:2018.8
We report here on the crystal structure and physical properties of ((CH3)(3)S)(2)SnX6 (X = Cl, Br, I) compounds as well as the application of ((CH3)3S)(2)SnI6 in dye-sensitized solar cells. Powder X-ray diffraction and Rietveld analysis show that the materials form a cubic structure with a OD network of [SnX6] octahedra, which can be considered as a defect variant (AB(0.5)X(3)) of the perovskite archetype (ABX(3)). The electronic band gaps of ((CH3)(3)S)(2)SnX6 were determined by UV-Vis reflectance spectroscopy at 4.1, 2.9 and 1.4 eV for X = Cl, Br, and I, respectively. The direct bandgap and its relative decrease in the order of light to heavy halide was independently verified by density-of-states calculations. According to Raman spectroscopy, the lattice vibrations also depend largely on the halogen atom. The air-stable and non-toxic ((CH3)(3)S)(2)SnI6 compound was incorporated in electrolyte-free, dye -sensitized solar cells based on the Z907 chromophore chemisorbed onto mesoporous titania electrodes. A power conversion efficiency of 5% is achieved for these photovoltaic devices, confirming efficient charge transport in the bulk ((CH3)(3)S)(2)SnI6 and hole extraction at the perovskite-Pt interface. (C) 2018 Elsevier Ltd. All rights reserved.