Search results for "Catalysis"
showing 10 items of 5944 documents
Synthesis and Redox Behaviour of the Chalcogenocarbonyl Dianions, [(E)C(PPh2S)2]2−: Formation and Structures of Chalcogen−Chalcogen Bonded Dimers and…
2010
The lithium salts of the chalcogenocarbonyl dianions [(E)C(PPh(2)S)(2)](2-) (E=S (4 b), Se (4 c)) were produced through the reactions between Li(2)[C(PPh(2)S)(2)] and elemental chalcogens in the presence of tetramethylethylenediamine (TMEDA). The solid-state structure of {[Li(TMEDA)](2)[(Se)C(PPh(2)S)(2)]}-[{Li(TMEDA)}(2)4 c]-was shown to be bicyclic with the Li(+) cations bis-S,Se-chelated by the dianionic ligand. One-electron oxidation of the dianions 4 b and 4 c with iodine afforded the diamagnetic complexes {[Li(TMEDA)](2)[(SPh(2)P)(2)CEEC(PPh(2)S)(2)]} ([Li(TMEDA)](2)7 b (E=S), [Li(TMEDA)](2)7 c (E=Se)), which are formally dimers of the radical anions [(E)C(PPh(2)S)(2)](-) (.) (E=S (5 …
A Molecular Metal Ferromagnet from the Organic Donor Bis(ethylenedithio)tetraselenafulvalene and Bimetallic Oxalate Complexes
2003
A new dual-function hybrid molecular material has been obtained from the organic donor bis(ethylenedithio)tetraselenafulvalene and the honeycomb oxalate-based bimetallic network [MnCr(ox)3]-. This multilayer material consists of layers of the inorganic anionic 2D network, responsible for the appearance of ferromagnetic ordering below 5.3 K, alternating with segregated layers of the organic cation radical responsible for the transport properties: metal-like conductivity is observed from room temperature down to 150 K.
Formation of Pyrazol-1,3,4-Thiadiazoles through 1,3-Dipolar Cycloadditions of 3-Thioxo-[1,2,4]-Triazepin-5-one with Nitrilimines: An Experimental and…
2009
In this work the results of experimental and computational study of the title compounds and some ancillary compounds are reported. Two bicyclic pyrazol-1,3,4-thiadiazole derivatives were synthesized by reaction between 6-dimethylaminomethylene-3-thioxo-[1,2,4]- triazepin-5-one 1 and several nitrilimines 2a-f to give corresponding spirocycloadducts 3a-f, which undergo a rapid rearrangement leading to the new bicyclic compounds, 4a-f and 5a-f. These obtained bicyclic products were characterized by 1H and 13C NMR spectroscopy and finally by X-ray crystallography. Theoretical calculations have been carried out using DFT methods to rationalize the formation of the two new bicyclic compounds. Two…
Stereocontrolled synthesis of azeto[2,1-b] quinazolines bearing three stereocenters via the intramolecular [2+2] cycloaddition between ketenimines an…
2004
Abstract A highly stereoselective synthesis of azeto[2,1- b ]quinazolines bearing three stereocenters (C1, C2, and C8) has been achieved via intramolecular [2+2] cycloaddition between ketenimine and imine functions supported on an ortho -benzylic scaffold. An asymmetric center adjacent to the iminic nitrogen atom, the future C8 carbon of the bicyclic product, efficiently controls the absolute configuration of the two new stereogenic carbon atoms of the azetidine ring, C1 and C2.
Pyrene derived functionalized low molecular weight organic gelators and gels
2008
Pyrene derived binary functionalized low molecular weight organic gelators (FLMOGs) and gels thereof in selected organic solvents were synthesized and characterized. The functionality refers to a functional group that does not take part in formation of the supramolecular gel network, but remains free and available for other purposes, such as to bind nanoparticles or other molecules into the gel structure. Functional groups were observed to disturb gel formation strongly, if they interact with each other within the same supramolecule due to the formation of competitive structures. Preventing such interactions restored the original gel properties. A gel with weaker supramolecular bonding than…
Halogen Bonded Analogues of Deep Cavity Cavitands
2014
The first examples of halogen bonded analogues of deep cavity cavitands with guest binding properties, formed between N-alkyl ammonium resorcinarene halides as acceptors and bromotrichloromethane as the donor, are reported in the solid state and in solution.
Insights into the production of upgraded biofuels using Mg-loaded mesoporous ZSM-5 zeolites
2020
9 figures, 6 tables.-- Supplementary information available.-- https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html
Promoting Deoxygenation of Bio-Oil by Metal-Loaded Hierarchical ZSM-5 Zeolites
2016
3 Figuras.- 5 tablas.-1 Esquema.- This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acssuschemeng.5b01606 ”
Biocatalysis and biorecognition in nonaqueous media. Some perspectives in analytical biochemistry
1995
Biocatalysis and, to a lesser extent, biorecognition in non-aqueous media (including organic solvents as well as supercritical fluids and gases) constitute at present an exciting research area which has already demonstrated its biotechnological potential in numerous, varied applications. Less attention, however, has been paid to its analytical possibilities, even though many advantages have been postulated and a wide range of poorly water-soluble analytes are present in samples (or waste materials) from food and drink, petrochemical, pharmaceutical, military and other industries. The main approaches, developed in recent years to exploit the use of enzymes, antibodies or antibody mimics in w…