Browsing Τμήμα Χημείας / Department of Chemistry by Title
Now showing items 890-909 of 1302
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Article
Regeneration of aged commercial three-way catalysts using CI-containing reagents
(2013)The present work is focused on applying washing treatments using Cl-containing reagents, such as di-chloroacetic acid (DCA) for the first time, and 1,2-di-chloropropane, DCP (0.1 M) solutions in regaining the activity and ...
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Article
Regeneration of aged commercial three-way catalytic converters
(2009)The present work demonstrates for the first time that rejuvenation of the catalytic activity of full-scale aged commercial three-way catalytic (TWC) converters is feasible after treatment with weak oxalic acid solution ...
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Article
Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments
(2006)Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. ...
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Article
Regeneration of three-way automobile catalysts using biodegradable metal chelating agent-S, S-ethylenediamine disuccinic acid (S, S-EDDS)
(2011)Regeneration of the activity of three-way catalytic converters (TWCs) was tested for the first time using a biodegradable metal chelating agent (S, S-ethylenediamine disuccinic acid (S, S-EDDS). The efficiency of this novel ...
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Article
Regio- and stereoselective synthesis of enantiomerically pure [60]fullerene tris-adducts with an inherently chiral e,e,e addition pattern
(2005)The synthesis and flash column chromatographic separation of c enantiomerically pure tris-adducts of C60 with an e,e,e-addition pattern is achieved via cyclopropanation with chiral D3-symmetrical cyclo-tris(malonate) ...
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Article
Regioselective Fluorination of 7-Oxo-1,2,4-benzotriazines Using Selectfluor
(2019)7-Oxo-1,2,4-benzotriazines (benzo[1,2,4]triazin-7-ones) are reversible thioredoxin reductase inhibitors that exhibit very strong correlations to pleurotin. In this article, we provide the first synthesis of fluorinated ...
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Article
Regioselective geminal dichloride reactivity of 3,4,4,5-tetrachloro-4H-1,2,6-thiadiazine: Access to 4,4-dioxo- and dithio-ketals
(2016)Treatment of 3,4,4,5-tetrachloro-4H-1,2,6-thiadiazine (2) with selected alkanols, arenols and thiols led to regiospecific substitution of both geminal C-4 chlorines resulting in the formation of ketal or thioketal ...
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Article
Regioselective hydrodehalogenation of 3,5-dihaloisothiazole-4- carbonitriles: Synthesis of 3-haloisothiazole-4-carbonitriles
(2011)3,5-Dibromoisothiazole-4-carbonitrile 1 treated with Zn or In dust (5 equiv) and HCO2H undergoes regioselective hydrodebromination to give 3-bromoisothiazole-4-carbonitrile 3 in 70-74% yield. Similarly, 5-bromo and iodo ...
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Article
Regioselective synthesis and zone selective deprotection of [60]fullerene tris-adducts with an e,e,e addition pattern
(2005)D3h-symmetrical tripodal tris(malonate) tethers have been used for the synthesis of [60]fullerene tris-adducts with an e,e,e addition pattern bearing topologically distinct polar and equatorial addend zones that can ...
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Article
Regiospecific Suzuki coupling of 3,5-dichloroisothiazole-4-carbonitrile
(2003)3,5-Dichloroisothiazole-4-carbonitrile 1 reacts with aryl- and methylboronic acids to give in high yields the 3-chloro-5-(aryl and methyl)-isothiazole-4-carbonitrile 2 regiospecifically. The reaction was optimized with ...
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Article
Regiospecific synthesis of 5,7-disubstituted quinoxalino[2,3-b]phenazines
(2002)Hydrogenation of the readily prepared dinitrobenzenediamines 7 followed by air oxidation affords the green colored 5,7-disubstituted-5H,12H-quinoxalino[2, 3-b]phenazines 3 in good yields. Mechanistic rationale, compound ...
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Article
Regular and inverse polyampholyte hydrogels: A detailed comparison
(2016)Two series of polyampholyte (PA) hydrogels were prepared via reversible addition-fragmentation chain transfer polymerization, followed by removal of the protecting group of the acidic monomer repeating units (methacrylic ...
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Article
Reinvestigating the reaction of 1H-pyrazol-5-amines with 4,5-dichloro-1,2,3-dithiazolium chloride: A route to pyrazolo[3,4-c]isothiazoles and pyrazolo[3,4-d]thiazoles
(2014)The reaction of Appel salt 1 with 1H-pyrazol-5-amines 2 gives main products N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)-1H-pyrazol-5-amines 3, and 6H-pyrazolo[3,4-c]isothiazole-3-carbonitriles 5, together with several minor ...
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Article
Reinvestigating the synthesis of N-arylbenzamidines from benzonitriles and anilines in the presence of AlCl3
(2010)The preparation of N-phenylbenzamidine 3a from the reaction between benzonitrile Ia and aniline in the presence of AId3 is reinvestigated with respect to mode of reagent addition, reaction temperature and Lewis acid ...
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Article
Relative stabilities and hydride affinities of silatropylium and silabenzyl cations and their isomers. Comparison with the carbon analogues tropylium and benzyl cations
(1996)High-level ab initio calculations on silatropylium (1-Si) and silabenzyl (2-Si) cations and seven of their low-lying isomers (3-8), as well as on their carbon analogues, tropylium (1-C) and benzyl (2-C) cations, are reported. ...
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Article
The remarkable effect of oxygen on the N2 selectivity of water catalytic denitrification by hydrogen
(2007)The selective catalytic reduction of nitrates (NO3-) in pure water toward N2 formation by the use of gaseous H2 and in the presence of O2 (air) at 1 atm total pressure and 25°C has been investigated over Pd-Cu supported ...
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Conference Object
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Article
Remote functionalization of C60 with enantiomerically pure cyclo-[2]-malonate tethers bearing C12 and C14 spacers: Synthetic access to bisadducts of C60 with the inherently chiral trans-3 addition pattern
(2013)In this Article, we describe the synthesis of two optically pure diols bearing a 1,2-diol moiety masked as an isopropylidene acetal group and long alkyl chains comprised of 12 and 14 carbon atoms, respectively. The synthetic ...
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Article
Removal of 241Am from Aqueous Solutions by Adsorption on Sponge Gourd Biochar
(MDPI, 2023)Luffa cylindrica biomass was converted to biochar and the removal of 241Am by pristine and oxidized biochar fibers was investigated in laboratory and environmental water samples. This species has the added advantage of a ...
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Conference Object