Search results for " aldehydes"

showing 9 items of 9 documents

Sunlight-induced functionalisation reactions of heteroaromatic bases with aldehydes in the presence of TiO2: A hypothesis on the mechanism

2007

In previous studies we reported a new photocatalytic system involving polycrystalline TiO2 for the selective functionalisation of heteroaromatic bases with ethers and amides. In order to extend the applications of this new reaction and to better understand the mechanism involved, we have examined aromatic and aliphatic aldehydes as acyl radical sources for the nucleophilic addition to protonated N-heteroarenes in acetonitrile as the solvent and TiO2/H2O2 as the photocatalytic system. Acyl radicals may undergo decarbonylation to yield the corresponding alkyl radicals. Acyl/alkyl derivative ratios depend on the nature of the aldehydes, and present a different distribution from that obtained i…

Settore CHIM/03 - Chimica Generale e Inorganicachemistry.chemical_classificationAldehydesNucleophilic additionGeneral Chemical EngineeringRadicalDecarbonylationHeterocyclic basesGeneral Physics and AstronomyGeneral ChemistryPhotochemistryRedoxProduct distributionSunlight-induced reactions; TiO2; Heterocyclic bases; AldehydesAdductchemistryPhotocatalysisTiO2Sunlight-induced reactionsAlkylJournal of Photochemistry and Photobiology A: Chemistry
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Formaldehyde and total aldehydes in indoor air of public environments by voltammetry

2014

The proposed method involves active sampling, where a sampling pump is used to pull air through a solution and voltammetric analysis of the obtained solutions. No interferences have been observed. In addition, very little sample preparation is required. Analyses were performed in 19 indoor stations and one in outdoor. Measurements were carried out on University environments: Museum of Chemistry, Zoological Museum, libraries, laboratories, corridors, meeting rooms, photocopying room, machine shop and terrace. Formaldehyde concentrations in analyzed samples ranged from 2.6 to 85 μg m-3 (median = 32 μg m-3), while the sum of others aldehydes ranged from 2 to 25 μg m-3 (median =2.4 μg m-3). In …

voltammetryFormaldehydelibrariesmuseumaldehydesindoorSettore CHIM/12 - Chimica Dell'Ambiente E Dei Beni CulturaliFormaldehyde aldehydes indoor libraries museum voltammetry
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TiO2 Nanomaterials Used as Photocatalysts for Selective Heterogeneous Syntheses of Alcohols to Aldehydes in Water

2011

photocatalysis TiO2 organic synthesis aldehydes
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Supported Organocatalysts as a Powerful Tool in Organic Synthesis

2010

no abstract

chemistry.chemical_compoundAldol reactionchemistryOrganocatalysisOrganocatalysisAldol reactionPhase transfer catalysisOrganic chemistryOrganic synthesisα--selenenylation of aldehydesPrimary amine catalysis
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Photocatalytic process intensification by coupling with pervaporation

2011

The integration of photocatalysis with a membrane separation process, in particular pervaporation, permits the recovery of valuable intermediate compounds (aromatic aldehydes) while they are produced avoiding their further degradation in the reactive ambient. In this way the yield and the conversion are enhanced. The coupling of the two processes is straightforward and the integration is complete even maintaining pervaporation and photocatalysis in two separate apparatuses provided that the process stream is continuously recycled at a sufficiently high flow rate. Additional advantages are: higher degree of purification of the aldehyde in the powder-free product stream, semicontinuous produc…

Settore ING-IND/24 - Principi Di Ingegneria ChimicaChromatographyChemistrySettore ING-IND/25 - Impianti ChimiciAROMATIC ALDEHYDEPROCESS INTENSIFICATIONGeneral ChemistryCatalysisSeparation processVolumetric flow rateMembrane technologyPhotocatalysis Pervaporation Process ntensification Aromatic aldehydes Green chemistryChemical engineeringPERVAPORATIONYield (chemistry)Scientific methodPhotocatalysisDegradation (geology)PervaporationSettore CHIM/07 - Fondamenti Chimici Delle TecnologiePHOTOCATALYSISGREEN CHEMISTRY
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Green Production of Aldehydes from Alcohols by Heterogeneous Photocatalysis

2010

photocatalysis TiO2 aldehydes alcohols green production
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Nanostructured rutile TiO2 for selective photocatalytic oxidation of aromatic alcohols to aldehydes in water

2008

WOS: 000253100100022

chemistry.chemical_classificationSettore ING-IND/24 - Principi Di Ingegneria ChimicaChemistryGeneral ChemistryBiochemistryAldehydeCatalysisCrystallinityColloid and Surface ChemistryTiO2 Rutile Selectice photocatalytic oxidation Aromatic Alcohol Aromatic AldehydesRutilePhotocatalysisOrganic chemistrySelectivity
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Physico-chemical properties and sensory profile of durum wheat Dittaino PDO (Protected Designation of Origin) bread and quality of re-milled semolina…

2018

To help future quality checks, we characterized the physico-chemical and sensory properties of Dittaino bread, a sourdough-based durum wheat bread recently awarded with Protected Designation of Origin mark, along with the quality features of re-milled semolina used for its production. Semolina was checked for Falling Number (533–644 s), protein content (12.0–12.3 g/100 g d.m.), gluten content (9.7–10.5 g/100 g d.m.), yellow index (18.0–21.0), water absorption (59.3–62.3 g/100 g), farinograph dough stability (171–327 s), softening index (46–66 B.U.), alveograph W (193 × 10−4–223 × 10−4 J) and P/L (2.2–2.7). Accordingly, bread crumb was yellow, moderately hard (16.4–27.1 N) and chewy (88.2–10…

0301 basic medicineAbsorption of waterChemical PhenomenaRe-milled semolinaFurfuralHexanalAnalytical Chemistry03 medical and health scienceschemistry.chemical_compound0404 agricultural biotechnologyPentanolsDurum wheat bread; Quality control; Re-milled semolina; Sensory profile; Texture; Volatile compounds; Aldehydes; Chemical Phenomena; Pentanols; Bread; Triticum; Analytical Chemistry; Food ScienceFood scienceTextureAromaTriticumFarinographchemistry.chemical_classificationAldehydes030109 nutrition & dieteticsbiologyChemistryMedicine (all)Durum wheat breadSensory profileQuality control04 agricultural and veterinary sciencesGeneral MedicineSettore AGR/15 - Scienze E Tecnologie AlimentariBreadbiology.organism_classification040401 food scienceFalling NumberGlutenOdorVolatile compoundsVolatile compoundFood ScienceFood chemistry
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Sunlight-induced reactions of some heterocyclic bases with ethers in the presence of TiO2. A green route for the synthesis of heterocyclic aldehydes

2005

Settore CHIM/03 - Chimica Generale e InorganicaheterocyclesethersaldehydesTiO2sunlightPhotocatalysisPhotocatalysis; TiO2; sunlight; ethers; heterocycles; aldehydes;
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