Search results for "HYDROLYSIS"

showing 10 items of 632 documents

Solution Chemistry of Element 106:  Theoretical Predictions of Hydrolysis of Group 6 Cations Mo, W, and Sg

2001

Fully relativistic molecular density-functional calculations of the electronic structure of hydrated and hydrolyzed complexes have been performed for the group 6 elements Mo, W, and element 106, Sg. By use of the electronic density distribution data, relative values of the free energy changes and constants of hydrolysis reactions were defined. The results show hydrolysis of the cationic species with the formation of neutral molecules to decrease in the order Mo > W > Sg, which is in agreement with experiments for Mo, W, and Sg. For the further hydrolysis process with the formation of anionic species, the trend is reversed:  Mo > Sg > W. A decisive energetic factor in the hydrolysis process …

Inorganic ChemistryHydrolysisChemistryGroup (periodic table)Inorganic chemistryCationic polymerizationPhysical chemistryMoleculeSolution chemistryElectronic structurePhysical and Theoretical ChemistryElectronic densityInorganic Chemistry
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The hydrolysis of Me2SnIV and Me3SnIV moieties monitored through 119Sn Mössbauer spectroscopy

1991

Abstract The 119 Sn Mossbauer parameters δ, isomer shift, and Δ E , nuclear quadrupole splitting, have been determined in frozen aqueous solutions of Me 2 Sn IV and Me 3 Sn IV moieties at varying pH. The resulting functions n versus pH (where n is the average number of protons released per mole of the organotin aquocation) agree satisfactorily with functions from potentiometry. The structures of the aquocations, as well as of the hydroxides, and of the mono-hydroxo complex [Me 2 Sn(OH)(OH 2 ) n ] + , are correlated to the Δ E exp data by point-charge model calculations.

Inorganic ChemistryHydrolysisReaction mechanismAqueous solutionChemistryMössbauer spectroscopyInorganic chemistryMaterials ChemistryQuadrupole splittingPhysical and Theoretical ChemistryInorganica Chimica Acta
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Analyzing the uniqueness of the rate constants calculated from complex kinetic systems: A study of the hydrolysis of ciclohexanecarbonitriles

1999

Inorganic ChemistryHydrolysisReaction rate constantChemistryOrganic ChemistryThermodynamicsUniquenessPhysical and Theoretical ChemistryKinetic energyBiochemistryInternational Journal of Chemical Kinetics
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Interaction of Zn(II) and Cd(II) with Large Polyazacycloalkanes in dmso/H2O (80:20 vol./vol.). A potentiometric Study.

1990

Abstract A potentiometric study on the interaction at 25 °C and 0.15 mol dm −3 between large polyazacycloalkanes of the series [3 k ]aneN k and Zn(II) and Cd(II) ions in dmso:H 2 O (80:20 vol./vol.) is reported. The protonation behavior of the free macrocycles and coordination trends are compared with those previously observed in aqueous solution. The main features observed in the mixed solvent are: similar protonation behavior of the free polyamines, greater tendency to form binuclear and protonated complexes and a lower tendency to bear hydrolytic reactions.

Inorganic ChemistrySolventHydrolysisAqueous solutionChemistryInorganic chemistryPotentiometric titrationMaterials ChemistryProtonationPhysical and Theoretical ChemistryChemical equilibriumMedicinal chemistryIon
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Novel enantiomerically pure 2-amino-1,4-diols from chiral 4-hydroxymethyl-5-iodo-1,3-oxazin-2-ones

2004

Abstract Reduction of (4 S ,5 S ,6 S )-4-hydroxymethyl-5-iodo-6-methyl-1,3-oxazin-2-one 2a and (4 S ,5 S ,6 R )-4-hydroxymethyl-5-iodo-6-phenyl-1,3-oxazin-2-one 2b with tributyltin hydride in ethanol afforded 1,3-oxazin-2-one 3a and 1,3-oxazolidin-2-one 4b , respectively. Hydrolysis of 3a and 4b under basic conditions led to enantiomerically pure aminodiols 1a and 1b . Reduction of 2b in refluxing toluene led to the unexpected bicyclic tetrahydrofuro[3 a , d ]-1,3-oxazolidin-2-one 5 as the sole product.

Inorganic Chemistrychemistry.chemical_compoundHydrolysisEthanolchemistryBicyclic moleculeOrganic ChemistryOrganic chemistryHydroxymethylTributyltin hydridePhysical and Theoretical ChemistryTolueneCatalysisTetrahedron: Asymmetry
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Aqueous solution chemistry of alkyltin(IV) compounds for speciation studies in biological fluids and natural waters

2012

Abstract Organotin(IV) cations behave as Lewis acids of different strength depending on the charge, according to the following acidity scale: RSn3+ > R2Sn2+ > R3Sn+. For this reason they can react with Lewis bases containing –O, –N, –S donor groups to form complex species of different stability. Complex formation of organotin(IV) moieties with a great number of inorganic and organic ligands in aqueous solution is reviewed here in the light of their environmental and biological impact. To this end, complex species formation was considered in different ionic media and at different ionic strengths, with reference to the composition of natural waters and biological fluids. In particular, the in…

Inorganic and organic ligandAqueous solutionSpeciationInorganic chemistryEnthalpyIonic bondingPhosphateHydrolysiMedicinal chemistryChloridePolyelectrolyteSequestration ability of different ligandInorganic Chemistrychemistry.chemical_compoundHydrolysischemistryAlkyltin(IV) complexeMaterials ChemistrymedicineAqueous solutionSettore CHIM/01 - Chimica AnaliticaLewis acids and basesPhysical and Theoretical Chemistrymedicine.drugCoordination Chemistry Reviews
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Sequestering ability of some chelating agents towards methylmercury(II).

2013

A study on the interactions between CH3Hg+ and some S, N and O donor ligands (2-mercaptopropanoic acid (thiolactic acid (H2 TLA)), 3-mercaptopropanoic acid (H2 MPA), 2-mercaptosuccinic acid (thiomalic acid (H3 TMA)), d,l-penicillamine (H2 PSH), l-cysteine (H2 CYS), glutathione (H3 GSH), N,N′-bis(3-aminopropyl)-1-4-diaminobutane (spermine (SPER)), 1,2,3,4,5,6-benzenehexacarboxylic acid (mellitic acid (H6 MLT)) and ethylenediaminetetraacetic acid (H4 EDTA)) is reported. The speciation models in aqueous solution and the possible structures of the complexes formed are discussed on the basis of potentiometric, calorimetric, UV spectrophotometric and electrospray mass spectrometric results. For t…

Inorganic chemistryElectrospray ionisation mass spectrometry (ESI-MS)Ethylenediaminetetraacetic acidCalorimetryBiochemistrySequestering ability of S N and O donor ligandAnalytical Chemistrychemistry.chemical_compoundHydrolysisSettore CHIM/01 - Chimica AnaliticaChelationMellitic acidThiomalic acidEnvironmental Restoration and RemediationChelating AgentsThiolactic acidAqueous solutionMolecular StructureLigandMethylmercury(II) cationMethylmercury CompoundsKineticschemistryMethylmercury(II) cation; Sequestering ability of S; N and O donor ligands; UV–spectrophotometry; Electrospray ionisation mass spectrometry (ESI-MS); PotentiometryPotentiometryEnvironmental PollutantsUV–spectrophotometryNuclear chemistryAnalytical and bioanalytical chemistry
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Synthesis and spectral studies ofN-2-pyridinylcarbonyl-2-pyridinecarxoximidate copper(II) complexes

1987

Dimeric and polymeric copper(II) complexes containing BPCA (N-2-pyridinylcarbonyl-2-pyridinecarboximidate), having general formulae Cu(BPCA)X·nH2O (X=Cl, Br, NCS, NCO, N3, or CN) and Cu2(BPCA)2-X·nH2O [X=oxalate anion (OX), chloranilate anion (CA) or the dianion of 2,5-dihydroxy-1,4-benzoquinone (DHBQ)] have been synthesized by the copper(II)-assisted hydrolysis of 2, 4, 6-tris(2-pyridyl)-1, 3, 5-triazine. Spectroscopic results indicate five-coordinate, approximately square-pyramidal, geometry around the copper(II) ion. Half-field absorption in the ΔMs=±2 region of the X-band e.p.r. powder spectra has been observed for the dimeric species.

Inorganic chemistryMetals and AlloysOxalate anionchemistry.chemical_elementCopperSpectral lineIonCatalysisInorganic ChemistryHydrolysischemistry.chemical_compoundCrystallographychemistryMaterials ChemistryAbsorption (chemistry)Organometallic chemistryTransition Metal Chemistry
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Confirmation of Fenthion Metabolites in Oranges by IT-MS and QqTOF-MS

2007

14 pages, 4 figures, 4 tables.-- PMID: 18020315 [PubMed].-- Printed version published Dec 15, 2007.

InsecticidesSulfoneElectrosprayFenoxon sulfoxideMass spectrometryMass SpectrometryAnalytical ChemistrySulfonechemistry.chemical_compoundSample preparationSulfonesPesticidesOrganophophorous pesticide fenthionChemical ionizationChromatographyFenthionHydrolysisSulfoxideFenoxon sulfoneSulfoxideFenthionchemistrySulfoxidesCholinesterase InhibitorsIon trapFood AnalysisCitrus sinensisAnalytical Chemistry
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Interaction of antibodies to proteinase 3 (classic anti-neutrophil cytoplasmic antibody) with human renal tubular epithelial cells: impact on signali…

2002

Abstract Among the anti-neutrophil cytoplasmic Abs (ANCA), those targeting proteinase 3 (PR3) have a high sensitivity and specificity for Wegener’s granulomatosis (WG). A pathogenetic role for these autoantibodies has been proposed due to their capacity of activating neutrophils in vitro. Recently, PR3 was also detected in human renal tubular epithelial cells (TEC). In the present study, the effect of murine monoclonal anti-PR3 Abs (anti-PR3) and purified c-ANCA targeting PR3 from WG serum on isolated human renal tubular cell signaling and inflammatory mediator release was characterized. Priming of TEC with TNF-α resulted in surface expression of PR3, as quantified in immunofluorescence stu…

Intracellular Fluidmedicine.medical_specialtyMyeloblastinImmunologyImmunofluorescencePhosphatidylinositolsAutoantigensDinoprostoneFlow cytometryAntibodies Antineutrophil CytoplasmicAntigen-Antibody ReactionsThromboxane A2Proteinase 3SuperoxidesInternal medicinemedicineCyclic AMPImmunology and AllergyHumanscardiovascular diseasesCells CulturedArachidonic Acidmedicine.diagnostic_testbiologyHydrolysisImmune SeraCell MembraneSerine EndopeptidasesAntibodies MonoclonalEpithelial CellsLipid signalingIn vitroCell biologyEndocrinologyKidney Tubulesbiology.proteinCyclooxygenaseSignal transductionInflammation MediatorsIntracellularSignal TransductionJournal of immunology (Baltimore, Md. : 1950)
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