Search results for "methane"

showing 10 items of 1763 documents

Studies in organic mass spectrometry. Part 25. Benzyl ion formation in chemical ionisation (methane or isobutane) of someortho-alkylhetero-substitute…

2000

The behaviour of some ortho-alkylhetero-substituted diphenylcarbinols, including deuterium labelled derivatives, under chemical ionisation (methane or isobutane) conditions has been investigated. It has been determined that ortho-alkylhetero diphenylmethyl cations formed by water elimination from the protonated molecule undergo consecutive rearrangements which afford benzyl (or tropylium) ions previously observed for ortho-substituted diphenylcarbenium ions generated by electron ionisation. This reaction also occurs under low-energy collision conditions. Copyright © 2000 John Wiley & Sons, Ltd.

ChemistryOrganic ChemistryInorganic chemistryProtonationPhotochemistryMass spectrometryMethaneAnalytical ChemistryIonchemistry.chemical_compoundIonizationIsobutaneMoleculeSpectroscopySpectroscopyRapid Communications in Mass Spectrometry
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ChemInform Abstract: A Convenient and General Synthesis of Alkanediyl Diphenols.

2010

ChemistryOrganic chemistryGeneral MedicineCondensation reactionDiphenylmethane derivativesChemInform
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ChemInform Abstract: Synthesis of Highly Functionalized 9,10-Phenanthrenequinones by Oxidative Coupling Using MoCl5.

2012

An efficient method to prepare functionalized 9,10-phenanthrenequinones including the natural cypripediquinone A (VIIIa) is reported.

ChemistryOxidative coupling of methaneGeneral MedicineCombinatorial chemistryChemInform
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Structural and spectroscopic study of the Br2...3-Br-pyridine complex by DFT calculations.

2007

Abstract The structure and the Raman vibrational spectrum of the complex Br 2 ⋯3-Br-pyridine are determined by DFT calculations using different parametrizations. The calculations are performed taking into account the effects of the dichloromethane as solvent by the CPCM method. A value of 39 kJ mol −1 for the formation enthalpy and of 1 kJ mol −1 for the formation free energy at room temperature in presence of the solvent is found. The predicted Raman spectrum is compared with the experimental one and the essential features of the spectrum are well reproduced by the B3LYP parametrization. The intensity changes of the bands when going from the free moieties to the complex are also generally …

ChemistryPyridinesEntropyEnthalpyMolecular ConformationVibrational spectrumBromineSpectrum Analysis RamanAtomic and Molecular Physics and OpticsAnalytical ChemistrySolventchemistry.chemical_compoundsymbols.namesakeModels ChemicalComputational chemistryPyridinesymbolsPhysical chemistrySolvent effectsRaman spectroscopyInstrumentationParametrizationSpectroscopyDichloromethaneSpectrochimica acta. Part A, Molecular and biomolecular spectroscopy
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Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane—A NEXAFS Study

2012

It is demonstrated that the near-edge X-ray absorption fine structure (NEXAFS) provides a powerful local probe of functional groups in novel charge transfer (CT) compounds and their electronic properties. Microcrystals of tetra-/hexamethoxypyrene as donors with the strong acceptor tetracyano-p-quinodimethane (TMP/HMP-TCNQ) were grown by vapor diffusion. The oxygen and nitrogen K-edge spectra are spectroscopic fingerprints of the functional groups in the donor and acceptor moieties, respectively. The orbital selectivity of the NEXAFS pre-edge resonances allows us to precisely elucidate the participation of specific orbitals in the charge transfer process. Upon complex formation, the intensit…

ChemistryResonanceGeneral ChemistryPhotochemistryBiochemistryAcceptorTetracyanoquinodimethaneCatalysisXANESSpectral linechemistry.chemical_compoundPartial chargeColloid and Surface ChemistryAtomic orbitalSelectivityJournal of the American Chemical Society
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Baeyer−Villiger Oxidation with Potassium Peroxomonosulfate Supported on Acidic Silica Gel

2005

[reaction: see text] Potassium peroxomonosulfate deposited onto silica SiO2 x KHSO5 efficiently reacts with ketones in dichloromethane at room temperature to give the corresponding esters or lactones in quantitative yields. This method avoids hydrolysis of the reaction products. The Baeyer-Villiger reaction is catalyzed by potassium hydrogensulfate present in the supported reagent.

ChemistrySilica gelPotassiumOrganic Chemistrychemistry.chemical_elementGeneral MedicinePotassium peroxymonosulfateCatalysisBaeyer–Villiger oxidationchemistry.chemical_compoundHydrolysisReagentOrganic chemistryDichloromethaneThe Journal of Organic Chemistry
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cis-[Bis(diphenylphosphino)ethane-κ2P,P′]dichlororuthenium(II) dichloromethane disolvate

2006

The title compound, cis-[RuCl2(C26H24P2)2]·2CH2Cl2, was obtained as an unexpected product from our attempts to prepare new ruthenium molecular wires using organic bridging ligands. Three solvates and a solvent-free structure of the isomeric complex with the chloride anions in a trans geometry have already been reported, while the cis isomer has been described only in solution studies prior to this work.

ChemistryStereochemistrychemistry.chemical_elementGeneral Chemistry.Condensed Matter PhysicsChlorideMedicinal chemistryRutheniumchemistry.chemical_compoundFaculdade de Ciências Exatas e da EngenhariamedicineGeneral Materials ScienceCis–trans isomerismmedicine.drugDichloromethanecis-[Bis(diphenylphosphino)ethane-j2PP000]dichlororuthenium(II) dichloromethane disolvate
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cis-Diazido[bis(diphenylphosphino)methane-κ2P,P′]ruthenium(II) dichloromethane 0.42-solvate

2006

Submitted by António Freitas (amsf@uma.pt) on 2019-06-13T13:44:22Z No. of bitstreams: 1 cis-Diazidobis(diphenylphosphino)methane-j2PP000ruthenium(II) dichloromethane 0.42-solvateJoãoRodrigues.pdf: 167616 bytes, checksum: 2ba0b7a76027be3eda26ce11d43fec66 (MD5) Made available in DSpace on 2019-06-13T13:44:22Z (GMT). No. of bitstreams: 1 cis-Diazidobis(diphenylphosphino)methane-j2PP000ruthenium(II) dichloromethane 0.42-solvateJoãoRodrigues.pdf: 167616 bytes, checksum: 2ba0b7a76027be3eda26ce11d43fec66 (MD5) Previous issue date: 2006 info:eu-repo/semantics/publishedVersion

Chemistrychemistry.chemical_elementGeneral Chemistry.Condensed Matter PhysicsTriple bondMedicinal chemistrycis-Diazido[bis(diphenylphosphino)methane-j2PP000]ruthenium(II) dichloromethane 0.42-solvateMethaneRutheniumMetalchemistry.chemical_compoundFaculdade de Ciências Exatas e da Engenhariavisual_artvisual_art.visual_art_mediumOrganic chemistryGeneral Materials Science
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Optical, Electrochemical, and Catalytic Properties of the Unsaturated Host Pd3(dppm)3(CO)2+and Pd4(dppm)4(H)2+2Clusters: An Overview

2004

This paper presents an overview of the optical, photophysical, and photochemical properties including UV-visible and luminescence spectra in solution at 298 and 77 K, along with electrochemical, and catalytic behavior under reduction conditions (for both thermally and electrochemically assisted systems) of the tri- and tetranuclear Pd3(dppm)3(CO)2+ and Pd4(dppm)4(H)2+ 2 clusters (dppm=bis(diphenylphosphino)methane). This review is also complemented with relevant information about their syntheses, molecular and electronic structures supported from computer modeling, EHMO and DFT calculations, and their host-guest behavior with anions and neutral molecules, in relation with their observed rea…

Chemistrychemistry.chemical_elementNanochemistryGeneral ChemistryCondensed Matter PhysicsPhotochemistryElectrochemistryBiochemistryMethaneCatalysischemistry.chemical_compoundMoleculeGeneral Materials ScienceReactivity (chemistry)PlatinumPalladiumJournal of Cluster Science
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CCDC 249547: Experimental Crystal Structure Determination

2005

Related Article: M.Viciano, E.Mas-Marza, M.Poyatos, M.Sanau, R.H.Crabtree, E.Peris|2005|Angew.Chem.,Int.Ed.|44|444|doi:10.1002/anie.200461918

Chloro-(eta^4^-cyclo-15-octadiene)-hydrido-(bis(N-methyl-13-dihydridoimidazol-3-yl-2-ylidene)(ferrocenyl)methane)-iridium hexafluorophosphate monohydrateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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