Search results for "Benzene"

The role of theory level in prediction of benzene magnetic indexes of aromaticity is analysed and compared with calculated nuclear magnetic shieldings of 3 He used as NMR probe. Three closely related nucleus-independent chemical shift (NICS) based indexes were calculated for benzene at SCF-HF, MP2, and DFT levels of theory and the impact of basis set on these quantities was studied. The changes of benzene NICS(0), NICS(1), and NICS(1)zz parameters calculated using SCF-HF, MP2 and several density functionals were within 1 to 3 ppm. Similar deviations between magnetic indexes of aromaticity were observed for values calculated with selected basis sets. Only very small effect of polar solvent o…

NICS010304 chemical physicsHelium atomIsotropyAromaticityaromaticityGeneral Chemistry010402 general chemistryRing (chemistry)DFT01 natural sciencesMolecular physicsNMR0104 chemical sciencesbenzenechemistry.chemical_compoundchemistry0103 physical sciencesAtomPhysics::Atomic and Molecular ClustersPolarGeneral Materials SciencePhysics::Chemical PhysicsBenzeneBasis setMagnetic Resonance in Chemistry

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Local aromaticity in polyacenes manifested by individual proton and carbon shieldings: DFT mapping of aromaticity

2019

Exponential dependencies between locally calculated geometric and magnetic indexes of aromaticity, harmonic oscillator model of aromaticity (HOMA) and nucleus independent chemical shifts (NICS)(0), NICS(1) and NICS(1)zz, and the number of conjugated benzene rings in linear acenes, from benzene to decacene were observed at B3LYP/6-311+G** level of theory. Correlations between HOMA and NICS indexes showed exponential dependencies and were fitted with simple three-parameter function. Similar correlations between both indexes of aromaticity and proton and carbon nuclear isotropic shieldings of individual acene rings were observed. Contrary to proton data, the predicted 13 C nuclear isotropic sh…

NICSProtonchemistry.chemical_element010402 general chemistrypolyacenes01 natural sciencesMolecular physicschemistry.chemical_compoundPhysics::Atomic and Molecular ClustersHOMAGeneral Materials ScienceReactivity (chemistry)Physics::Chemical PhysicsBenzenenuclear shieldingAceneHarmonic oscillator010405 organic chemistrymolecular modelingChemical shiftAromaticityGeneral Chemistryaromaticity0104 chemical scienceschemistryCarbonMagnetic Resonance in Chemistry

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NMR Spectra of Some Chlorinated Diphenyliodonium Salts and Iodobenzenes

1996

NMR spectra databaseIodobenzenesChemistryProton NMROrganic chemistryGeneral Materials ScienceGeneral ChemistryCarbon-13 NMRMagnetic Resonance in Chemistry

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1971

The polymerisation of ethylene was carried out in the presence of (C5H5)2TiCl2/(C2H5)2AlCl in benzene (I) and of TiCl4/(C2H5)AlCl2 in chlorobenzene (II). In the initial state of the polymerisation with I oligomers with a narrow molecular weight distribution are formed. According to their IR and NMR spectra they were identified as predominantly saturated linear hydrocarbons. The effect of a substitution of the cyclopentadienyl rings by R = CH3 and C2H5 was studied as well as the influence of aging particularly on the molecular weight distribution. The catalytic system II yields predominantly unsaturated branched oligomers with broad molecular weight distribution. The ligand effect on the str…

NMR spectra databasechemistry.chemical_compoundEthylenechemistryCyclopentadienyl complexPolymerizationChlorobenzeneLigandPolymer chemistryMolar mass distributionBenzeneDie Makromolekulare Chemie

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CCDC 705757: Experimental Crystal Structure Determination

2010

Related Article: K.Salorinne, D.P.Weimann, C.A.Schalley, M.Nissinen|2009|Eur.J.Org.Chem.|2009|6151|doi:10.1002/ejoc.200900814

N^1^N^1^'N^1^''N^1^'''-((281420-tetraethyl-6121824-tetramethoxypentacyclo[19.3.1.1^37^.1^913^.1^1519^]octacosa-1(25)3(28)469(27)101215(26)16182123-dodecaene-4101622-tetrayl)tetrakis(oxyethane-21-diyl))tetrabenzene-12-diamine acetonitrile ethanol clathrateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates

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CCDC 809191: Experimental Crystal Structure Determination

2012

Related Article: J.T.Koivunen, L.Nissinen, J.Kapyla, J.Jokinen, M.Pihlavisto, A.Marjamaki, J.Heino, J.Huuskonen, O.T.Pentikainen|2011|J.Am.Chem.Soc.|133|14558|doi:10.1021/ja206086c

N^1^N^3^-bis(9-Oxo-9H-fluoren-2-yl)benzene-13-disulfonamideSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates

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Gold nanoparticle catalysis of the cis-trans isomerization of azobenzene

2013

Ablated, “pseudo-naked” gold nanoparticles (AuNPs) catalyze the cis–trans isomerization of substituted azobenzenes. para-Substitution was found to affect the rate of isomerization, suggesting the participation of AuNP-mediated electron transfer in the isomerization mechanism. Fil: Hallet Tapley, Geniece. University of Ottawa; Canadá Fil: D'Alfonso, Claudio. University of Ottawa; Canadá. Universita Di Roma; Italia Fil: Pacioni, Natalia Lorena. University of Ottawa; Canadá Fil: McTiernan, Cristopher D.. University of Ottawa; Canadá Fil: Gonzalez Bejar, Maria. University of Ottawa; Canadá. Universidad de Valencia; España Fil: Lanzalunga, Osvaldo. Universita Di Roma; Italia Fil: Alarcon, Emilio…

NanoparticleNANOCATALYSIS010402 general chemistryPhotochemistry01 natural sciencesCatalysisCatalysisElectron transferchemistry.chemical_compoundMaterials ChemistryGOLDISOMERIZATION010405 organic chemistryChemistryOtras Ciencias QuímicasCiencias QuímicasMetals and AlloysGeneral ChemistryCis trans isomerization0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsAZOBENZENESAzobenzeneColloidal goldCeramics and CompositesIsomerizationCIENCIAS NATURALES Y EXACTAS

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