Search results for "RIZ"

showing 10 items of 9613 documents

Ionic Liquids in Biphasic Ethylene Polymerisation

2011

Over the past several years there has been a considerable increase in the interest of ionic liquids as versatile reaction media for a wide variety of synthetic processes. The popularity of ionic liquids has been related primarily to their unique physical and chemical properties, which can be tailored by the judicious selection of cations and anions. These properties make it possible to use ionic liquids as solvents for many organic, inorganic, and organometallic compounds, including catalysts and co-catalysts, for various types of reactions. In particular, the polar but weakly coordinating character of ionic liquids enables them to be applied as mediums in catalysis, to immobilize various k…

chemistry.chemical_compoundchemistryChemical engineeringPolymerizationIonic liquidHomogeneous catalysisSolubilityMetalloceneMiscibilityCatalysisGroup 2 organometallic chemistry
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The Chemistry of the [1,2,3]Triazolo[1,5-a]pyridines: An Update

2010

Publisher Summary This chapter discusses the recent advancement in the chemistry of [1,2,3] triazolo[1,5-a]pyridines. It describes new discoveries in the physical properties and theoretical chemistry, focusing on synthesis of [1,2,3]triazolo[1,5-a]pyridine system, synthesis of novel aryltriazolopyridines, chiral ligands from [1,2,3]triazolo[1,5-a]pyridines, pyridylcarbene formation from triazolopyridines, ring-chain isomerization on [1,2,3]triazolo[1,5-a]pyridines, and novel pyridylcarbonylpyridines. All triazolopyridines have interesting ligand properties to form polynuclear complexes with different metal ions. X-ray single-crystal studies, magnetic, photo-magnetic, and colorimetric measur…

chemistry.chemical_compoundchemistryComputational chemistryCubaneStereochemistryLigandIntramolecular forcePyridineCardiovascular agentTheoretical chemistryAntiferromagnetismIsomerization
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Revision of Na 2 A1Σ+u state molecular constants by polarization labeling spectroscopy

1997

ABSTRACT. This paper contains the analysis of the A1 of Na2 based on the data obtained from thepolarization labeling spectroscopy experiment on the A' —X' transition. A set of Dunham coefficients is derived, which describes the A state in the wide range of v and J 126) quantum numbers and reproduces the positions of unperturbed rotational lines in the A-X band system towithinO.1 cm'.1. INTRODUCTION.We report' new analysis of the A' state based on the data obtained from polarization labelingspectroscopy (PLS) experiment"2, based on V-type optical—optical double resonance scheme, on the 1 : ' ; band system of sodium dimer. The diatomic alkali molecules, with their simple electronic configurat…

chemistry.chemical_compoundchemistryDimerAnalytical chemistryMoleculeElectron configurationAtomic physicsQuantum numberSpectroscopyPolarization (waves)Alkali metalDiatomic moleculeSPIE Proceedings
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1988

Terminaison d'un polystyrene lineaire telechelique avec des anions aux deux extremites a l'aide d'un agent de terminaison bifonctionnel et une haute dilution

chemistry.chemical_compoundchemistryLinear polymerPolymerization reactorPolymer chemistryPolystyreneDie Makromolekulare Chemie, Rapid Communications
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ChemInform Abstract: Poly(alkylidenamines) Dendrimers as Scaffolds for the Preparation of Low-Generation Ruthenium Based Metallodendrimers

2011

The aim of this article is to highlight the use of nitrile-functionalized poly(alkylidenamines) dendrimers as building blocks for the preparation of low-generation ruthenium based cationic metallodendrimers having in view potential biomedical applications. Air-stable poly(alkylidenamines) nitrile dendrimers, peripherally functionalized with the ruthenium moieties [Ru(η5-C5H5)(PPh3)2]+ or [RuCl(dppe)2]+, have been prepared, characterized and are being studied for their anticancer activity. The followed strategy is based on the biological advantages associated with low-generation dendrimers, the known activity of ruthenium compounds as anticancer drugs and the stability of these dendrimers at…

chemistry.chemical_compoundchemistryNitrileDendrimerCationic polymerizationchemistry.chemical_elementGeneral MedicineRuthenium CompoundsCombinatorial chemistryRutheniumChemInform
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Mononuclear heterocyclic rearrangements 5. Kinetic Investigation of the behaviour of (e)- and (z)-phenylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadia…

1980

The kinetic behaviour of the geometrical isomers I-E and I-Z of the title compound in the presence of piperidine in benzene has been investigated. The kinetic results suggest that I-Z rearranges directly into 2,5-diphenyl-4-benzoylamino-1,2,3-triazole (II), whereas I-E probably rearranges only through the intermediate I-Z formed by isomerization. All the reactions studied are piperidine-catalyzed.

chemistry.chemical_compoundchemistryOrganic ChemistryOxadiazolePiperidinePhotochemistryKinetic energyBenzeneMedicinal chemistryIsomerizationCis–trans isomerismJournal of Heterocyclic Chemistry
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On the low-lying singlet excited states of styrene: a theoretical contribution

2000

The present contribution analyses the trans–cis photoisomerization mechanism of ethene and styrene on the singlet manifold. Within the framework of multiconfigurational second-order perturbation theory (CASPT2), the extended multistate approach (MS-CASPT2) is found to be flexible enough to describe energy hypersurfaces adiabatically. For ethene, torsion about the CC bond towards a perpendicular structure leads to a situation where the energy difference between the ground and the lowest excited state is still too large (2.5 eV) for efficient radiationless decay. However, the energy gap decreases to 0.4 eV when one of the methylene moieties is, in addition, pyramidalized from the twisted stru…

chemistry.chemical_compoundchemistryPhotoisomerizationBand gapExcited stateGeneral Physics and AstronomyTorsion (mechanics)Singlet statePhysical and Theoretical ChemistryAtomic physicsMethylenePotential energyStyrenePhysical Chemistry Chemical Physics
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Polymere acroleine, 2. Mitt. Reaktionen und konstitution des disacryls

1956

Disacryl ist ein Polymerisationsprodukt des Acroleins, dessen Struktur bisher nicht geklart war. Obwohl es vollstandig unloslich ist, konnte es mit einer Reihe typischer Aldehydreagentien umgesetzt werden. Die Umsetzungsprodukte sinde in verschiedenen Losungsmitteln loslich; sie sind makromolekular. Es wird eine Strukturformel fur Disacryl vorgeschlagen. Disacryl is a polymerization product of acrolein and until now of unknown structure. In spite of its complete insolubility one can react it with typical aldehyd reagents. The reaction products are soluble in common solvents and are recognised as macromoleculare substances. A formula of disacryl is proposed.

chemistry.chemical_compoundchemistryPolymerizationAcroleinPolymer chemistryDie Makromolekulare Chemie
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Conductive Directly Fused Poly(Porphyrin) Coatings by Oxidative Chemical Vapour Deposition - From Single- to Triple-Fused

2019

chemistry.chemical_compoundchemistryPolymerizationChemical engineeringOrganic ChemistryChemical vapor depositionPhysical and Theoretical ChemistryThin filmPorphyrinElectrical conductorEuropean Journal of Organic Chemistry
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Organolanthanides as single component homogeneous catalysts for isoprenehex—1-ene co-polymerisation

1999

Abstract Bisallylansalanthanide complexes act as single component catalysts of diene polymerisation; from an equimolar mixture of isoprene and hex-1-ene, a co-polymer hex-1-ene/isoprene = 1:10 is obtained, this copolymer is essentially formed of 1,4- trans polyisoprene blocks separated by only one inserted hexyl group.

chemistry.chemical_compoundchemistryPolymerizationDienePolymer chemistryCopolymerHomogeneous catalysisGeneral ChemistryMetalloceneEne reactionIsopreneCatalysisComptes Rendus de l'Académie des Sciences - Series IIC - Chemistry
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