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Dichloride Complex (dichloride + complex)

Distribution by Scientific Domains
Chemistry83%

Selected Abstracts

Palladium(II)-Phosphine Complexes Supported on Magnetic Nanoparticles: Filtration-Free, Recyclable Catalysts for Suzuki,Miyaura Cross-Coupling Reactions

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010
Sankaranarayanapillai Shylesh
Abstract An organic-inorganic hybrid heterogeneous nanocatalyst system was synthesized by covalent grafting a palladium dichloride complex of the type (L)2PdCl2 (L=trimethoxysilyl-functionalized triphenylphosphine) on silica-coated magnetic nanoparticles. It is a highly active and recyclable catalyst for the Suzuki,Miyaura cross-coupling reaction. The new catalyst can easily be separated from the reaction mixture by applying an external magnetic field and can be recycled many times without any loss of activity. [source]

20-Di­cyano­methyl­ene-5,8,11,14-tetraoxa-2,17-di­thia­bi­cyclo­[16.4.1]­tricosa-1(23),18,21-triene and its mercury(II) dichloride complex

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2000
Kanji Kubo
The structures of the title compound, C20H24N2O4S2, and its mercury(II) dichloride complex, dichloro{20-di­cyano­methyl­ene-5,8,11,14-tetraoxa-2,17-di­thia­bi­cyclo­[16.4.1]­tricosa-1(23),18,­21-tri­ene-,4O,,S17}mercury(II), [HgCl2(C20­H24­N2­O4­S2)], have been determined by X-ray crystallographic analyses. The mercury(II) dichloride complex has two independent mol­ecules of [HgCl2(C20H24N2O4S2)] in the lattice. The mercury(II) ion has pentagonal bipyramidal coordination which involves one S atom, four O atoms and two Cl, ions. [source]

1,3,6-Azadiphosphacycloheptanes: A novel type of heterocyclic diphosphines

HETEROATOM CHEMISTRY, Issue 2 2008
Andrey A. Karasik
The novel type of seven-membered cyclic diphosphines, namely 1,3,6-azadiphosphacycloheptanes, has been synthesized by condensation of 1,2-bis(phenylphosphino)ethane, formaldehyde, and primary amines (aniline, p -toluidine, benzylamine, and 5-aminoisophthalic acid) as a mixture of rac- and meso-stereoisomers. The structures of rac-stereoisomers of N -tolyl and N -(3,,5,-dicarboxyphenyl)-substituted diphosphines were investigated by X-ray crystal structure analyses. The stereoisomers of N -(3,,5,-dicarboxyphenyl)-substituted compound were separated at a preparative scale, and their platinum(II) dichloride complexes were obtained. The corresponding meso-isomer readily forms P,P -chelate complex with [PtCl2(cod)], whereas the rac-stereoisomer forms oligomeric complex. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:125,132, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20397 [source]

Ferrocenyl-Aryl Based trans -Chelating Diphosphine Ligands: Synthesis, Molecular Structure and Application in Enantioselective Hydrogenation

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010
Raffael Schuecker
Abstract Potentially trans -chelating diphosphine ligands based on a ferrocenyl-aryl backbone were synthesised in a four-step sequence and the molecular structures in the solid state of two representatives were determined by X-ray diffraction. High throughput screening of these ligands in rhodium-, ruthenium- and iridium-mediated hydrogenations of a variety of alkenes and ketones revealed that these ligands can deliver high enantioselectivity for alkenes (up to 98% ee) but are less selective when ketones are used as the substrates. The coordination behaviour of one ligand in its square planar palladium and platinum dichloride complexes was studied by 31P,NMR and only trans -chelated complexes, together with oligomeric by-products, were observed. Reaction with the (p -cymene)ruthenium dichloride dimer, [RuCl2(p -cymene)]2, resulted in a mixture of diastereomeric complexes. [source]

High-molar-mass polypropene with tunable elastic properties by hafnocene/borate catalysts

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2006
Tanja Seraidaris
Abstract Elastic polypropene has gained growing industrial and academic interest as a thermoplastic elastomer. In this study, "rac"- and "meso"-dimethylsilyl(3-benzylindenyl)(2-methylindenyl)hafnium dichloride complexes (Hfr and Hfm, respectively), activated with [NHMe2Ph][B(C6F5)4]/triisobutyl aluminum, were used in propene polymerization. Using these catalyst systems, we obtained polymers with high molar masses, up to 550 kg/mol, and moderate isotacticities between 34 and 52%. By varying the polymerization conditions, we could modify the polymer microstructure and molar mass. 13C NMR was used to calculate the polymer pentad sequence distributions. The crystalline parts of the polymers were analyzed with the differential scanning calorimetry successive self-nucleation and annealing (SSA) technique. The SSA thermograms revealed that Hfr produced polypropene with a more uniform lamellar structure than Hfm. The mechanical properties were tested with dynamic mechanical analysis creep-recovery tests. In the series, the polymers with the lowest isotacticities and therefore lowest crystallinities showed the best elastic properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4743,4751, 2006 [source]