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Showing 1 to 20 of 83 for “"cyclopentadienyl"”.
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Cyclopentadienyl ruthenium chalcogenides
The interaction of transition metal complexes with H$\sb2$S, SH$\sp{-}$ and S$\sbsp{2}{2-}$ ligands is of interest because of their chemical relevance to metal sulfide hydrodesulfurization (HDS) catalysts. Ruthenium sulfur complexes are of interest because of the favorable catalytic properties of …
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The synthesis and stereodynamics of cyclopentadienyl ruthenium chalcogenide clusters
A diamagnetic salt of the (MeC$\sb5$H$\sb4)\sb4$Ru$\sb4$S$\sb4\sp{2+}$ cluster cation was obtained by oxidation of (MeC$\sb5$H$\sb4)\sb4$Ru$\sb4$S$\sb4$ with ((MeC$\sb5$H$\sb4)\sb2$Fe) PF$\sb6$. Variable temperature $\sp1$H NMR measurements showed that (MeC$\sb5$H$\sb4)\sb4$Ru$\sb4$S$\sb4\sp{2+}$ …
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Bulky cyclopentadienyl chromium complexes as ethene trimerisation catalyst precursors
… A stable Fe(II) model complex, bis-tetraphenylcyclopentadienyl iron, was prepared and cyclic voltametry conducted on it, to investigate the effect of phenyl substituents on a Cp ligand in the reduction I oxidation potential of the iron(II) centre. This study showed that phenyl rings on a …
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New Materials Based on Metallodithiolenes, Fullerenes, and Cyclopentadienyl Iron Complexes
… methods to functionalize a metal cluster through cyclopentadienyl (Cp) ligands. The cluster, $\rm Cp\sb4Fe\sb4(CO)\sb4,$ is prepared from the thermolysis of xylene solutions of $\rm Cp\sb2Fe\sb2(CO)\sb4$ and PPh$\sb3$ to yield primarily $\rm Cp\sb4Fe\sb4(CO)\sb4$ together with smaller amounts of …
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Metallkomplexe chinolylsubstituierter Cyclopentadienyl-Liganden : Synthese und Katalyse sowie Bildung heterobimetallischer Komplexe
… beschäftigt sich mit dem neuen (8-Chinolyl)cyclopentadienyl-Liganden. Durch die starre Geometrie des Chinolylgerüsts ist die für eine Stickstoff-Metall-Koordination im Komplex nötige Geometrie im Liganden schon vorgebildet. Die Synthese des Liganden gelingt entweder durch …
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Cyclopentadienyl ruthenium sulfide carbonyls and thiophene activation by iron and rhodium
The desulfurization and reduction of the sulfur-containing organic compounds in petroleum products is the objective of catalytic hydrodesulfurization (HDS), one of the largest applications of transition-metal catalysis. However, the specific mechanism for the process is not well understood. This …
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Synthesis and Characterization of Cyclopentadienyl Transition Metal Complexes Bearing Tetrafluoropyridyl Substituents
Three new tetrafluoropyridyl-substituted cyclopentadienes were synthesized. Reactions of pentafluoropyridine (C5F5N) with sodium cyclopentadienide (NaCp) in THF with excess NaH present afforded mixtures of (4-tetrafluoropyridyl)cyclopentadiene (1), 1,3-bis(tetrafluoropyridylcyclopentadiene) (2), …
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Halfsandwich tungsten complexes with a silanol-functionalized cyclopentadienyl ligand : synthesis and reactivity
… have been silanol-functionalized at the cyclopentadienyl ligand. The stability and the condensation behavior have been investigated. Thus, it was shown that these complexes are stable enough for isolation but they are reactiv enough for time-effective condensation reactions with diverse …
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Microwave-assisted Synthesis of Modified Cyclopentadienyl Iridium and Rhodium Chloro-bridged Dimers
The present work describes the design and synthesis of a series of dimers [(η5 - ring)MCl]2(μ2 -Cl)2, (where (η5 -ring)MCl = (η5 -Me4C5R)Rh(III)Cl or (η5 -Me4C5R)Ir(III)Cl). Iridium and rhodium dimeric complexes were synthesized via a microwave reaction and directly compared through single-crystal …
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The characterization and chemistry of {\it mono\/}- and {\it bis\/}-cyclopentadienyl titanium thiolates.
The reactions of Cp$\rm\sb2TiCl\sb2$ with the dithiols, HS(CH$\sb2)\sb{\rm n}$SH (n = 2, 3) in the presence of imidazole proceed with formation of imidazole$\cdot$HCl affording relatively insoluble titanocene dithiolate derivatives 2.1 and 2.2 respectively. Alternatively, 2.2 can be prepared by the …
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Steric and Electronic Effects Induced by Ancillary Ligand Substitutions on Cyclopentadienyl Osmium Complexes
To understand these variances, the molecular geometries of several osmium(II) and osmium(IV) complexes were investigated. (C5H5)Os(dmpm)Br reacts with NaOMe in refluxing methanol to afford the monohydride compound (C5H5)Os(dmpm)H, which can be protonated with HBF 4·Et2O to afford …
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Incorporation of Polar Comonomers Into High Density Polyethylene With a Cyclopentadienyl-Amido Titanium Catalyst
The purpose of this research was to synthesize the constrained geometry catalyst Ti[(C5Me4)SiMe2(tBuN)]Cl2 (1) with MAO as a cocatalyst for ethylene homopolymerization and copolymerizations with 1-TMSO-alkenes to produce a copolymer with polar functionality. Three 1-alkenols of varying length were …
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Exploring the Chemistry of Cyclopentadienyl-Cobalt-Cyclobutadiene (CpCoCb) Complexes and Synthesis of Side-Chain CpCoCb Polymers
… Organometallic polymers containing cyclopentadienyl-cobalt-cyclobutadiene (CpCoCb) have been targeted since early 1990’s due to their isoelectronic nature (cf. ferrocene) with three major groups working in this area. The early CpCoCb containing polymers were prepared by alkyne …
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Early transition metal complexes of carbene donors linked to cyclopentadienyl ring analogues or amidine/amidinate moieties
The new indenyl-functionalised NHC potassium salt, 1-[3-(4, 7-dimethylindenylpropyl]-3-<br/>(2,6-diisopropylphenyl)imidazol-2-ylidenepotassium, has been synthesised. Complexes of<br/>titanium, zirconium and chromium containing this ligand and the two carbon bridge …
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Development of Receptor-Targeted Imaging Agents: Integrated Gallium Complexes and Conjugated Cyclopentadienyl Tricarbonyl Rhenium and Technetium Complexes
… and utilized in the preparation of several cyclopentadienyltricarbonyl rhenium phenyl-tropanes. N-[4-Oxo-4-cyclopentadienyltricarbonyl rhenium butyl]-2beta-carbomethoxy-[3beta-(4-iodophenyl)] tropane was tested for affinity to the dopamine transporter in rat brain tissue homogenate as a …
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Synthesis, structures and studies of organoiron compounds
… of 3.7 kcal/mole was determined for the (η⁵-cyclopentadienyl) iron (II) dicarbonyl group by variable temperature ¹H NMR spectroscopic studies on cis-4-phenyl-1-(η⁵-cyclopentadienyl) iron (II) dicarbonyl cyclohexane. This is the first determination of the A value of a group with a transition …
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Part I. Synthesis and thermolysis of cyclopentadienyl and pentamethylcyclopentadienyl molybdenum dioxo alkoxides. Part II. Structural characterization of polysilicate intermediates formed during sol-gel polymerization
Part I. The molybdenum(VI) dioxo alkoxides ($\eta\sp5$-$C\sb5$H$\sb5$)MoO$\sb2$(OR) (R=CH$\sb2$CH$\sb3$, CH(CH$\sb3)\sb2$) and ($\eta\sp5$-C$\sb5$(CH$\sb3)\sb5$) MoO$\sb2$(OR) (R=CH$\sb3$, CH$\sb2$CH$\sb3$, CH(CH$\sb3)\sb2$) have been prepared and characterized. Single crystal X-ray diffraction …
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Small Molecule Rhenium Carbonyl Complexes: Model Integrated-Design Technetium Estrogen Receptor Ligands for Tumor Imaging
… synthetic route to a pair of acyl-substituted cyclopentadienyl complexes, along with their alkyl analogs, has been developed. A modification of the cyclopentadienyl motif introduces a hydroxyl-substituted 2-pyridinylmethyl group onto the central ring. The inclusion of the pyridine moiety allows …
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