149. The structure of “cyclopropane platinous chloride”

Adams, David M.; Chatt, J.; Guy, R. G.; Sheppard, N.

doi:10.1039/jr9610000738

Cited by 92 publications

(39 citation statements)

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“…For deuterium-labeled hydrocarbons, an isotope shift of 300-400 cm −1 should occur in the CHbending vibrations [34]. For complexes with weakened C=C bonds, the isotope shift is 90-150 cm −1 for deuteriumlabeled olefins [55,56], while the C=O-stretching vibration is not significantly shifted, i.e., it is only about 10-20 cm −1 [34,49]. If the adsorbed species have a carboxylate structure, the shift is expected to be about 20-30 cm −1 with 18 O present [49].…”

Section: Adsorption Of C 4 H 6 and C 4 D 6 On Promoted Ag Catalystsmentioning

confidence: 99%

Adsorption of 1,3-butadiene on supported and promoted silver catalysts

Müslehiddinoğlu

Vannice

2004

Journal of Catalysis

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Section: Adsorption Of C 4 H 6 and C 4 D 6 On Promoted Ag Catalystsmentioning

confidence: 99%

Adsorption of 1,3-butadiene on supported and promoted silver catalysts

Müslehiddinoğlu

Vannice

2004

Journal of Catalysis

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“…Metal‐olefin complexes are ubiquitous organometallic intermediates in catalysis, involved in processes such as the oxidation, the hydrogenation, the oligomerization or the polymerization of olefins . The nature of the olefin‐metal interaction is typically described by the Dewar−Chatt−Duncanson model, which invokes a σ ‐donating interaction from the olefin π (C=C) orbital to an empty d‐orbital on the metal with the correct symmetry and π ‐back‐donation of a filled metal d‐orbital to the π *(C=C) orbital as the main stabilizing factors ( Figure ,a ) . This bonding leads to a lengthening of the C=C bond and an increase of p‐character in the carbon atoms (sp 2 →sp 3 ).…”

Section: Introductionmentioning

confidence: 99%

Metal Olefin Complexes: Revisiting theDewar−Chatt−DuncansonModel and Deriving Reactivity Patterns from Carbon‐13 NMR Chemical Shift

Gordon

Andersen

Copéret

2019

Helvetica Chimica Acta

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† Dedicated to the memory of our dear friend, colleague, and mentor Richard A. Andersen. This work emanates from many discussions regarding the teaching of organometallic chemistry at the graduate and undergraduate level at UC Berkeley, ETH Zürich, and the University of Tokyo.Metal olefin complexes that are ubiquitous intermediates in catalysis are investigated by a detailed analysis of their 13 C-NMR chemical shift tensors. This analysis allows evidencing specific electronic features, namely the olefin-to-metal σ-donation and the metal-to-olefin π-backdonation as proposed in the DewarÀ ChattÀ Duncanson model. Apart from these interactions, the chemical shift tensor analysis reveals an additional ligand-to-metal πdonation of the olefin σ(C=C) orbital in systems with suitably oriented vacant d-orbitals. This interaction which is not accounted for in the DewarÀ ChattÀ Duncanson model explains the reactivity of this type of metal olefin complexes towards oxidative cyclization (olefin insertion) and protonolysis.Keywords: olefin complexes, NMR spectroscopy, density functional calculations, chemical shift analysis, frontier molecular orbitals. the DewarÀ ChattÀ Duncanson model of olefins binding to metals. b) Two Lewis structures used to represent ethylene as a neutral (left) and a di-anionic (right) ligand.

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“…Although catalytic C -C bond activation is at the forefront of innovative research, stoichiometric C -C bond activation has been reported [39] . These examples rely largely on relief of ring strain [40] , attainment of aromaticity [41] , or intramolecular addition in which the C -C bond is forced into close proximity to the metal [42] .…”

Section: Catalysis With Nickelmentioning

confidence: 99%

Cobalt and Nickel Catalyzed Reactions Involving CH and CN Activation Reactions

Becker

Jones

2010

Catalysis Without Precious Metals

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IntroductionHomogeneous transition metal catalyzed reactions have been very well studied over the past 50 years. The metal complexes used to accomplish these reactions have typically included noble transition metals or fi rst row metals. Due to the cost and pathogenicity of these noble metals, the development of new catalytic routes using non -precious metals is an active area of research. In this chapter, a review of the use of selected cobalt and nickel species towards catalytic reactions analogous to those seen with noble metals is presented. Catalysis with CobaltTransition metal catalyzed hetero -annulation provides a useful and convenient tool for the construction of N -heterocycles [1] . Quinolines are of special interest in that they display attractive applications in pharmaceuticals and are synthetic building blocks [2,3] . Catalytic processes employing palladium [4 -6] , rhodium [7 -9] , ruthenium [10 -14] , and iron [15] have been studied and developed to synthesize quinoline skeletons. There are fi ve common methods used to prepare substituted quinolines: the Skraup reaction [16] , the Doebner -Von Miller reaction [17] , the Conrad -Limpach reaction [18] , the Friedlaender reaction [19,20] , and the Pfi tzinger reaction [21,22] . All fi ve of the reactions require environmentally unfriendly acids or bases, high temperatures, or harsh conditions. Quinoline yields are usually low due to numerous side reactions. Even though much work has been done to fi nd catalytic routes to quinolines, the use of non -precious metals remains an active area of research.Recently, Jones et al. have published work on the conversion of diallylanilines and arylimines to quinolines [23,24] . It was found that N -allylaniline, when heated in the presence of 10 mol% Co 2 (CO) 8 and 1 atm of CO at 85 ° C, leads to the selective formation of 2 -ethyl -3 -methylquinoline (Equation (6.1) ). Aniline and propene 6 Catalysis Without Precious Metals. Edited by R. Morris Bullock

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149. The structure of “cyclopropane platinous chloride”

Cited by 92 publications

References 0 publications

Adsorption of 1,3-butadiene on supported and promoted silver catalysts

Adsorption of 1,3-butadiene on supported and promoted silver catalysts

Metal Olefin Complexes: Revisiting theDewar−Chatt−DuncansonModel and Deriving Reactivity Patterns from Carbon‐13 NMR Chemical Shift

Cobalt and Nickel Catalyzed Reactions Involving CH and CN Activation Reactions

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