Alkali metal additions to unsaturated systems

Kalyanaraman, V.; George, M. V.

doi:10.1016/s0022-328x(00)81738-6

Cited by 33 publications

(2 citation statements)

References 468 publications

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“…Alkali metals react with molecular hydrogen (H 2 ) at temperatures as low as 80 °C, but at a low temperature, the reaction is inhibited by the diffusion barrier caused by a crust of NaH that is formed on the Na metal . In the presence of multinuclear aromatics, many reductive addition reactions are possible, , including the heterolytic scission of hydrogen with the subsequent addition to the sodium–aromatic ion pair (eq ). The reaction of anthracene dissolved in decalin with sodium was performed at 150 °C under N 2 and H 2 atmospheres, separately.…”

Section: Results and Discussionmentioning

confidence: 99%

Sodium Conversion of Oilsands Bitumen-Derived Asphaltenes

Styles

Klerk

2016

Energy Fuels

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Alkali metals are strong electron donors and can form electron donor−acceptor ion pairs with multinuclear aromatics. Single electron donation converts the aromatic into a radial ion, and two electron donations convert the aromatic into a dianion. The anionic aromatic species are more susceptible to reductive addition reactions, such as hydrogen transfer from more hydrogen-rich molecules, such as employed in Birch reduction. The conversion of heavy oils in the presence of alkali metals is claimed to be capable of bulk desulfurization with little hydrogen consumption. In this work, the conversion of oilsands bitumen asphaltenes with sodium was investigated over the temperature range of 60−250 °C under an inert atmosphere to limit the contribution of thermal conversion. Control experiments conducted with asphaltenes without sodium revealed that the asphaltenes were reactive on their own, and the nature of products was affected by the phase behavior of the asphaltenes that gradually changed from a solid to liquid between 124 and 142 °C. When fluidity was limited, intermolecular hydrogen transfer was restricted; intramolecular hydrogen disproportionation and "in cage" intermolecular reactions resulted in the formation of more condensed and potentially more aromatic products. Sodium markedly affected the natural hydrogen transfer and disproportionation. Conversion of the asphaltenes with sodium did not result in an increased maltene yield, but the maltenes had a higher hydrogen/carbon ratio, less sulfur, and less nitrogen. Model compound reactions were employed to study the influence of the reaction atmosphere (N 2 or H 2 ) and hydrogen donor properties of the organic matrix. In the presence of H 2 , the formation and reaction of NaH appeared to influence selectivity and the reaction network. In the absence of H 2 , desulfurization of thiophenic compounds by sodium proceeded by hydrogenolysis and hydrogenation pathways, with the hydrogenolysis pathway being favored by the lack of hydrogen donor molecules. It was also found that hydrogenolysis of the carbon−carbon bond in the thiophenic ring of dibenzothiophene is reversible.

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Section: Results and Discussionmentioning

confidence: 99%

Sodium Conversion of Oilsands Bitumen-Derived Asphaltenes

Styles

Klerk

2016

Energy Fuels

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“…[29] More specifically, they result easily able of incorporating electrons giving rise to anionic species. [29] More specifically, they result easily able of incorporating electrons giving rise to anionic species.…”

Section: Marcel Dekker Inc • 270 Madison Avenue • New York Ny 10016mentioning

confidence: 99%

Hydrosolubilization of Large Aromatic Molecules: Facile Synthesis and Characterization of Water-Soluble Derivatives of Decacyclene

Arrais

Diana

2003

Synthetic Comm.

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Application of a mild-condition reductive/oxidative protocol to the large poorly-conjugated aromatic structure of decacyclene affords a water soluble oxygenated amphiphilic material which has been characterized and compared with the hydrocarbon precursor by means of solution 1 H NMR and solid-state 13 C CPMAS NMR, vibrational, electron, and mass spectroscopies. The nature of the different oxygenated moieties covalently attached to decacyclene framework is elucidated and the role of molecular O 2 in the oxidizing reaction path of reduced decacyclene is discussed.

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With Adducts of Conjugated Hydrocarbons in Donor Solvents

Grovenstein¹

1988

Inorganic Reactions and Methods

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Alkali metal additions to unsaturated systems

Cited by 33 publications

References 468 publications

Sodium Conversion of Oilsands Bitumen-Derived Asphaltenes

Sodium Conversion of Oilsands Bitumen-Derived Asphaltenes

Hydrosolubilization of Large Aromatic Molecules: Facile Synthesis and Characterization of Water-Soluble Derivatives of Decacyclene

With Adducts of Conjugated Hydrocarbons in Donor Solvents

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