55449-47-3

Upstream product

• 110-83-8 cyclohexene 
• 71-43-2 benzene 
• 1165952-91-9 cyclohexa-1,3-diene 
• 1165952-92-0 cyclohexa-1,4-diene 

Relevant academic research and scientific papers

Interaction of D(H) atoms with physisorbed benzene and (1,4)-dimethylcyclohexane: Hydrogenation and H abstraction

Benzene and (1,4)-dimethyl-cyclohexane monolayers were physisorbed on graphite covered Pt(111) surfaces. Exposure of benzene monolayers at 125 K to D atoms (1700 K) initially hydrogenates sp2 hybridized C atoms with a cross section of ca. 8 A2 producing C6H6D intermediates. Additional D atom reactions either transform this intermediate via a second hydrogenation reaction to cyclohexadiene-d2, C6H6D2, or restore benzene, C6H5D, via H abstraction. Once the aromaticity is broken, successive hydrogenation of the diene occurs rapidly generating the saturated cyclohexane-d6, C6H6D6. The C6H5D reaction product can undergo further H/D exchange reactions and, at any level of deuteration, the benzene species might get hydrogenated. Monolayers of the saturated hydrocarbon (1,4)-dimethyl-cyclohexane (DMCH) that are exposed to D atoms produce deuterated DMCH via successive abstraction/hydrogenation reactions. Thermal desorption mass spectra revealed that H atoms at the ring were exchanged with an apparent cross section of 1.7 A2. Methyl groups H atoms were exchanged much more slowly than ring H atoms. It was also observed that D exposed molecules/radicals exhibit a tendency to desorb from the surface, which is ascribed to the exothermicity of the reactions which lead to these species.

Catalytic Hydrogenation of Aromatic Hydrocarbons. Stereochemical Definition of the Catalytic Cycle for η3-C3H5Co(P(OCH3)3)3

The η3-C3H5Co(P(OCH3)3)3-catalyzed hydrogenations with D2of a series of unsaturated organic molecules, including cyclohexenes, cyclohexadienes, and arenes, have been investigated.Complete cis stereoselectivity was observed in the addition of deuterium to the unsaturated ring systems.When alkyl-substituted arenes were reduced with D2, the hydrogen atoms in the alkyl chains underwent H-D exchange as long as each successive carbon atom in the chain possessed at least one hydrogen atom.Hence, extensive H-D exchange occured in n-alkyl side chains while the tert-butyl side chain was deuterium free.When alkyl-substituted arenes were hydrogenated in the presence of olefins such as 1-hexene, a variety of isomeric alkylcyclohexenes and alkenylcyclohexanes were observed.The relative concentrations of these isomeric species provided information about the relative stabilities of the (olefin)cobalt species in the catalytic cycle.Further mechanistic information was obtained from other competitive reactions, i.e., hydrogenation reactions involving equimolar quantities of two different unsaturated molecules.The proposed initiation steps of the catalytic cycle have been revised on the basis of a study of η3-C8H13Co(P(OCH3)3)3 as a catalyst precursor.The cyclooctenyl-cobalt bond was cleaved by hydrogen early in the reaction, leaving the highly coordinately unsaturated hydride, HCo(P(OCH3)3)2, which is probably the true catalytic species.