RESUMO
Using a surface science approach, the selectivity in the Ullmann cross-coupling of aryl halides on Cu(111) has been understood and controlled. The binding strength of the reactants and repulsion between them dictates which organometallic intermediates form, and hence the product distribution. Cross coupling can be maximized at low reactant concentrations.
RESUMO
The autocatalytic decomposition of tartaric acid on Cu(111) exhibits unique kinetics, which are linked to a hexagonal surface structure adopted at high coverage. The chirality imposed on the surface by tartaric acid throughout the explosion process is presented, and the hexagonal structure shows promise as a chiral template for enantiospecific surface chemistry.
RESUMO
On surfaces vicinal to Cu{111}, l-aspartic acid (l-Asp) adsorption causes steps to facet enantiospecifically into {310}R and {320}S steps. l-Asp has its highest heat of adsortion on surfaces that naturally expose the {310}R or {320}S steps but decomposes preferentially on the {310}R steps.
RESUMO
The Ullmann coupling of bromobenzene to biphenyl on Co nanoparticles proceeds below room temperature via an intermediate in which phenyl groups are bound directly to metallic Co. A similar surface-bound benzyl intermediate is observed for coupling of benzylbromide to bibenzyl on Co.
RESUMO
Using scanning tunnelling microscopy, we have visualized the segregation of carbon monoxide and hydrogen, the two reactants in Fischer-Tropsch synthesis, on cobalt nanoparticles at catalytically relevant coverages. Density functional theory was used to interrogate the relevant energetics.