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The article "Chemical Reactions in Supercritical
Carbon Dioxide"; (Wai, C. M.; Hunt, F.; Ji, M.; Chen, X.
J. Chem. Educ. 1998, 75, 1641-1645) should be corrected
as follows:
On page 1641 under the section
Hydrogenation and Hydroformylation, the first paragraph should appear
as shown below with corrections in boldface.
The work by Jessop et al. was mistakenly cited as
by Leitner et al. in the article. We apologize for the mistake.
Hydrogenation and Hydroformylation
High concentrations of
CO2 in the supercritical fluid phase can be advantageous for chemical reactions that
incorporate CO2. For example, in conventional synthesis,
hydrogenation of CO2 to formic acid is rendered thermodynamically
favorable by the addition of a base in an organic solvent.
This reaction is highly efficient in
scCO2 (Scheme I). The hydrogenation of
CO2 to formic acid using an organic
rhodium catalyst in dimethyl sulphoxide in a pressurized system
was investigated by Graf and Leitner
(11). Efficient production of formic acid in a supercritical mixture of
CO2 and H2, containing a trimethylphosphine complex of
RuII as a catalyst precursor, was reported by
Jessop et al. (12). The use of a
scCO2 phase, in which hydrogen can be dissolved with
a much higher concentration, leads to a very high initial
rate of reactionup to 1,400 moles of formic acid per mole
of catalyst per hour. The rate of the same reaction under
identical conditions in liquid organic solvents is lower by an
order of magnitude (12).
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