Linked Life Data

18288835

Source:http://linkedlifedata.com/resource/pubmed/id/18288835

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2008-3-12
pubmed:abstractText
In solution, half-cell potentials are measured relative to those of other half cells, thereby establishing a ladder of thermochemical values that are referenced to the standard hydrogen electrode (SHE), which is arbitrarily assigned a value of exactly 0 V. Although there has been considerable interest in, and efforts toward, establishing an absolute electrochemical half-cell potential in solution, there is no general consensus regarding the best approach to obtain this value. Here, ion-electron recombination energies resulting from electron capture by gas-phase nanodrops containing individual [M(NH3)6]3+, M = Ru, Co, Os, Cr, and Ir, and Cu2+ ions are obtained from the number of water molecules that are lost from the reduced precursors. These experimental data combined with nanodrop solvation energies estimated from Born theory and solution-phase entropies estimated from limited experimental data provide absolute reduction energies for these redox couples in bulk aqueous solution. A key advantage of this approach is that solvent effects well past two solvent shells, that are difficult to model accurately, are included in these experimental measurements. By evaluating these data relative to known solution-phase reduction potentials, an absolute value for the SHE of 4.2 +/- 0.4 V versus a free electron is obtained. Although not achieved here, the uncertainty of this method could potentially be reduced to below 0.1 V, making this an attractive method for establishing an absolute electrochemical scale that bridges solution and gas-phase redox chemistry.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-12224965, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-12580620, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-14500975, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-15366993, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-15549929, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-16783766, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-16854031, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-17394314, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-17521917, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-17542579, http://linkedlifedata.com/resource/pubmed/commentcorrection/18288835-17778547
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
19
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3371-81
pubmed:dateRevised
2011-9-26
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Absolute standard hydrogen electrode potential measured by reduction of aqueous nanodrops in the gas phase.
pubmed:affiliation
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural