Publication Date:
2005-10-08
Description:
The proton transfer mechanism between aqueous Bronsted acids and bases, forming an encounter pair, has been studied in real time with ultrafast infrared spectroscopy. The transient intermediacy of a hydrated proton, formed by ultrafast dissociation from an optically triggered photoacid proton donor ROH, is implicated by the appearance of an infrared absorption marker band before protonation of the base, B-. Thus, proton exchange between an acid and a base in aqueous solution is shown to proceed by a sequential, von Grotthuss-type, proton-hopping mechanism through water bridges. The spectra suggest a hydronium cation H3O+ structure for the intermediate, stabilized in the Eigen configuration in the ionic complex RO-...H3O+...B-.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mohammed, Omar F -- Pines, Dina -- Dreyer, Jens -- Pines, Ehud -- Nibbering, Erik T J -- New York, N.Y. -- Science. 2005 Oct 7;310(5745):83-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Born Institut fur Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16210532" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
