Chemistry: Sequential proton transfer through water bridges in acid-base reactions

Omar F. Mohammed; Dina Pines; Jens Dreyer; Ehud Pines; Erik T.J. Nibbering

doi:10.1126/science.1117756

Chemistry: Sequential proton transfer through water bridges in acid-base reactions

Omar F. Mohammed
, Dina Pines
, Jens Dreyer
, Ehud Pines
, Erik T.J. Nibbering

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

495 Scopus citations

Abstract

The proton transfer mechanism between aqueous Brønsted 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^-.

Original language	English
Pages (from-to)	83-86
Number of pages	4
Journal	Science
Volume	310
Issue number	5745
DOIs	https://doi.org/10.1126/science.1117756
State	Published - 7 Oct 2005

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@article{7fbf23700ad04a2abe3af709a14caab5,

title = "Chemistry: Sequential proton transfer through water bridges in acid-base reactions",

abstract = "The proton transfer mechanism between aqueous Br{\o}nsted 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-.",

author = "Mohammed, \{Omar F.\} and Dina Pines and Jens Dreyer and Ehud Pines and Nibbering, \{Erik T.J.\}",

year = "2005",

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doi = "10.1126/science.1117756",

language = "English",

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journal = "Science",

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TY - JOUR

T1 - Chemistry

T2 - Sequential proton transfer through water bridges in acid-base reactions

AU - Mohammed, Omar F.

AU - Pines, Dina

AU - Dreyer, Jens

AU - Pines, Ehud

AU - Nibbering, Erik T.J.

PY - 2005/10/7

Y1 - 2005/10/7

N2 - The proton transfer mechanism between aqueous Brønsted 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-.

AB - The proton transfer mechanism between aqueous Brønsted 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-.

UR - https://www.scopus.com/pages/publications/26444519205

U2 - 10.1126/science.1117756

DO - 10.1126/science.1117756

M3 - Article

AN - SCOPUS:26444519205

SN - 0036-8075

VL - 310

SP - 83

EP - 86

JO - Science

JF - Science

IS - 5745

ER -

Chemistry: Sequential proton transfer through water bridges in acid-base reactions

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