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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6892
pubmed:dateCreated
2002-6-27
pubmed:abstractText
Compared to other ions, protons (H(+)) and hydroxide ions (OH(-)) exhibit anomalously high mobilities in aqueous solutions. On a qualitative level, this behaviour has long been explained by 'structural diffusion' the continuous interconversion between hydration complexes driven by fluctuations in the solvation shell of the hydrated ions. Detailed investigations have led to a clear understanding of the proton transport mechanism at the molecular level. In contrast, hydroxide ion mobility in basic solutions has received far less attention, even though bases and base catalysis play important roles in many organic and biochemical reactions and in the chemical industry. The reason for this may be attributed to the century-old notion that a hydrated OH(-) can be regarded as a water molecule missing a proton, and that the transport mechanism of such a 'proton hole' can be inferred from that of an excess proton by simply reversing hydrogen bond polarities. However, recent studies have identified OH(-) hydration complexes that bear little structural similarity to proton hydration complexes. Here we report the solution structures and transport mechanisms of hydrated hydroxide, which we obtained from first-principles computer simulations that explicitly treat quantum and thermal fluctuations of all nuclei. We find that the transport mechanism, which differs significantly from the proton hole picture, involves an interplay between the previously identified hydration complexes and is strongly influenced by nuclear quantum effects.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jun
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
417
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
925-9
pubmed:dateRevised
2003-11-3
pubmed:year
2002
pubmed:articleTitle
The nature and transport mechanism of hydrated hydroxide ions in aqueous solution.
pubmed:affiliation
Department of Chemistry and Courant Institute of Mathematical Sciences, New York University, 4 Washington Place, New York, New York 10003, USA. mark.tuckerman@nyu.edu
pubmed:publicationType
Journal Article