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Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons

Conference:

Abstract

The systematic H/D substitution is a precious tool to obtain information on the dynamics of H-bonds. It is particularly useful in IR spectroscopy where H-bonds are at the origin of particularly intense and specific bands and where the particularly great value for the m{sub D}/m{sub H} ratio ensures strongly marked effects. In most H-bonded systems the effects of these substitutions are normal, in the sense that they are at the origin of bands having intensities, centers (of intensity) and widths smaller in D-bonds by a factor close to {radical}2 as compared to H-bonds. In some systems as carboxylic acid dimers, however, anomalous ratios of intensities are found upon such a substitution. Their origin is still obscure. Experimental results suggest that such anomalous ratios have much to do with the cyclic structure of these systems. It leads to stressing an important property of H-bonded cyclic structures which is that they seem necessary for having transfers of protons between molecules through H-bonds in a neutral aqueous medium (p{sub H}=7) at room temperature. The mechanism of such transfers of protons is still poorly known, but these transfers are now suspected to play a fundamental role in such widespread reactions as hydrolysis, peptide synthesis,  More>>
Authors:
Publication Date:
Dec 01, 1993
Product Type:
Conference
Report Number:
CEA-CONF-11595; CONF-9307157-
Reference Number:
SCA: 400202; PA: AIX-25:001861; EDB-94:014128; ERA-19:004643; NTS-94:014050; SN: 93001119665
Resource Relation:
Conference: Summer School on Isotopic Effects,Karpacz (Poland),13 Jul 1993; Other Information: PBD: 1993
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; HYDROGEN TRANSFER; ISOTOPE EFFECTS; CARBOXYLIC ACIDS; CHEMICAL BONDS; DEUTERIUM; HYDROGEN 1; INFRARED SPECTRA; 400202; ISOTOPE EFFECTS, ISOTOPE EXCHANGE, AND ISOTOPE SEPARATION
OSTI ID:
10109498
Research Organizations:
CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee
Country of Origin:
France
Language:
English
Other Identifying Numbers:
Other: ON: DE94608551; TRN: FR9303909001861
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
FRN
Size:
13 p.
Announcement Date:
Jun 30, 2005

Conference:

Citation Formats

Marechal, Y. Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons. France: N. p., 1993. Web.
Marechal, Y. Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons. France.
Marechal, Y. 1993. "Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons." France.
@misc{etde_10109498,
title = {Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons}
author = {Marechal, Y}
abstractNote = {The systematic H/D substitution is a precious tool to obtain information on the dynamics of H-bonds. It is particularly useful in IR spectroscopy where H-bonds are at the origin of particularly intense and specific bands and where the particularly great value for the m{sub D}/m{sub H} ratio ensures strongly marked effects. In most H-bonded systems the effects of these substitutions are normal, in the sense that they are at the origin of bands having intensities, centers (of intensity) and widths smaller in D-bonds by a factor close to {radical}2 as compared to H-bonds. In some systems as carboxylic acid dimers, however, anomalous ratios of intensities are found upon such a substitution. Their origin is still obscure. Experimental results suggest that such anomalous ratios have much to do with the cyclic structure of these systems. It leads to stressing an important property of H-bonded cyclic structures which is that they seem necessary for having transfers of protons between molecules through H-bonds in a neutral aqueous medium (p{sub H}=7) at room temperature. The mechanism of such transfers of protons is still poorly known, but these transfers are now suspected to play a fundamental role in such widespread reactions as hydrolysis, peptide synthesis, etc... which may make them soon appear as being a crucial basic mechanism for reactivity of aqueous systems, particularly biological systems.}
place = {France}
year = {1993}
month = {Dec}
}