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Infra-red spectra of systems containing hydrogen-bonds; Spectres dans l'infrarouge de corps a liaison hydrogene

Abstract

A new theory of the infrared spectra of H-bonded systems is presented, which analyses the different stretching motions in an X-H...Y bond, and studies the validity of their separation. We attribute the structure in the spectra of H-bond stretching motions to the anharmonic coupling of the modes X-H...Y with the modes X-H...H. Starting with the hypothesis that the X-H...Y motion is harmonic, but depends parametrically upon the X...Y distance, and taking into account the interaction between different H-bonds, we have been able to simulate quantitatively (intensity and position) the I.R. spectra of species such as imidazole and acetic acid dimers, which are the experimentally best resolved spectra. The isotope effect (substitution of H by D) is explained quite naturally, and the experimental spectrum of deuterated species is simulated quantitatively, without introducing any other hypothesis; this fact gives us a positive test for the validity of our theory. We have extended those previous considerations to the case of H-bonded crystals, in view of a future reconstitution of their I.R. spectra. The physical meaning of our theory is quite different to most of the previously proposed theories, which have not been confirmed quantitatively, to the best of our knowledge. Those theories did  More>>
Authors:
Marechal, Y [1] 
  1. Commissariat a l'Energie Atomique, Grenoble (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1969
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-3683
Resource Relation:
Other Information: TH: These docteur es-sciences; PBD: 1969
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ACETIC ACID; CHEMICAL BONDS; EQUATIONS OF MOTION; HAMILTONIANS; HYDROGEN; IMIDAZOLES; INFRARED SPECTRA
OSTI ID:
20528713
Research Organizations:
CEA Grenoble, 38 (France); Grenoble-1 Univ., Faculte des Sciences, 38 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3683094979
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[113] pages
Announcement Date:
Dec 10, 2004

Citation Formats

Marechal, Y. Infra-red spectra of systems containing hydrogen-bonds; Spectres dans l'infrarouge de corps a liaison hydrogene. France: N. p., 1969. Web.
Marechal, Y. Infra-red spectra of systems containing hydrogen-bonds; Spectres dans l'infrarouge de corps a liaison hydrogene. France.
Marechal, Y. 1969. "Infra-red spectra of systems containing hydrogen-bonds; Spectres dans l'infrarouge de corps a liaison hydrogene." France.
@misc{etde_20528713,
title = {Infra-red spectra of systems containing hydrogen-bonds; Spectres dans l'infrarouge de corps a liaison hydrogene}
author = {Marechal, Y}
abstractNote = {A new theory of the infrared spectra of H-bonded systems is presented, which analyses the different stretching motions in an X-H...Y bond, and studies the validity of their separation. We attribute the structure in the spectra of H-bond stretching motions to the anharmonic coupling of the modes X-H...Y with the modes X-H...H. Starting with the hypothesis that the X-H...Y motion is harmonic, but depends parametrically upon the X...Y distance, and taking into account the interaction between different H-bonds, we have been able to simulate quantitatively (intensity and position) the I.R. spectra of species such as imidazole and acetic acid dimers, which are the experimentally best resolved spectra. The isotope effect (substitution of H by D) is explained quite naturally, and the experimental spectrum of deuterated species is simulated quantitatively, without introducing any other hypothesis; this fact gives us a positive test for the validity of our theory. We have extended those previous considerations to the case of H-bonded crystals, in view of a future reconstitution of their I.R. spectra. The physical meaning of our theory is quite different to most of the previously proposed theories, which have not been confirmed quantitatively, to the best of our knowledge. Those theories did not take into account the interactions between different H-bonds. Thus our quantitative simulation of complex spectra of imidazole and acetic acid, together with the correct prediction of the isotope effect, help us thinking that the proposed mechanism is responsible for the different stretching motions in H-bonded systems. (author) [French] Nous exposons une nouvelle theorie des spectres infra-rouge de la liaison hydrogene, basee sur l'analyse des mouvements d'elongation des atomes d'une liaison X-H...Y, et nous recherchons les conditions de la separabilite de ces differents mouvements. L'origine de la structure des spectres d'elongation de l'hydrogene est attribuee au couplage des modes du type X-H...Y et X-H...Y. En supposant que le mouvement X-H...Y est harmonique, mais depend parametriquement de la distance X...Y, et en tenant compte de l'interaction entre differentes liaisons hydrogene, nous pouvons reconstituer quantitativement les spectres des corps tels que l'imidazole et les dimeres d'acide acetique, qui forment les spectres les mieux resolus experimentalement. L'effet isotopique (remplacement de H par D) decoule tout naturellement de cette supposition, et le spectre experimental des corps deuteres est reconstitue quantitativement, sans aucune hypothese supplementaire, ce qui nous donne une confirmation independante de la validite de notre theorie. Nous etendons ces considerations au cas de cristaux a liaison hydrogene en vue d'une reconstitution future de leurs spectres infrarouge. Par sa signification physique, notre theorie s'oppose aux theories proposees anterieurement, qui ne tenaient pas compte de ce mecanisme de couplage ni de l'interaction entre liaisons hydrogene. Ces theories anterieures n'ont pas recu, a notre connaissance, de verification quantitative. Aussi notre reconstitution quantitative des spectres a structure complexe de l'imidazole et de l'acide acetique, ainsi que notre prevision correcte de l'effet isotopique, semblent indiquer que le mecanisme propose est le facteur principal qui intervient dans les differents mouvements d'elongation de la liaison hydrogene. (auteur)}
place = {France}
year = {1969}
month = {Jul}
}