Jacques Maillols

Analyse vibrationnelle et structurale en série aliphatique insaturée: II. Spectres raman des acides fumarique et maléique en solution

Abstract The Raman spectra of fumaric and maleic acids in solution (H 2 O and D 2 O) have been studied from 250 to 4000 cm − . The analysis of the polarisation ratio of the observed lines has led us to establish that the fumaric acid molecule is planar (symmetry C 2h ) whereas the maleic acid is non-planar, this molecule belonging either to the C s group (the plane of symmetry being perpendicular to the C C double bond) or more probably to the C 2 group. An assignment of the observed lines as fundamentals is proposed.

Vibrational spectra in cyclopropane series—IV. Analysis of the i.r. absorption and Raman scattering of cyclopropyl bromide

Abstract The Raman spectra of cyclopropyl bromide are measured in substantia and the i.r. spectra both in the gaseous and liquid states. The simultaneous analysis of the rotational envelope of the absorption bands and of the degree of depolarization of the Raman bands lead to the assignment of the 21 fundamentals. This assignment is corroborated by that of the binary combinations and by a normal coordinate treatment. The cyclopropyl bromide fundamentals can be deduced from those of cyclopropane, the observed differences being due essentially to the mass effect and only partly to the chemical character of the substituent. The thermodynamic functions are calculated in a usual harmonic oscillator and rigid rotator approximation.

Vibrational spectra in cyclopropane series: II. Symmetry and conformation in the gas phase of the monomer and dimer of cyclopropanecarboxylic acid

Abstract Infrared and Raman spectra of gaseous cyclopropanecarboxylic acid (C 3 H 5 COOH and C 3 H 5 COOD) were measured from 250 to 4000 cm −1 . The bands were assigned respectively to the monomer and to an associate. The depolarization ratio measurement, the vib—rot envelope study and the detailed analysis of the v (CO) and v (CH) regions enabled the symmetry and the conformation of the molecular entities in equilibrium to be determined. The monomer belongs to the C s symmetry group and the conformation of its predominant fraction is trans/trans . The associate is a centrosymmetrical dimer ( C i symmetry) having (trans/cis) 2 conformation. Some features of the geometry of the pseudocycle are discussed.

Analyse vibrationnelle et structurale en série aliphatique insaturée: I. Étude des fumarate et maléate neutres de potassium

Abstract The Raman and infrared spectra of potassium maleate and fumarate in aqueous solutions have been studied from 100 to 3500 cm −1 . The analysis of the polarization ratio of the Raman lines allows us to corroborate the symmetries C 2v (maleate) and C 2h (fumarate) previously found for these two organic ions by other authors who had, however, studied a narrower spectral range. A more complete assignment concerning nearly all the fundamentals is proposed.

Vibrational spectra in cyclopropane series—III. Fundamental modes of cyclopropanecarboxylic acid monomer and of its -OD species

The i.r. and Raman spectra of cyclopropanecarboxylic acid CH2CH2CHCO2H and of its -OD species in the gas phase are obtained. The temperature shift of the equilibrium between rnonorner and dimer is used to identify the bands belonging to the monomer entity. The assignment of bands to the fundamental vibrations is based on the normal coordinate analysis, calculated correlation of fundamentals for the isotopically monosubstituted cyclopropanes, the use of the non-crossing rule, the application of Teller—Redlich product rule, the calculation of characteristics of vib—rot band envelopes and the measurement of depolarization ratios of Raman bands. The thermodynamic functions are calculated for the molecule considered as a rigid one in a usual harmonic oscillator approximation. The anharmonicity of the ν(OH) mode is also appreciated.

Etude vibrationnelle et structurale des acides carboxyliques hétérocycliques et de leurs dérivés—III. Spectres Raman et infrarouges du furanne 2-5 dicarboxylate de sodium

Abstract The Raman spectrum of sodium furan 2–5 dicarboxylate in aqueous solution has been studied in the 4000-250 cm −1 region. The i.r. spectra of this compound (solid and aqueous solution) have been investigated in the same spectral region. An assignment of the observed bands has been proposed. The analysis of the polarization ratio of the fundamental frequencies of the free furan 2–5 dicarboxylate ion and the comparison with the results by X-rays of the furan 2-5 dicarboxylic acid have enabled us to conclude that this ion may have the C s symmetry in aqueous solution.

Phase transition in non-ionic surfactant—water systems as studied by Raman spectrometry: Part I. Water—α-octyl-ω-hydroxypentakis (oxyethylene)

Abstract The Raman spectra of α-octyl-ω- hydroxypentakis (oxyethylene) (C8E5) in water—(C8E5) systems have been studied for various compositions and at various temperatures. Continuous changes of the spectra are observed in the isotropic phase, when varying the composition, which is maximum when approaching the hexagonal phase boundary. The transition between the isotropic and hexagonal phases brings about an important change in the ν(CH) region. A tentative interpretation of these results is given.

Étude physico-chimique du système ternaire polystyrène-benzène-butanol,: I. — Zone de coacervation et caractérisation des phases en équilibre

Le but du travail etant l’etude du mecanisme de la coacervation, nous nous proposons d’envisager et d’interpreter ce phenomene dans le cas particulier du systeme ternaire poly- styrene-benzene-butanol. Dans cet article, nous definissons pour ce systeme la zone de coacervation et caracterisons par leur composition ponderale les differentes phases en equilibre ; les diagrammes des phases sont etablis a 20 et 30 °C. En outre, l’interpretation du trace du reseau de droites de conjugaison permet de rattacher le processus de coacervation a celui d’une insolubilisation du polystyrene, la forte interaction entre le solvant et le non solvant provoquant l’exclusion du polymere.