M. Massol

Synthèses et décomposition d'organométhoxygermanes et organométhoxyhalogénogermanes: Nouvelle méthode d'obtention de derivés organiques du germanium bivalent

Abstract The organomethoxy- and organomethoxyhalogermanes R2(MeO)GeH, R(MeO)GeH2, R(MeO)2GeH and R(MeO)(X)GeH (R = alkyl or phenyl) are synthesized by direct reaction at low temperature of sodium or lithium methoxides with the organohalogermanes R2(X)GeH, R(X)GeH2 and R(X)2GeH and by “chlorinemethoxy” exchange reactions between the same halohydrides and various methoxyorganogermanes. The instability of the organomethoxygermanes with GeH and GeO bonds lead to their decomposition with formation of divalent species of germanium and methanol. The “germylenes” 1 were characterized by condensation on the insaturated systems of 1,3-dienes and also by insertion into some σ-bonds.

Oxametallacycloalcanes : V. Synthese de sila-2, germa-2 et stanna-2 oxa-1 cyclopentanes par deshydrocondensation intramoleculaire d'hydrures silicies, germanies ou stanniques γ-hydroxyles

Abstract The γ-hydroxymetal hydrides OH (M = Si, Ge, Sn) were synthesized by reduction of γ-acetoxychloro- or γ-hydroxychloro-silanes, -germanes and -stannanes. These derivatives with MH bonds lead, by cyclisation at room- or higher temperatures, with or without catalyst, depending on the nature of the metal, to various oxametallacyclopentanes. The cyclisation proceeds by intramolecular dehydrocondensation between MH and OH bonds. These dehydrocondensation reactions are analysed and discussed according to the polarity of the MH bonds. Intramolecular addition of the MH bond into the unsaturated carboncarbon bonds of the corresponding non-cyclic compounds is also an excellent way of preparing the same heterocycles. The IR and NMR analyses of all new compounds are given.

Intermédiaires organiques du germanium divalent I. Synthèse de germanes α ou β fonctionnels par insertion de germylenes sur les liaisons C-X de dérivés organiques halogénés

Abstract The organic derivatives of divalent germanium (germylenes) of the type: R(Cl)Ge:(R=alkyl, phenyl, chlorine) obtained by decomposition at room temperature of the methoxychlorohydrogermane R(Cl)(MeO)GeH, were condensed on various organic halo derivatives. The insertion of the germylenes on the halogen-carbon bond of β-ethylenic halo-compounds, α-haloketo derivatives, acid chloride or α-haloethers, leads to the formation of functionally substituted α or β organopolyhalogermanes some of which can not be prepared by other ways. These insertion derivatives can be characterized by NMR and IR spectroscopy, as well as by chemical route. In some cases, the functional germanes isolated by reduction or alkylation of the insertion products have been synthesized independently by new chemicals ways.

SPECTROSCOPIC AND X-RAY STRUCTURAL STUDY OF THE COPPER(II) COMPLEX WITH SCHIFF BASE BETWEEN PYRIDOXAL AND BENZYLAMINE

Abstract Bis(N-benzylpyridoxaldiminato) copper(II) has been prepared and studied in solution and solid state. The complex crystallizes in the monoclinic space group C2h 5 – P21/a in a cell of a = .9561(9), b = 16.605(8), c = 17.561(2) A and β = 104.14(l). Based on 3684 unique reflections, the structure was refined by fullmatrix least-squares techniques to a conventional agreement factor (on F) of R = 0.045. Each ligand is bidentate through the phenolic oxygen and the imino nitrogen atoms, leading to a tetrahedrally distorted square planar environment about the copper atom. The dihedral angle between the two chelating moieties is 35.31°. The two benzyl groups are, surprisingly, in a cis position with respect to the mean plane of the molecule. In solution, the ESR data are consistent with a distorted square planar structure around Cu. Under particular conditions two sets of ESR signal are observed, suggesting the occurrence of two species.

Spectres de vibration de composés organiques de la colonne IVB IV. Dérivés oxygenés du germanium: Cycliques (oxa-1-germa-2-cyclopentanes et oxa-1-germa-2-cyclopentenes) et linéaires (monoalcoxytriéthylgermaniums et dialcoxydiéthylgermaniums)

Summary The IR and Raman spectra of four 1-oxa-2-germacyclopentanes, four 1-oxa-2-germacyclopentenes, two monoalkoxytriethylgermaniums, three dialkoxydiethylgermaniums and hexaethyldigermoxane have been examined in the 3600–100 cm −1 region. Assignments are discussed for the characteristic vibrations of these derivatives. Some specific bands of cyclic compounds of germanium are identified.

Nouveaux 1-oxa-2-germacycloalcanes et 1-oxa-2-germacycloalcenes II. Analyse structurale et réactivité chimique

Abstract The 1-oxa-2-germacyclopentanes and 1-oxa-2-germacyclopentenes previously synthesized have been analysed by IR and NMR spectroscopy. On the basis of these analyses a half chair conformation can be assigned to the substituted 1-oxa-2-germacyclpentanes. Cleavage of the germaniumoxygen bond of these heterocycles by some polar reagents confirm their structure. Various ring enlargement reactions by insertion of carbonyl derivatives lead to 1,3-dioxa-4-germepanes.

Mécanisme et stéréochimie des réaction d'addition des alcoyl- et alcoylhalogénogermanes sur le chlorure de propargyle

Abstract The organogermanium hydrides and halohydrides R 3 GeH, R 2 (Cl)GeH, R(Cl) 2 GeH and Cl 3 GeH react with propargyl chloride according to three competitive reactions of the GeH bond: addition on the triple bond giving several ethylenic isomers of the gemanium group; reduction of propargyl chloride to propyne and condensation/elimination with formation of a β-acetylenic organogermanium compound and release of HCl. The corresponding percentages of the different reactions are highly variable depending on the hydrides and the experimental conditions. They allow to study the mechanism and the stereochemistry of the addition, and to follow the variation of the polarity of the GeH bond as a function of the electronic effects of the substituents bonded to germanium.

Spectres de vibration de composes organiques des elements de la colonne IVB : VI. Comparaison des frequences de vibration observees sur des derives oxygenes cyclopentaniques et cyclopenteniques du silicium, du germanium et de l'etain et comparaison de leur basicite☆

Abstract The characteristic vibrations in IR and Raman spectra of 1-oxa-2-sila- (2-germa- or 2-stanna-)cyclopentanes and 1-oxa-2-germa- (or 2-stanna-)-3-cyclopentenes are compared. The basicity of the oxygen of these compounds is determined by IR measurements.

Spectrométrie de masse d'hétérocycles des éléments du groupe IV : IV. Expulsion de fragments neūtres et migrations dans les spectres de masse de germacyclopentènes

Abstract The mass spectra of some germacyclopentenes with different substituents on Ge have been examined, and information has been obtained on fragmentation processes leading to the expulsion of neutral molecules and to hydrogen or phenyl migration.

Spectres de vibration de composes organiques des elements de la colonne IVB : V. Derives cycliques oxygenes du silicium et de l'etain: Oxa-1 sila-2 cyclopentanes, oxa-1 stanna-2 cyclopentanes et cyclopentenes☆

Abstract Infrared and Raman spectra of two 1-oxa-2-stannacyclopentanes, three 1-oxa-2-stannacyclopentenes and three 1-oxa-2-silacyclopentanes have been examined in the 3600—100 cm−1 region. Assignments of the main bands observed are discussed.