Annette Marchand

Spectres de vibration de composés organiques de la colonne IVB : II. Hexaalkyldigermoxanes, monoalcoxytrialkylgermaniums, dialcoxydialkylgermaniums, germaoxacycloalcanes. Comparaison avec leurs isologues siliciés and stanniques

Abstract The infrared spectra of two hexaalkyldigermoxanes R 3 GeOGeR 3 , fifteen alkoxytrialkylgermaniums R 3 GeOR′, twelve dialkoxydialkylgermaniums R 2 Ge(OR′) 2 and four alkylgermaoxacycloalkanes, have been examined in the 3600–2700 cm −1 and 1500–400 cm −1 regions. Some Raman spectra were also examined in the 3000–200 cm −1 region. Assignments are discussed for the characteristic stretching vibrations of GeC 3 , GeC 2 , GeOGe, GeOC and Ge(OC) 2 groups and for some vibrations of the methyl and butyl groups bound to germanium. Tentative correlation between the studied derivatives and isologous silicon and tin compounds is reported.

Étude comparative de la basicité de composés oxygénés du silicium, du germanium et de l'étain par spectrographie infrarouge

The following molecules were studied: R3MOMR3, R3MOR′ and R2M (OR′)2 where M = Si, Ge, Sn; R = CH3 or n-C4H9; R′ = CH3. Analysis of the infrared absorption spectra of solutions of methanol or pyrrole in these compounds yielded the frequency shifts Δv(OH) of methanol or Δv(NH) of pyrrole (in similar conditions) and the following classification with respect to the basicity of oxygen was established: dπpπ bonding between Si and O is responsible for the lower basic character of alcoxysilanes and disiloxanes. Such a bonding, probably, does not exist in oxygenated organotin compounds.

Étude par spectrographie infrarouge de composés organosiliciés : IV. Dialcoxydialkylsilanes et dialkylsiladioxacycloalcanes☆

Abstract The infrared spectra of dialkoxydialkylsilanes (A), alkylsilaoxacycloalkanes (B), dimethyl- and dibutyldichlorosilanes and hexabutylsiloxane have been examined in the 4000-2600 cm−1 and 1700-350 cm−1 regions. Assignments are discussed for the characteristic vibrations of chains of (A) and (B) compounds and for some vibrations of the methyl and butyl groups bound to silicon. Some specific bands of silaoxacycloalkanes are identified.

Vibrational spectra of styrene and its seven deuterated vinylic isotopomers: Complete assignment of the spectra by valence force field calculations

Abstract Vibrational spectra of styrene and its seven deuterated vinylic isotopomers have been recorded. A normal coordinate calculation by a valence force field treatment has permitted a complete assignment of all bands observed for the eight molecules. These calculations have been applied to previously published data on phenyldeuterated styrenes and results are in fairly good agreement with experimental.

Etude structurale d'enoxysilanes : I. Attribution des spectres de vibration du trimethylsiloxyethylene, de ses homologues deuteries et des methoxytrimethylsilanes diversement deuteries. Discussion des conformations moleculaires de l'enoxysilane

Abstract The infrared and Raman spectra of six compounds (trimethylsiloxyethylene, (CH 3 ) 3 SiOCHCH 2 , methoxytrimethylsilane, (CH 3 ) 3 SiOCH 3 , and their deuterated derivatives: (CD 3 ) 3 SiOCHCH 2 , (CH 3 ) 3 SiOCDCD 2 , (CD 3 ) 3 SiOCH 3 , (CH 3 ) 3 SiOCD 3 have been analysed. The majority of the bands observed have been assigned, in particular those due to ν(SiO). The study of the vinyl compounds shows that the enoxysilane exists in two conformers, the major being the gauche and the minor the s-cis one.

Spectres de vibration de composés organiques de la colonne IVB : III. Dérivés aminés organostanniques: Hexaalkyldistannazane, aminotributylétains N-disubstitués et bis(dialkylamino)dibutylétains. Analyse des spectres et détermination du champ de forces de valence de C3SnN(CH3)2

Abstract The IR and Raman spectra of N -ethylhexabutyldistannazane [(n-C 4 H 9 ) 3 Sn] 2 NC 2 H 5 , of six aminotributyltin compounds (n-C 4 H 9 ) 3 SnN , where R and R′ are alkyl or phenyl groups, and of three bis(dialkylamino)dibutyltin compounds (n-C 4 H 9 ) 2 Sn(NR 2 ) 2 where R is an alkyl group, have been examined in the 3600–100 cm −1 region. Assignments were discussed for the characteristic vibrations of these derivatives. The valence force field of C 3 SnN(CH 3 ) 2 has been computed using the results for dimethyl ether (methyl groups) and triethylchlorotin (carbon bound to tin). Experimental and calculated frequencies are in good agreement.

Mise en evidence de la formation de R2MMR2 a partir de disila-1,2 et digerma-1,2 cyclohexenes-4

Abstract Intermediates with π-bonded Si or Ge are generated during gas phase pyrolysis of 1,2-disila- or 1,2-digerma-cyclohex-4-enes. Compounds such as R2MMR2 are successfully trapped by addition or [2 + 2] and [4 + 2] cycloadditions. These results were proved by mass spectrometry.

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.

Spectres de vibration de composes organiques des elements de la colonne IV B : XII - Organopolygermanes☆

Abstract An investigation and interpretation is presented of the infra-red and Raman vibrational spectra of sixteen organic compounds with a GeGe bond. Some compounds of these series were specifically synthesized for this study. An assignment can be given to most observed bands. Particular attention is given to the discussion of the position of vibration frequencies υ(GeGe) and υ(GeH). From a comparison of the υ(SiH) and υ(GeH) frequencies it may be stated that the (p → d) π and (d-d) π interactions which can occur in some compounds are weaker in the case of digermanes than for disilanes.

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.