42967-49-7Relevant academic research and scientific papers
Reaction de derives a liaison germanium-azote (germylamines, cyclogermazanes et germa-imines transitoires) avec la di-t-butyl-3,5-orthoquinone
Riviere-Baudet, M.,Riviere, P.,Khallaayoun, A.,Satge, J.,Rauzy, K.
, p. 77 - 94 (2007/10/02)
Several germanium-nitrogen compounds were treated with 3,5-di-t-butylorthoquinone (1).In the case of germylamines R3GeNMe2 (R = Et, Ph), 1,2 and 1,4 adducts were formed, as shown by 1H NMR spectroscopy.The thermally unstable 1,4 adduct, decomposes with nitrene elimination to give 2,2-dialkyl or 2,2-diaryl (6,8-di-t-butyl)-4,5-benzo-2-germa-1,3-dioxolane.The 1,2 adduct, through intermolecular redistribution, leads to digermyloxide (R3Ge)2O and a gem-diamine with partial regeneration of the starting quinone 1.These addition reactions proceed through a monoelectric transfer mechanism, with formation of a transient o-semiquinonic radical identified by ESR spectroscopy.This transient radical leads to O-germyl 3,5-di-t-butylcatechol by hydrogen abstraction from the solvent.The proposed mechanism explains the formation of the germylated compounds as well as the organic by-products.Similar reactions were observed between cyclodigermazanes and 1.The 1,4 cycloaddition generates germadioxolanes with nitrene expulsion, whereas the 1,2-cycloaddition leads to the germoxane and conjugated ketoimine, or diimine.The latter is a good trapping agent for the nitrene formed in the decomposition of the 1,4 adduct.Both the 1,4 and 1,2 cycloadduct decompositions imply transient germaimine formation.The same germaimine, formed at room temperature from intramolecular dehydrogenation of the hindered R2ClGeNHR' by 1,8-diazabicyclo-7-undecene) gives the same reaction products.
On Polygermanes, XVIII. Synthesis of the Multifunctional Digermanes Ph6-nGe2Cln (n = 2, 3, 4) and of Ph2GeCl2 under Pressure
Haeberle, Karl,Draeger, Martin
, p. 323 - 329 (2007/10/02)
Reaction of Ph6Ge2 with liquid HCl under pressure leads to di-, tri- and tetrachloro phenyldigermanes.The yield of higher chlorinated products increases with increasing pressure.The analogous reaction of Ph4Ge yields Ph2GeCl2 quantitatively.The Ge-Ge bond is most unstable in the case of Ph3Ge2Cl3 both chemically and thermally.The crystal structure of Ph2Ge2Cl4 has been determined (R = 0.057), Ge-Ge 241.3(1) pm. - Keywords: Functional Digermanes, Synthesis, Structure
Phases of Diphenylgermanium Oxide(Ph2GeO)x, x = 3,4,n
Ross, Ludwig,Draeger, Martin
, p. 868 - 875 (2007/10/02)
Diphenylgermanium oxide can be obtained trimeric (6-membered ring, monoclinic crystals), tetrameric (8-membered ring, monoclinic and tetragonal crystals and monoclinic with half a mole of crystal ethanol) and polymeric with terminating hydroxy groups.Transitions are investigated by thermal analysis, mass spectra and 13C NMR spectra.The vibrational spectra (I.R. and Raman) of the forms are discussed.The crystal structure of the monoclinic (Ph2GeO)4 has been determined and refined to R = 0.051.The symmetry of the molecule is near to S4 (distances Ge-O 174.7-176.2, Ge-C 190.0-194.6 pm, angles Ge-O-Ge 131.2-136.9, O-Ge-O 107.8-110.3 deg). - Key words: Germanium, Polymorphism, Heterocycle, Conformation
Reactivite de cyclo- et tri-germazanes: Mise en evidence de la participation de germyleneamines dans des reactions d'insertion-elimination
Lacrampe, G.,Lavayssiere, H.,Riviere-Baudet, M.,Satge, J.
, p. 21 - 34 (2007/10/02)
Cyclogermazanes (R2GeNR')n (n=2,3), oligomers of germyleneamines, R2Ge=NR', are obtained through aminolysis or amonolysis of Ge-Cl bonds, by intramolecular transamination, or by reaction between chlorogermanes and dilithium amides.The oligomerization degree (n=2,3) is strongly dependent on the nature of the substituents bonded to nitrogen or germanium.Cleavage reactions by bifunctional protic reagents such as diols, dithiols, aminoalcohols, aminothiols and aminoacids have been studied and lead to the corresponding five-membered germa heterocycles resulting from the cleavage of two consecutive Ge-N bonds.Insertion reactions of either heterocumulenes and insaturated dipoles such as RNCO, RNCS, CO2, CS2, PhCHO or oxirane lead to ring expansion.Compounds resulting from diaddition of isocyanates and isothiocyanates to cyclogermazanes, decompose with formation transient germyleneamines which have been characterized by means of their 1,2-cycloaddition reactions with iso- or isothio-cyanates leading to unsatble diazagermetidiones, (or thiones).Similarly, adducts between cyclogermazanes and aldehydes , CO2, CS2 lead to cyclogermoxanes or cyclogermathianes through the corresponding germanones or germathiones. 1,3-Dipoles such as nitrones react with with cyclogermazanes at temperatures around 150 degree C to give unstable 1,3,5,2-oxadiazagermolidines.The reactivity of cyclogermazanes is enhanced in the presence of triethylamine or hexamethylphosphotriamide.The possibility of participation in the latter reactions for the monomeric germyleneamine R2Ge=NR' resulting from the equilibrium cyclogermazane germyleneamine is discussed.
On Heterocyclic Systems Containing Germanium, IV. 2,2,4,4,6,6-Hexaphenyl-1,3,5-trioxa-2,4,6-trigermacyclohexane, (Ph2GeO)3, a Monoplanar Intermediate in the Pseudo-Rotation Cycle for the Twist-Boat Conformation of a 6-Membered Ring
Ross, Ludwig,Draeger, Martin
, p. 615 - 621 (2007/10/02)
The title compound 1 has been synthesized by hydrolysis of Ph2GeCl2 in acetone.The crystal structure has been determined and refined to an R of 0.049.The conformation of the 6-membered ring Ge3O3 is monoplanar and is a possible intermediate for the racemi
