Reaction Of GeCl4 Research Articles

Ge(TenBu)4] - a single source precursor for the chemical vapour deposition of germanium telluride thin films.

Reaction of activated germanium with nBu2Te2 in THF solution was shown to be more effective for the preparation of the germanium(iv) tellurolate compound, [Ge(TenBu)4], than reaction of GeCl4 with LiTenBu in a 1 : 4 molar ratio in THF. The product was characterised by 1H, 13C{1H} NMR spectroscopy and microanalysis and evaluated as a single source precursor for the low pressure chemical vapour deposition of GeTe thin films. Depending upon deposition conditions, either dull grey films (predominantly elemental Te) or highly reflective (GeTe) films were obtained from the pure precursor. Grazing incidence X-ray diffraction shows that the highly reflective films are comprised of the rhombohedral α-GeTe phase, while scanning electron microscopy and energy dispersive X-ray analysis reveal rhomb-shaped crystallites with a 49(1) : 51(1)% Ge : Te ratio. This structure is also confirmed from Raman spectra. Van der Pauw measurements show ρ = 3.2(1) × 10-4 Ω cm and Hall electrical measurements indicate that the GeTe thin films are p-type, with a mobility of 8.4(7) cm2 V-1 s-1 and carrier concentration of 2.5(2) × 1021 cm-3. The high p-type concentration is most likely a result of the substantial Ge vacancies in its sub-lattice, in line with the EDX elemental ratios.

“Naked” S2O7 2– ions – the serendipitous formation of the disulfates [HPy]2[S2O7] and [bmim][HPy][S2O7] (HPy = pyridinium; bmim = 1-Butyl-3-methylimidazolium)

Abstract [bmim][HPy][S2O7] [monoclinic, P21/n, Z = 4, a = 825.78(2), b = 1545.30(3), c = 1410.80(3) pm, β = 104.726(1)°, V = 1741.16(7) Å3] was obtained as a side product in the reaction of GeCl4, oleum (65% SO3), and the pyridine (Py) complex Py·SO3 in the ionic liquid 1-butyl-3-methylimidazolium hydrogensulfate, [bmim][HSO4], at 50 °C. Charge compensation of the disulfate ion is achieved by the counterions pyridinium, [HPy]+, and 1-butyl-3-methylimidazolium, [bmim]+. The crystal structure shows alternating layers of [bmim]+ cations on one hand and [HPy]+ cations and disulfate anions on the other hand. Pyridinium disulfate, [HPy]2[S2O7] [orthorhombic, P212121, Z = 4, a = 801.35(1), b = 1257.62(2), c = 1357.22(3) pm, V = 1367.80(4) Å3] was formed unexpectedly in the reaction of Eu2O3 and Py·SO3 in pyridine. The crystal structure exhibits a layer-like arrangement of disulfate and pyridinium moieties in the ab plane. In both compounds, the disulfate groups are essentially uncoordinated allowing for a detailed inspection of “naked” S2O7 2– ions.

The Surprising Reactions of 1,3-Di-tert-butyl-2,2-dichloro-1,3-diaza-2-germa-4-cyclopentene

1,3-Di-tert-butyl-2,2-dichloro-1,3-diaza-2-germa-4-cyclopentene (1) was synthesized from N,N-di-tert-butyl-1,2-diiminoethane (NN) and GeCl2. 1 undergoes slow transformation at room temperature to the bicyclic compound 6. Compound 6 is also produced in the reaction of GeCl4 with N,N‘-dilithio-1,4-diaza-2-butene. Treatment of 1 with GeCl2 yields a complex salt, (NN)Ge-Cl+GeCl3- (7).

Organomagnesium Synthesis of sec-Butyl- and tert-Alkylchlorogermanes and Their Reaction with Ethynylmagnesium Bromide

The limits of application of organomagnesium synthesis to the substitution of chlorine atoms in tetrachlorogermane with bulky alkyl groups are established. The reaction of tetrachlorogermane with 2-butylmagnesium chloride leads to the substitution of one, two, or three chlorine atoms, yielding the corresponding alkylchlorogermanes (MeEtCH)nGeCl4-n . The reaction of GeCl4 with tert-alkylmagnesium halides leads to the substitution of only one chlorine atom, yielding tert-alkyltrichlorogermanes RMe2CGeCl3 (R = Me, Et, Bu). tert-Butyltrichlorogermane reacts with ethylmagnesium bromide to give ethyl(tert-butyl)dichlorogermane. Isopropyltrichlorogermane reacts with tert-butylmagnesium chloride to give isopropyl(tert-butyl)dichlorogermane. This shows that the organomagnesium synthesis does allow linking of two bulky substituents to the germanium atom. The reaction of tert-alkyltrichlorogermanes and 2-butyltrichlorogermane in THF with ethynylmagnesium bromide, in which the hydrocarbon group is the most sterically accessible, allows substitution of all the three chlorine atoms, yielding the corresponding alkyl(triethynyl)germanes. The latter compounds react with the Grignard reagent and trimethylchlorosilane to give the corresponding alkyl(trimethylsilylethynyl)germanes.

Field‐effect transistor based on organosoluble germanium nanoclusters

AbstractThe structural and electrical properties of organosoluble germanium nanoclusters are studied. The organogermanium nanocluster (OGE) is a polygermane with a three‐dimensional σ‐conjugated chain. The OGE is prepared from GeCl4 by a simple one‐pot reaction, where the germanium nanocluster is obtained by the reaction of GeCl4 using magnesium metal and the capping reaction of the chlorine group by an alkyl Grignard reagent in tetrahydrofuran. The optical energy gap of the tert‐butyl‐substituted OGE is lower than that of the n‐propyl‐substituted OGE, corresponding to the higher molecular weight and the larger extent of the σ‐conjugation along the GeGe chain. The conductivity of the OGE is enhanced by heat treatment, which induces the elimination of organic substituents, the reconstruction of the GeGe chain, and the extension of a three‐dimensional germanium network among germanium clusters. The field‐effect transistor fabricated by a coating technique using the tert‐butyl‐substituted OGE shows signal amplification properties. Copyright © 2005 John Wiley & Sons, Ltd.

The reaction of GeCl4 with primary and secondary phosphines.

Reaction of GeCl4 and CyPH2 leads to a range of products from which crystals of [CyPH3]+[GeCl3]- have been obtained. The major intermediate in this reaction, Cy(H)PGeCl3, can be obtained as the dominant product only when an excess of GeCl4 is used in the preparation. Similarly, crystals of [Ph2PH2]+[GeCl3]- have been obtained from reaction of Ph2PH and GeCl4(1 : 1). The structures of both primary and secondary phosphonium cations are reported. Aerosol-assisted and low-pressure chemical vapour deposition experiments using Cy(H)PGeCl3 as precursor lead to the deposition of thin films containing both germanium and phosphorus, contaminated with large amounts of oxygen. GeP has been identified as components of the film from bandgap measurements.

Gas Phase Reaction of Tetrachlorogermane with Conjugated Dienes in the Presence of Hexachlorodisilane Initiator

Studies of the reaction of GeCl4 with acyclic conjugated dienes (1,3-butadiene, 2-methyl-1,3- butadiene, 2,3-dimethyl-1,3-butadiene) and cyclopentadiene in the presence of Si2Cl6 initiator were carried out. With acyclic dienes, corresponding 1,1-dichloro-1-germacyclo-3-pentenes and 1,1-dichloro-1-silacyclo-3- pentenes are preferrably formed. With cyclopentadiene the main reaction products are cyclopentenyltrichlorogermanes and cyclopentenyltrichlorosilanes formed respectively by hydrogermylation and hydrosilylation of the starting diene. The explanation of the established rule is offered.

Reaction of GeCl4 with some phosphorus and arsenic donor ligands; crystal structures of the germanium(II) complex [Bun3PCl][GeCl3] and the germanium(IV) complex GeCl4(AsMe3)2, the first reported example of a tertiary arsine complex of GeIV

The tertiary phosphines PR3 {R3 = Me3, Et3, Prn3, Bun3, But3, (C6H11)3, [2,6-(CH3O)2C6H3]3, [2,4,6-(CH3O)3C6H2]3, (C6H5CH2)3, (Me2N)3, (Et2N)3, (Prn2N)3, Ph2Et or Ph3} and tertiary arsines AsR3 (R = Ph or Me) have been treated with germanium tetrachloride in both a 1∶1 and 2∶1 stoichiometric ratio in diethyl ether solution. In the tertiary phosphine reactions a redox reaction occurs to produce the ionic germanium(II) complexes [R3PCl][GeCl3] in near to quantitative yield, the chlorophosphinium cation being identified by 31P-{H} NMR spectroscopy. No evidence for the previously reported molecular germanium(IV) adducts GeCl4(PR3)2 was observed, apart from the possible assignments of minor peaks in the 31P-{H} NMR spectrum for some of the products. The crystal structure of [Bun3PCl][GeCl3] revealed no interaction between the cation and anion, in direct contrast to the only other reported complex of this stoichiometry, [Pri3PBr][GeBr3]. No reaction was observed between PPh3 and GeCl4. The reaction of AsMe3 with GeCl4 in both a 1∶1 and 2∶1 stoichiometric ratio produced the molecular trans-octahedral germanium(IV) complex, GeCl4(AsMe3)2, the first crystallographically characterised germanium(IV) tertiary arsine complex [d(Ge–As) = 2.472(1) Å]. No reaction occurred between GeCl4 and AsPh3.

Synthese de Nouvelles Porphyrines Germaniees S-Substituees PorGe(SCH2CH2NH.X)2X=H.HCL, (CH2)3NH2.2HCI

Abstract Dichlorogermylporphyrins have been obtained from the reaction of GeCl4 or GeCl2. dioxane with porphyrin TMPyPH2, TAPPH2 and TPPSH2 in quinoline or pyridine. These dichlorogermyl porphyrins reacted in pyridine with HSCH2CH2NH.X (X=H.HCl, -(CH2)3NH2.2HCl) to lead to germylporphyrins with new ligands on germanium : cysteamine and N-(2-thioethyl)-1,3-diami nopropane hydrochloride.

ChemInform Abstract: Synthesis and Molecular Structure of EtGe(SePh)3: An Unusual Example of Alkylation by LiEt3BH.

AbstractThe reaction of GeCl4 (III) with 4 equiv. LiSePh (IV) generated in situ by the reductive cleavage of (I) with (II) yields, in addition to the expected product (V), the compound (VI) resulting from germanium ethylation.

Synthesis and molecular structure of EtGe(SePh)3: an unusual example of alkylation by LiEt3BH

The reaction of GeCl4 (III) with 4 equiv. LiSePh (IV) generated in situ by the reductive cleavage of (I) with (II) yields, in addition to the expected product (V), the compound (VI) resulting from germanium ethylation.