7782-65-2Relevant academic research and scientific papers
Ultrapurification of 76Ge-enriched GeH4 by distillation
Adamchik,Bulanov,Sennikov,Churbanov,Sozin,Chernova,Kosheleva,Troshin
, p. 694 - 696 (2011)
76Ge-enriched germane has been ultrapurified by low-temperature distillation. The nature and concentration of molecular impurities in the germane samples were determined by gas chromatography/mass spectrometry, high-resolution Fourier transform IR spectroscopy, and gas chromatography. The distillate contains no more than 10-5 mol % hydrocarbons, 10 -4 mol % carbon dioxide, 10-3 to 10-1 mol % digermane and trigermane, and -5 mol % other impurities. A distinctive feature of the impurity composition of the isotopically enriched germane samples is the presence of silicon tetrafluoride and sulfur hexafluoride impurities. Pleiades Publishing, Ltd., 2011.
Effect of temperature on B(C6F5)3-catalysed reduction of germanium alkoxides by hydrosilanes - a new route to germanium nanoparticles
Cypryk, Marek,Fortuniak, Witold,Mizerska, Urszula,Rubinsztajn, Slawomir,Uznanski, Pawel,Zakrzewska, Joanna
, p. 7319 - 7323 (2020)
Reduction of Ge(OBu)4with PhMe2SiH catalyzed by B(C6F5)3at ambient temperature leads to GeH4. We discovered that a higher temperature (above 100 °C) completely changes the reaction course by producing germanium nanoparticles (Ge NPs) in high yield. This process provides a simple one-pot method for Ge NPs synthesis from readily available substrates under mild conditions.
Laser CVD of nanodisperse Ge-Sn alloys obtained by dielectric breakdown of SnH4/GeH4 mixtures
Krenek, Tomas,Bezdicka, Petr,Murafa, Nataliya,Subrt, Jan,Pola, Josef
, p. 1464 - 1467 (2009)
TEA CO2 laser-induced dielectric breakdown of an equi-molar mixture of gaseous stannane and germane in Ar allows decomposition of both metal hydrides and chemical vapour deposition of the nanostructured Ge/Sn films. Analysis of the films by FTI
Dual Role of Doubly Reduced Arylboranes as Dihydrogen- and Hydride-Transfer Catalysts
Von Grotthuss, Esther,Prey, Sven E.,Bolte, Michael,Lerner, Hans-Wolfram,Wagner, Matthias
supporting information, (2019/04/17)
Doubly reduced 9,10-dihydro-9,10-diboraanthracenes (DBAs) are introduced as catalysts for hydrogenation as well as hydride-transfer reactions. The required alkali metal salts M2[DBA] are readily accessible from the respective neutral DBAs and Li metal, Na metal, or KC8. In the first step, the ambiphilic M2[DBA] activate H2 in a concerted, metal-like fashion. The rates of H2 activation strongly depend on the B-bonded substituents and the counter cations. Smaller substituents (e.g., H, Me) are superior to bulkier groups (e.g., Et, pTol), and a Mes substituent is even prohibitively large. Li+ ions, which form persistent contact ion pairs with [DBA]2-, slow the H2-addition rate to a higher extent than more weakly coordinating Na+/K+ ions. For the hydrogenation of unsaturated compounds, we identified Li2[4] (Me substituents at boron) as the best performing catalyst; its substrate scope encompasses Ph(H)CNtBu, Ph2CCH2, and anthracene. The conversion of E-Cl to E-H bonds (E = C, Si, Ge, P) was best achieved by using Na2[4]. The latter protocol provides facile access also to Me2Si(H)Cl, a most important silicone building block. Whereas the H2-transfer reaction regenerates the dianion [4]2- and is thus immediately catalytic, the H--transfer process releases the neutral 4, which has to be recharged by Na metal before it can enter the cycle again. To avoid Wurtz-type coupling of the substrate, the reduction of 4 must be performed in the absence of the element halide, which demands an alternating process management (similar to the industrial anthraquinone process).
Dual Role of Doubly Reduced Arylboranes as Dihydrogen- and Hydride-Transfer Catalysts
Von Grotthuss, Esther,Prey, Sven E.,Bolte, Michael,Lerner, Hans-Wolfram,Wagner, Matthias
supporting information, p. 6082 - 6091 (2019/04/17)
Doubly reduced 9,10-dihydro-9,10-diboraanthracenes (DBAs) are introduced as catalysts for hydrogenation as well as hydride-transfer reactions. The required alkali metal salts M2[DBA] are readily accessible from the respective neutral DBAs and Li metal, Na metal, or KC8. In the first step, the ambiphilic M2[DBA] activate H2 in a concerted, metal-like fashion. The rates of H2 activation strongly depend on the B-bonded substituents and the counter cations. Smaller substituents (e.g., H, Me) are superior to bulkier groups (e.g., Et, pTol), and a Mes substituent is even prohibitively large. Li+ ions, which form persistent contact ion pairs with [DBA]2-, slow the H2-addition rate to a higher extent than more weakly coordinating Na+/K+ ions. For the hydrogenation of unsaturated compounds, we identified Li2[4] (Me substituents at boron) as the best performing catalyst; its substrate scope encompasses Ph(H)C=NtBu, Ph2C=CH2, and anthracene. The conversion of E-Cl to E-H bonds (E = C, Si, Ge, P) was best achieved by using Na2[4]. The latter protocol provides facile access also to Me2Si(H)Cl, a most important silicone building block. Whereas the H2-transfer reaction regenerates the dianion [4]2- and is thus immediately catalytic, the H--transfer process releases the neutral 4, which has to be recharged by Na metal before it can enter the cycle again. To avoid Wurtz-type coupling of the substrate, the reduction of 4 must be performed in the absence of the element halide, which demands an alternating process management (similar to the industrial anthraquinone process).
H2MBH2 and M(μ-H)2BH2 Molecules Isolated in Solid Argon: Interelement M-B and M-H-B Bonds (M = Ge, Sn)
Zhao, Jie,Beckers, Helmut,Huang, Tengfei,Wang, Xuefeng,Riedel, Sebastian
, p. 2218 - 2227 (2018/02/23)
Laser-ablated boron atoms react with GeH4 molecules to form novel germylidene borane H2GeBH2, which undergoes a photochemical rearrangement to the germanium tetrahydroborate Ge(μ-H)2BH2 upon irradiation with light of λ = 405 nm. For comparison, the boron atom reactions with SnH4 only gave the tin tetrahydroborate Sn(μ-H)2BH2. Infrared matrix-isolation spectroscopy with deuterium substitution and the state-of-the-art quantum-chemical calculations are used to identify these species in solid argon. A planar structure of H2GeBH2 with an electron-deficient B-Ge bond with a partial multiple bond character (bond order = 1.5) is predicted by quantum-chemical calculations. In the case of M(μ-H)2BH2 (M = Ge, Sn) two 3c-2e B-H-M hydrogen bridged bonds are formed by donation of electrons from the B-H σ-bonds into empty p-orbitals of M.
Molecular synthesis of high-performance near-ir photodetectors with independently tunable structural and optical properties based on Si-Ge-Sn
Xu, Chi,Beeler, Richard T.,Grzybowski, Gordon J.,Chizmeshya, Andrew V.G.,Smith, David J.,Menendez, Jose,Kouvetakis, John
, p. 20756 - 20767 (2013/02/23)
This Article describes the development of an optimized chemistry-based synthesis method, supported by a purpose-built reactor technology, to produce the next generation of Ge1-x-ySixSny materials on conventional Si(100) and Ge(100) platforms at gas-source molecular epitaxy conditions. Technologically relevant alloy compositions (1-5% Sn, 4-20% Si) are grown at ultralow temperatures (330-290 C) using highly reactive tetragermane (Ge4H10), tetrasilane (Si4H10), and stannane (SnD4) hydride precursors, allowing the simultaneous increase of Si and Sn content (at a fixed Si/Sn ratio near 4) for the purpose of tuning the bandgap while maintaining lattice-matching to Ge. First principles thermochemistry studies were used to explain stability and reactivity differences between the Si/Ge hydride sources in terms of a complex interplay among the isomeric species, and provide guidance for optimizing process conditions. Collectively, this approach leads to unprecedented control over the substitutional incorporation of Sn into Si-Ge and yields materials with superior quality suitable for transitioning to the device arena. We demonstrate that both intrinsic and doped Ge1-x-ySixSny layers can now be routinely produced with defect-free microstructure and viable thickness, allowing the fabrication of high-performance photodetectors on Ge(100). Highlights of these new devices include precisely adjustable absorption edges between 0.87 and 1.03 eV, low ideality factors close to unity, and state-of-the-art dark current densities for Ge-based materials. Our unequivocal realization of the molecules to device concept implies that GeSiSn alloys represent technologically viable semiconductors that now merit inclusion in the class of ubiquitous Si, Ge, and SiGe group IV systems.
Electrochemical preparation of germane
Turygin,Smirnov,Shalashova,Khudenko,Nikolashin,Fedorov,Tomilov
, p. 1081 - 1085 (2009/02/06)
Germane has been prepared through the electrochemical reduction of the germanate anion in alkaline solutions with a current efficiency of 40-45%. Active solution circulation in the cathodic zone and the use of an Sn or Cd cathode are shown to raise the germane yield. The current density and initial solution concentration have a weak effect on the reduction process.
Single vibronic level emission spectroscopic studies of the ground state energy levels and molecular structures of jet-cooled HGeBr, DGeBr, HGeI, and DGeI
Tackett, Brandon S.,Li, Yunjing,Clouthier, Dennis J.,Pacheco, Kezia L.,Schick, G. Alan,Judge, Richard H.
, (2008/10/09)
Single vibronic level dispersed fluorescence spectra of jet-cooled HGeBr, DGeBr, HGeI, and DGeI have been obtained by laser excitation of selected bands of the A1 A″-X 1 A′ electronic transition. The measured ground state vibrational intervals were assigned and fitted to anharmonicity expressions, which allowed the harmonic frequencies to be determined for both isotopomers. In some cases, lack of a suitable range of emission data necessitated that some of the anharmonicity constants and vibrational frequencies be estimated from those of HGeCl/DGeCl and the corresponding silylenes (HSiX). Harmonic force fields were obtained for both molecules, although only four of the six force constants could be determined. The ground state effective rotational constants and force field data were combined to calculate average (rz) and approximate equilibrium (rze) structures. For HGeBr rez(GeH) = 1.593(9) A, rez(GeBr)=2.325(21) A, and the bond angle was fixed at our CCSD(T)/aug-cc-pVTZ ab initio value of 93.6°. For HGeI we obtained rez(GeH) = 1.589(1) A, r ez(GeI)=2.525(5) A, and bond angle=93.2°. Franck-Condon simulations of the emission spectra using ab initio Cartesian displacement coordinates reproduce the observed intensity distributions satisfactorily. The trends in structural parameters in the halogermylenes and halosilylenes can be readily understood based on the electronegativity of the halogen substituent.
Infrared spectra of group 14 hydrides in solid hydrogen: Experimental observation of Pbh4, Pb2H2, and Pb2H4
Wang, Xuefeng,Andrews, Lester
, p. 6581 - 6587 (2007/10/03)
Laser-ablated Si, Ge, Sn, and Pb atoms have been co-deposited with pure hydrogen at 3.5 K to form the group 14 hydrides. The initial SiH2 product reacts completely to SiH4, whereas substantial proportions of GeH2, SnH
