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Dietrich Gudat Asadollah Haghverdi Timo Gans-Eichler Martin Nieger 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1637-1640
The high intrinsic stability of 1,3,2-diazaphospholenium cations enhances ionic polarization of covalent P--X bonds in P -halogeno- and P -hydrido-diazaphospholenes. The physical properties of the latter suggest a hydridic nature of the P--H bond, and their reactivities display an "Umpolung" as compared to known reaction patterns of phosphines. 相似文献
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Potential hydrogen storage ternaries Zr3FeH7 and Zr2FeH5, are studied from ab initio with the purpose of identifying changes in electronic structures and bonding properties. Cohesive energy trends: Ecoh. (ZrH2) > Ecoh. (Zr2FeH5) > Ecoh. (Zr3FeH7) > Ecoh. (hypothetic-FeH) indicate a progressive destabilization of the binary hydride ZrH2 through adjoined Fe so that Zr3FeH7 is found less cohesive than Zr2FeH5. From the energy volume equations of states EOS the volume increase upon hydriding the intermetallics leads to higher bulk moduli B0 explained by the Zr/Fe–H bonding. Fe–H bond in Zr2FeH5 leads to annihilate magnetic polarization on Fe whereas Fe magnetic moment develops in Zr3FeH7 identified as ferromagnetic in the ground state. These differences in magnetic behaviors are due to the weakly ferromagnetic Fe largely affected by lattice environment, as opposed to strongly ferromagnetic Co. Hydrogenation of the binary intermetallics weakens the inter-metal bonding and favors the metal–hydrogen bonds leading to more cohesive hydrides as with respect to the pristine binaries. Charge analyses point to covalent like Fe versus ionic Zr and hydrogen charges ranging from covalent H−0.27 to more ionic H−0.5. 相似文献
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The adsorption and decomposition of monoethylgermane (GeH3Et) on the Si(100)-(2×1) surface was investigated with the intent of elucidating the surface processes leading to the deposition of germanium. The low-temperature adsorption of the molecule was explored, as well as its thermal decomposition. H2 and C2H4 are observed as the desorption products in temperature-programmed desorption experiments. The ethylene is produced by a hydride elimination reaction within the adsorbed ethyl groups. The amount of Ge which can be deposited in a reaction cycle is correlated with the number of sites occupied by the ethyl groups upon the dissociation of GeH3Et. 相似文献
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Martin Sahlberg Premysl Beran Thomas Kollin Nielsen Yngve Cerenius Krisztina Kads Marko P.J. Punkkinen Levente Vitos Olle Eriksson Torben R. Jensen Yvonne Andersson 《Journal of solid state chemistry》2009,182(11):3113-3117
A novel aluminium rich alloy for hydrogen storage has been discovered, ScAl0.8Mg0.2, which has very promising properties regarding hydrogen storage capacity, kinetics and stability towards air oxidation in comparison to hydrogen absorption in state-of-the-art intermetallic compounds. The absorption of hydrogen was found to be very fast, even without adding any catalyst, and reversible. The discovered alloy crystallizes in a CsCl-type structure, but decomposes to ScH2 and Al(Mg) during hydrogen absorption. Detailed analysis of the hydrogen absorption in ScAl0.8Mg0.2 has been performed using in situ synchrotron radiation powder X-ray diffraction, neutron powder diffraction and quantum mechanical calculations. The results from theory and experiments are in good agreement with each other. 相似文献
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In this work, we study the modification of hydrogenated diamond films deposited on silicon resulting from its exposure to DBr followed by an annealing above 600 K, using high resolution electron energy loss spectroscopy (HREELS). This procedure results in silicon carbide SiC formation within the diamond film, as evidenced by the observation of a loss peak at 117 meV and its first harmonic at 233 meV in HREEL spectra. This diamond surface modification is interpreted as resulting from the reaction of products of the silicon support thermally activated etching with hydrogenated diamond. 相似文献
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Dr. Maximilian Muhr Hao Liang Dr. Lars Allmendinger Raphael Bühler Fabrizio E. Napoli Dr. Dardan Ukaj Dr. Mirza Cokoja Dr. Christian Jandl Dr. Samia Kahlal Prof. Dr. Jean-Yves Saillard Dr. Christian Gemel Prof. Dr. Roland A. Fischer 《Angewandte Chemie (International ed. in English)》2023,62(36):e202308790
The bimetallic, decanuclear Ni3Ga7-cluster of the formula [Ni3(GaTMP)3(μ2-GaTMP)3(μ3-GaTMP)] ( 1 , TMP=2,2,6,6-tetramethylpiperidinyl) reacts reversibly with dihydrogen under the formation of a series of (poly-)hydride clusters 2 . Low-temperature 2D NMR experiments at −80 °C show that 2 consist of a mixture of a di- ( 2Di ), tetra- ( 2Tetra ) and hexahydride species ( 2Hexa ). The structures of 2Di and 2Tetra are assessed by a combination of 2D NMR spectroscopy and DFT calculations. The cooperation of both metals is essential for the high hydrogen uptake of the cluster. Polyhydrides 2 are catalytically active in the semihydrogenation of 4-octyne to 4-octene with good selectivity. The example is the first of its kind and conceptually relates properties of molecular, atom-precise transition metal/main group metal clusters to the respective solid-state phase in catalysis. 相似文献
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Rafael Schiwon Beatrice Braun Ramona Metzinger Christian Limberg 《无机化学与普通化学杂志》2016,642(21):1198-1206
While addition of [Cp2ReH] to [Bi(OtBu)3] leads to an equilibrium containing [Cp2Re‐Bi(OtBu)2], [{Cp2Re}2Bi(OtBu)], tBuOH and [CpRe(μ‐η5,η1‐C5H4)Bi–ReCp2], in the presence of water [{(Cp2Re)2Bi}2O] ( 1 ) is formed selectively. Also [FpH] [Fp = (η5‐C5H5)(CO)2Fe] can be employed as a precursor to form heterometallic bismuth compounds. Synthesis of [FpBi{OCH(CF3)2}2]2 ( 5 ) can be achieved by reaction of [FpH] with [Bi{OCH(CF3)2}3(thf)]2 and carboxylates [FpBi(O2CR)2]2 are generated upon treatment of [FpH] with [Bi(O2CR)3] (R = CH3, tBu). While the compounds [Fp‐Bi(O2CR)2]2 can also be obtained from reactions with Fp‐Fp, they are formed far more readily using [FpH] as the precursor. They typically crystallize as dimers, like the alkoxide 5 . A monomeric compound of the type [Fp‐BiX2] ( 6 ) could be isolated for X = thd (tetramethylheptanedionate), that is, after the reaction of [FpH] with [Bi(thd)3]. Altogether, the results demonstrate the potential of [FpH] as a precursor for [Fp‐BiX2] compounds, which are formed in reactions with bismuth alkoxides, carboxylates and diketonates. 相似文献
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In this study, we developed a microscope for the simultaneous acquisition of optical sum frequency (SF) and second harmonic (SH) intensity images in UHV conditions, and observed resonant electronic and vibrational images of the H-Si(1 1 1) surface after IR light irradiation of pulse width ∼6 μs. The SH intensity images showed a spatial distribution of resonant electronic states, associated with the dangling bonds formed after hydrogen desorption induced by the IR light pulses. This result indicates that the hydrogen coverage decreased to less than ∼0.6 ML in the irradiated area. The SF intensity images before the IR light pulse irradiation showed signals attributed to Si-H stretching vibration on the H-Si(1 1 1) surface. After the IR light pulse irradiation, non-resonant SF signals appeared in the irradiated area. The non-resonant SF signals may originate from a nonlinear optical transition involving the surface electronic levels in the dangling bonds. We also found an unidentified bonding state on the edges of the irradiated area in some light conditions. Both the resonant and non-resonant signals were very weak in this area. 相似文献
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Werner Uhl Lars Cuypers Gertraud Geiseler Klaus Harms Werner Massa 《无机化学与普通化学杂志》2002,628(5):1001-1006
Syntheses and Crystal Structures of Dialkylgallium Hydrides — Dimeric versus Trimeric Formula Units Dialkylgallium hydrides (R = Me, Et, iPr, iBu, neopentyl) were obtained on two different synthetic routes. The dimethyl and diethyl compounds were formed by the reaction of LiH with the corresponding dialkylgallium chlorides via lithium dialkyldihydridogallate intermediates, which so far have not been isolated in a pure form. On the second route, trialkylgallium compounds were treated with [GaH3·NMe2Et] to yield the dialkylgallium hydrides by a substituent exchange reaction. The dimethyl, diethyl and diisopropyl compounds are trimeric in solution. That trimeric structure was verified for the diisopropyl derivative by a crystal structure determination. Di(neopentyl)gallium hydride has a dimeric structure in solution and in the solid state. 相似文献