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Electronic structure methods based on density functional theory and coupled-cluster theory were employed to characterize elementary steps for the gas-phase thermal decomposition of bis(1,2,4-oxadiazole)bis(methylene) dinitrate (BODN). As typically found for nitrate ester-functionalized compounds, NO2 and HONO eliminations were the most energetically favorable unimolecular paths for the parent molecule's decomposition. From there, sequences of unimolecular reactions for daughters of the initiation steps were postulated and characterized. For intermediates found to have barriers to unimolecular decomposition that would make their rate at the temperatures and time scales of interest negligible, their decomposition via H-atom abstraction and radical-addition reactions was characterized. Creating a comprehensive network that can be employed to develop a detailed finite-rate chemical kinetics mechanism for simulating BODN's decomposition, the results provide a basis for modeling BODN's combustion, as well as its response to thermal loads germane to its aging, storage, and handling.

Heteroepitaxial growth of Ge films on Si is necessary for the progress of integrated Si photonics technology. In this work, an in-house assembled plasma enhanced chemical vapor deposition reactor was used to grow high quality epitaxial Ge films on Si (100) substrates. Low economic and thermal budget were accomplished by the avoidance of ultra-high vacuum conditions or high temperature substrate pre-deposition bake for the process. Films were deposited with and without plasma assistance using germane (GeH4) precursor in a single step at process temperatures of 350–385 °C and chamber pressures of 1–10 Torr at various precursor flow rates. Film growth was realized at high ambient chamber pressures (&gt, 10−6 Torr) by utilizing a rigorous ex situ substrate cleaning process, closely controlling substrate loading times, chamber pumping and the dead-time prior to the initiation of film growth. Plasma allowed for higher film deposition rates at lower processing temperatures. An epitaxial growth was confirmed by X-Ray diffraction studies, while crystalline quality of the films was verified by X-ray rocking curve, Raman spectroscopy, transmission electron microscopy and infra-red spectroscopy.

The chemical dynamics of the elementary reaction of ground state atomic silicon (Si; 3 P) with germane (GeH4 ; X1 A1 ) were unraveled in the gas phase under single collision condition at a collision energy of 11.8±0.3 kJ mol-1 exploiting the crossed molecular beams technique contemplated with electronic structure calculations. The reaction follows indirect scattering dynamics and is initiated through an initial barrierless insertion of the silicon atom into one of the four chemically equivalent germanium-hydrogen bonds forming a triplet collision complex (HSiGeH3 ; 3 i1). This intermediate underwent facile intersystem crossing (ISC) to the singlet surface (HSiGeH3 ; 1 i1). The latter isomerized via at least three hydrogen atom migrations involving exotic, hydrogen bridged reaction intermediates eventually leading to the H3 SiGeH isomer i5. This intermediate could undergo unimolecular decomposition yielding the dibridged butterfly-structured isomer 1 p1 (Si(μ-H2 )Ge) plus molecular hydrogen through a tight exit transition state. Alternatively, up to two subsequent hydrogen shifts to i6 and i7, followed by fragmentation of each of these intermediates, could also form 1 p1 (Si(μ-H2 )Ge) along with molecular hydrogen. The overall non-adiabatic reaction dynamics provide evidence on the existence of exotic dinuclear hydrides of main group XIV elements, whose carbon analog structures do not exist.

The previously unknown silylgermylidyne radical (H3 SiGe; X2 A'') was prepared via the bimolecular gas phase reaction of ground state silylidyne radicals (SiH; X2 Π) with germane (GeH4 ; X1 A1 ) under single collision conditions in crossed molecular beams experiments. This reaction begins with the formation of a van der Waals complex followed by insertion of silylidyne into a germanium-hydrogen bond forming the germylsilyl radical (H3 GeSiH2 ). A hydrogen migration isomerizes this intermediate to the silylgermyl radical (H2 GeSiH3 ), which undergoes a hydrogen shift to an exotic, hydrogen-bridged germylidynesilane intermediate (H3 Si(μ-H)GeH); this species emits molecular hydrogen forming the silylgermylidyne radical (H3 SiGe). Our study offers a remarkable glance at the complex reaction dynamics and inherent isomerization processes of the silicon-germanium system, which are quite distinct from those of the isovalent hydrocarbon system (ethyl radical; C2 H5 ) eventually affording detailed insights into an exotic chemistry and intriguing chemical bonding of silicon-germanium species at the microscopic level exploiting crossed molecular beams.

Matrix isolation infrared spectroscopy combined with quantum-chemical calculations were employed to study the reactions of calcium atoms with silane, germane, and stannane in a 4 K argon matrix. The ion pairs [HCa]+ and [EH3]- (E = Si, Ge, and Sn) in both the classical structure HCaEH3 and the bridged structure HCa(μ-H)3E were identified based on the H/D isotopic substitution experiments and quantum-chemical calculations. The results show that the reaction between ground-state Ca and EH4 proceeds inefficiently, and only after the photolytic activation of Ca atoms to the Ca(1P:4s4p) state does insertion occur to give HCaEH3, which rearranges to HCa(μ-H)3E upon photolysis. Topological analysis of the electronic structure suggests that the nonclassical structure HCa(μ-H)3E is formed by the electrostatic interaction with charge-inverted hydrogen bridge bond, while HCaEH3 is dominated by (HCa)+(EH3)- ion pair interactions.

The synthesis of a variety of bis(catecholato)germanes is reported. The Lewis acidity of the bis(catecholato)germanes was assessed using the experimental Gutmann–Beckett method and computational FIA and GEI methods. The oligomerization of alkenes using bis(catecholato)germanes demonstrates the use of these complexes in catalysis. The use of donor additives in the dimerization of α-methylstyrene resulted in selectivity control comparable to transition metal catalyst systems.

We report on the growth of Sn-catalyzed GeSn nanowires (NWs) having a GeSn core and a c-Ge shell in the presence of germane plasma at substrate temperatures (TS) below the GeSn eutectic temperature (TE), containing an exceptional Sn concentration of 30 at. % in their core. The differences between the NWs produced at TS above and below TE of the GeSn alloy are highlighted. Two types of NW growth process are identified: the previously reported in-plane solid–liquid–solid (IPSLS) process for TS ≥ TE and a plasma-assisted IPSLS (PA-IPSLS) method taking place at TS < TE; the crucial role of plasma in providing the energy necessary to melt the Sn catalyst at substrate temperatures lower than TE is discussed. The thermal activation window for each method is determined. The PA-IPSLS process is shown to provide an efficient strategy for the growth of crystalline GeSn NWs with a high Sn incorporation in a growth duration of less than 3 min.

The intra- and inter molecular inter-ring η 6 ⇌ η 6 -haptotropic rearrangements (IRHR), occurring by involving interactions to Ge atoms in arylgermanes, were investigated theoretically and experimentally. The new methods for the synthesis of non-symmetrical polyaromatic Ge compounds were elaborated. Digermane Ph 3 GeGeMe 2 Cl ( 2 ) was obtained from Ph 3 GeGeMe 2 NMe 2 ( 1 ) under action of Me 3 SiCl. Aryl digermane Ph 3 GeGeMe 2 (η 6 -C 6 H 5 )Cr(CO) 3 ( 4 ) was obtained after lithiation of (η 6 -C 6 H 6 )Cr(CO) 3 ( 3 ) with subsequent interaction with 2 . It was established that thermally induced intra molecular IRHR in 4 is not observed experimentally; at similar reaction conditions in the presence of tetralin C 10 H 12 ( 7 ) the bimolecular inter molecular IRHR occurs giving (η 6 -C 10 H 12 )Cr(CO) 3 ( 8 ). DFT analysis of the intra molecular IRHRs for model germane ( p -Tol) 2 Ge(H)(η 6 -Tol- p )Cr(CO) 3 ( MC1 ) and digermane Ph 3 GeGeH 2 (η 6 -Ph)Cr(CO) 3 ( MC2 ) indicates a plausible effect of 3c-2e (agostic) Ge–H···Cr interaction on success of such rearrangement. The theoretical activation barrier is determined to be in the range of 35–37 kcal/mol. The model compound (η 6 -C 6 H 3 (GeHPh 2 )Me 2 - p )Cr(CO) 3 ( 12 ) was obtained from (η 6 -C 6 H 4 Me 2 - p )Cr(CO) 3 ( 11 ). The decomposition of 12 was observed under conditions of thermally induced IRHR. Molecular structures of 8 , 11 and 12 in a crystal were investigated by XRD.

The spectra of germane 72GeH4 enriched up to 99.9% in the sample were recorded with high resolution (0.003 cm − 1 ) at different pressures with the Bruker IFS 125HR Fourier transform spectrometer (Nizhny Novgorod, Russia). The region of 700–4400 cm − 1 , where the Dyad and Pentad are located, was theoretically analyzed. The 9112 transitions belonging to the seven “cold” bands (6761 transitions) of the Dyad and Pentad and to the nine “hot” Dyad–Pentad bands (2351 transitions) were assigned and analyzed with an effective hamiltonian model which takes into account the presence of resonance interactions. The obtained set of 53 fitted parameters reproduces the initial 9112 experimental line positions with a d r m s = 2.44 × 10 − 4 cm − 1 .

Polygermanes are germanium-based analogues of polyolefins and possess polymer backbones made up catenated Ge atoms. In the present contribution we report the preparation of a stable germanium polyethylene analogue – polydihydrogermane (i.e., (GeH2)n) – via two straightforward approaches that involve topotactic deintercalation of the CaGe Zintl phase. The resulting (GeH2)n possess morphologically dependent chemical and electronic properties and thermally decompose to yield amorphous hydrogenated Ge. We also show that the resulting (GeH2)n provide a platform from which functionalized polygermanes can be prepared via thermally-induced hydrogermylation-mediated pendant group substitution. This facile one-step derivatization reaction exploits Ge–H reactivity and opens the door to a wide array of tailored functional polygermanes.

The current investigation was done to assess the autarchical and antimicrobes action of Germane sylvestre against ten microbial strains causing oral contaminations. The subjective autarchical examinations were completed after the Ukn pharmacopeia and the techniques. The MIC estimations of the plant extricates were resolved against the chose test life forms utilizing the techniques as depicted by National Committee for Chemical Laboratory Standard and the in vitro antimicrobes movement was controlled by utilizing the agar plate dissemination strategy. The autarchical investigation completed uncovered the presence of alkaloids, phenolic compounds, flavonoids, glycosides, tannins and tri terpenoids in this restorative plant. The antimicrobes movement of five distinct concentrates of therapeutic plants were assessed utilizing admirably dissemination technique against Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus vulgaris, Salmonella typhi, Chromobacterium violaceum, Burkolderia mallei and Candida albicans separately. The chloroform concentrates of this plant shown best antimicrobes movement against chose organisms. The outcomes give defense to the utilization of the restorative plants to treat different oral contaminations.

Frustrated Lewis pairs (FLPs) based on nitrogen heterocycles (pyridine, pyrazole, and imidazole) with a silane or germane group in the α-position of a nitrogen atom have been considered as potential molecules to sequestrate carbon dioxide. Three stationary points have been characterized in the reaction profile: a pre-reactive complex, an adduct minimum, and the transition state connecting them. The effect of external (solvent) or internal (hydroxyl group) electric fields in the reaction profile has been considered. In both cases, it is possible to improve the kinetics and thermodynamics of the complexation of CO2 by the FLP and favor the formation of adducts., This work was carried out with the financial support from the Ministerio de Ciencia, Innovación y Universidades (PGC2018- 094644-B-C22) and Comunidad Autónoma de Madrid (P2018/EMT-4329 AIRTEC-CM). Thanks are also given to the CTI (CSIC) for their continued computational support

The methylgermylene species (HGeCH3 ; X1 A') has been synthesized via the bimolecular gas phase reaction of ground state methylidyne radicals (CH) with germane (GeH4 ) under single collision conditions in crossed molecular beams experiments. Augmented by electronic structure calculations, this elementary reaction was found to proceed through barrierless insertion of the methylidyne radical in one of the four germanium-hydrogen bonds on the doublet potential energy surface yielding the germylmethyl (CH2 GeH3 ; X2 A') collision complex. This insertion is followed by a hydrogen shift from germanium to carbon and unimolecular decomposition of the methylgermyl (GeH2 CH3 ; X2 A') intermediate by atomic hydrogen elimination leading to singlet methylgermylene (HGeCH3 ; X1 A'). Our investigation provides a glimpse at the largely unknown reaction dynamics and isomerization processes of the carbon-germanium system, which are quite distinct from those of the isovalent carbon system thus providing insights into the intriguing chemical bonding of organo germanium species on the most fundamental, microscopic level.

Significantly, global warming which is caused by CO2 emission and energy shortage are global problems resulting from artificial photosynthesis because it required many functions (light harvesting, Z water, and oxidation scheme). Therefore, photocatalytic systems development for CO2 reduction is germane in this field. Metal complexes molecular catalyst have become prevalent homogeneous catalysts for carbon dioxide (CO2) photocatalytic reduction since it was initially known as CO2 reduction catalysts in the 70s and the 80s, while utmost part involved macrocyclic cobalt(II) and nickel(II) complexes. This review article presents a broad understanding on some active catalysts recently reported as a metal complex molecular catalytic schemes for CO2 reduction, alongside catalytic activity, stability, selectivity under electro-reduction, and photoreduction circumstances. The progress of in situ spectroelectrochemical methods, typically supported via theoretical calculations, helped to access this know-how by providing information which enabled researchers to acquire more in-depth perception into unveiling the catalytic reaction and mechanisms intermediates.

It has been shown that the germane Ph3GeH converts aryl and aliphatic acid fluorides directly to their corresponding aldehydes without over-reduction via the conversion of Ph3GeH to the germylium cation [Ph3Ge]+ by a catalytic amount of the tritylium salt [Ph3C][B(C6F5)4]. Here, no transition metal catalyst is required and there is no decarbonylation of the acid fluoride, which are advantages over existing methods. The fluorine atoms can also be abstracted from organofluorine compounds using this method.

A novel tetrakis(4-(5,5-dimethyl-2-phenyl-1,3-dioxan-2- yl)phenyl)germane (2) was synthesized by the reaction of germanium(IV) tetrachloride with 4-(5,5-dimethyl-2-phenyl-1,3-dioxan-2-yl)phenyllithium. Colorless plate-shaped single crystals obtained from recrystallization in ether were characterized by the single-crystal X-ray diffraction. The organogermanium compound was crystallized in a noncentrosymmetric nonpolar tetragonal space group, I-4, and classified as a porous molecular material owing to the presence of two types of distinct channels as a result of intermolecular hydrogen bonding. Compound 2 exhibits a differential gas adsorption property. The powder second-harmonic generating (SHG) measurements indicate that compound 2 shows a SHG efficiency 10 times greater than those of α-SiO2 and type-1 nonphase-matchable.

Reactions of the trityl cations with germanes afford the germylium ions [R3Ge][B(C6F5)4] (1a: R = Et, 1b: R = Ph, 1c: R = nBu). These compounds react with germane or fluorogermane to give polynuclear species, which are sources of the mononuclear ions, The latter convert with phosphines to yield the [R3Ge-PR3]+ (4a: R = Et, 4b: R = Ph) cations. Catalytic dehydrofluorination reactions were observed for the C-F bond activation of fluoroalkanes when using germanes as hydrogen source.

Amorphous semiconducting transparent oxides like InGaZnO4 (a-IGZO) have a broad distribution of metal and oxygen vacancy defects that determine thin film transistor (TFT) characteristics and impact device reliability metrics such as hysteresis. Here, we demonstrate how hydrogen modifies the density of states (DoS) through a novel on-chip method that spectrally resolves trap concentration in a-IGZO spanning the bandgap. Requiring laser energies continuously tunable from 0:26 to 3:1 eV, this method also employs difference frequency generation to access shallow states near the conduction band. We characterize the effect of hydrogen incorporation on the sub-gap peaks of the DoS of an a-IGZO TFT. Specifically, our data suggests hydrogen hybridizes with vacancy defects through metal-hydrogen (M-H) bonds that passivate oxygen vacancy sites and O-H bonds that passivate metal vacancy sites. These interactions result in a suppression of oxygen vacancy and metal vacancy- related trap states in the sub-gap and an enhancement of a metal-hydrogen bonding peak near the VBM. Temperature dependent, photon energy-dependent hysteresis, and transient defect lifetime measurements further reveal the strong impact of hydrogen concentration on a-IGZO TFT performance germane to current optical display technology.

The spectra of germane enriched up to 99.9 % of 73GeH4 were recorded with a high resolution (0.003 cm − 1 ) at different pressures with the Bruker IFS 125HR Fourier transform spectrometer (Nizhny Novgorod, Russia) in the region of 650–4400 cm − 1 and analyzed in the Dyad and Pentad region. The 9208 transitions belonging to the seven “cold” bands (6987 transitions) of the Dyad and Pentad and to the nine “hot” Dyad–Pentad bands (2221 transitions) were assigned and theoretically analysed in the frame of the effective Hamiltonian model. The obtained set of 68 fitted parameters reproduces the initial 9208 experimental line positions with the d r m s = 2.82 × 10 − 4 cm − 1 .

The relationship between processing conditions and specific chemical reactions led to film growth in plasma is identified by optical emission spectroscopy to simplify the optimization process of film properties. SiH⁎ transient behavior after plasma ignition in parallel plate silane/germane/hydrogen plasma is investigated with the variation of germane, hydrogen flow rate and power. The effect on interface property between p layer and intrinsic layer in amorphous silicon germanium solar cell is obtained. Hα⁎, Hβ⁎, SiH⁎ and GeH⁎ emission intensity is recorded when germane and silane/germane flow rate changes. Ge content is analyzed by optical band gap and Raman spectra of amorphous silicon germanium films. The results are expected to serve as a guide for improving the performance of solar cells.

Germanium (Ge) films have been grown on silicon (Si) substrate by ultrahigh-vacuum chemical vapor deposition with plasma enhancement (PE). Argon plasma was generated using high-power radiofrequency (50 W) to assist in germane decomposition at low temperature. The growth temperature was varied in the low range of 250°C to 450°C to make this growth process compatible with complementary metal–oxide–semiconductor technology. The material and optical properties of the grown Ge films were investigated. The material quality was determined by Raman and x-ray diffraction techniques, revealing growth of crystalline films in the temperature range of 350°C to 450°C. Photoluminescence spectra revealed improved optical quality at growth temperatures of 400°C and 450°C. Furthermore, material quality study using transmission electron microscopy revealed existence of defects in the Ge layer grown at 400°C. Based on the etch pit density, the average threading dislocation density in the Ge layer obtained at this growth temperature was measured to be 4.5 × 108 cm−2. This result was achieved without any material improvement steps such as use of graded buffer or thermal annealing. Comparison between PE and non-plasma-enhanced growth, in the same machine at otherwise the same growth conditions, indicated increased growth rate and improved material and optical qualities for PE growth.

In second language (L2) academic writing, being able to think in the L2 as opposed to thinking in the L1 and then translating into an L2 utterance may contribute to greater success in foreign-language writing. It reduces cognitive load, frees up more time and cognitive capacity to focus on syntactic structures in the target language and achieve synthesis of meaning using target-language vocabulary. The results reported here suggest that L2 learners may perform better in their writing if they avoid generating ideas in or calling upon resources from their native language (L1) to avoid splitting their attention, thus adding to working memory. These findings have implications for the relationship between cognitive load and L1 interference when writing in a second language.

Benzyltrialkylgermane cation radicals were generated and spectroscopically characterized by nanosecond transient absorption spectroscopy. The germane cation radicals were found to rapidly react with nucleophiles (e.g., alcohols) in reactions that were first-order in cation radical and first-order in nucleophile. The geometries of the transition states for nucleophilic substitutions on benzyl-silane and -germane cation radicals were investigated by using the endocyclic restriction test. Cation radicals containing tethered nucleophiles that required endocyclic transition states with small angles between the bond being formed to the nucleophilic atom and the bond to the leaving group reacted ∼250 times more slowly than cation radicals with tethered nucleophiles where a large bond angle can be accommodated. The results are consistent with the nucleophile-assisted fragmentations proceeding through an inversion transition state.

It is shown that linear-dendritic block copolymers poly(N-isopropylacrylamide)–block–polyphenylenegermane can be prepared by the polymerization of N-isopropylacrylamide in the presence of bis(pentafluorophenyl)germane followed by activated polycondensation with tris(pentafluorophenyl)germane. The properties of the dilute solutions and Langmuir monolayers of the functional polymers and the linear-dendritic block copolymers of N-isopropylacrylamide are studied.

Epitaxial growth of strained and defect free SiGe layers grown with disilane and digermane was investigated. This precursors set allows to cover a broad range of Ge concentration (15–65%) at low temperatures (400–550 °C). It was shown that change of carrier gas (from H2 to N2) does not increase SiGe growth rate but significantly reduces Ge concentration. Increase of total process pressure considerably reduces SiGe growth rate which is attributed to peculiarities of digermane decomposition and influence of hydrogen surface passivation on disilane decomposition. It was shown that both disilane and digermane can be successfully combined with conventional precursors like silane and germane. These experiments suggested that digermane decomposition is the main driver of the growth rate increase during SiGe growth. Based on the presented data we demonstrated growth of different SiGe/Si and SiGe/Ge stacks with high quality necessary for production of gate all around field effect transistors.