Treatment of SiCl with [EtN][BCl] in CHCl furnished the known products of a chloride-induced disproportionation reaction of the disilane, such as SiCl, [Si(SiCl)], and [SiCl·2Cl]. No Si-B-bonded products were detectable. In contrast, the addition of SiCl to [EtN][BICl] afforded the Si-B adduct [EtN][ISiBI]. Thus, a quantitative Cl/I exchange at the silicon atom accompanies the trihalogenosilanide formation. [EtN][ISiBI] was also accessible from a mixture of SiI, [EtN]I, and BI. According to X-ray crystallography, the anion [ISiBI] adopts a staggered conformation with an Si-B bond length of 1.977(6) Å. Quantum-chemical calculations revealed a polar covalent Si-B bond with significant contributions from intramolecular I···I dispersion interactions.
Si x Ge y alloys are emerging materials for modern semiconductor technology. Well-defined model systems of the bulk structures aid in understanding their intrinsic characteristics. Three such model clusters have now been realized in the form of the Si x Ge y heteroadamantanes [0], [1], and [2] through selective one-pot syntheses starting from Me 2 GeCl 2 , Si 2 Cl 6 , and [nBu 4 N]Cl. Compound [0] contains six GeMe 2 and four SiSiCl 3 vertices, whereas one and two of the GeMe 2 groups are replaced by SiCl 2 moieties in compounds [1] and [2], respectively. Chloride-ion-mediated rearrangement quantitatively converts [2] into [1] at room temperature and finally into [0] at 60 °C, which is not only remarkable in view of the rigidity of these cage structures but also sheds light on the assembly mechanism.
The halosilicates(II) [nBu 4 N] 2 [Si 6 Br 12 ·2Br] and [nBu 4 P] 2 [Si 6 I 12 ·2I] were prepared by mere addition of the appropriate halide salt to the corresponding disilane Si 2 X 6 (X = Br, I). In the first case, the Br 3 Si-substituted derivative [nBu 4 N] 2 [Si 7 Br 14 ·2Br] formed as a second product. We have been able to obtain single crystals of [Ph 4 P] 2 [Si 7 Br 14 ·2Br] by switching the Brsalt from [nBu 4 N]Br to [Ph 4 P]Br. All three compounds, [nBu 4 N] 2 [Si 6 Br 12 ·2Br] (monoclinic, P2 1 /c), [nBu 4 P] 2 [Si 6 I 12 ·2I] (triclinic, P1), and [Ph 4 P] 2 [Si 7 Br 14 ·2Br] (triclinic, P1) were structurally characterized by X-ray crystallography and found to form "inverse sandwich complexes", in which two Xions are located above and below a planarized Si 6 ring. The free periodated cyclohexasilane Si 6 I 12 is accessible from [nBu 4 N] 2 [Si 6 Cl 12 ·2Cl] and BI 3 (1:5 molar ratio; CH 2 Cl 2 ) via a decomplexation/halide-exchange cascade. Si 6 I 12 (monoclinic, C2/c) adopts a
A series of new mixed-substituted heteronuclear precursors with preformed Si–Ge bonds has been synthesized via a two-step synthesis protocol. The molecular sources combine convenient handling with sufficient thermal lability to provide access to group IV alloys with low carbon content. Differences in the molecule–material conversion by chemical vapor deposition (CVD) techniques are described and traced back to the molecular design. This study illustrates the possibility of tailoring the physical and chemical properties of single-source precursors for their application in the CVD of Si1–x Ge x coatings. Moreover, partial crystallization of the Si1–x Ge x has been achieved by Ga metal-supported CVD growth, which demonstrated the potential of the presented precursor class for the synthesis of crystalline group IV alloys.
Si1−xGex nanowires (NWs) were prepared by gold-supported chemical vapor deposition (CVD) using a single-source precursor with preformed Si–Ge bonds. Besides the tamed reactivity of the precursor, the approach reduces the process parameters associated with the control of decomposition characteristics and the dosing of individual precursors. The group IV alloy NWs are single crystalline with a constant diameter along their axis. During the wire growth by low pressure CVD, an Au-containing surface layer on the NWs forms by surface diffusion from the substrate, which can be removed by a combination of oxidation and etching. The electrical properties of the Si1−xGex/Au core-shell NWs are compared to the Si1−xGex NWs after Au removal. Core–shell NWs show signatures of metal-like behavior, while the purely semiconducting NWs reveal typical signatures of intrinsic Si1−xGex. The synthesized materials should be of high interest for applications in nano- and quantum-electronics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.