Über die verbesserte Darstellung von Silyl‐ und Germylkalium sowie die Synthese von Silylgermanen

Abstract

An Improved Preparation of Silyl‐ and Germylpotassium and Synthesis of Silylgermanes The preparation of KSiH3 and KGeH3 is improved, and several syntheses of silylgermane, H3Si – GeH3, are described. A series of other potential processing gases for PE‐CVD is prepared: H3Ge – SiR1R2R3 (R1, R2, R3 = H, H, Me; H, H, Et; H, H, tBu; H, H, Ph; H, Me, Me; Et, Et, Et; H, Me, Ph; H, Me, GeH3). A new method for the preparation of silylgermanes by the reaction of silyl esters of sulfonic acids (RSO3H, R = C4,F9, Me, Ph) with KGeH3 is reported.

Tris(trichlorosilyl)tetrelide Anions and a Comparative Study of Their Donor Qualities

“…Oligosilanes are precursors in the chemical vapor deposition (CVD) of amorphous Si‐based materials for use in thin‐film solar cells. The spectrum of absorbed light can be widened to shorter or longer wavelengths through the incorporation of C or Ge atoms, respectively . Yet, the simultaneous deposition of individual silanes and germanes suffers from separation effects, which lead to Si‐ and Ge‐enriched areas and thereby reduce the photovoltaic efficiency of the device.…”

“…[27] Differences in the bond orders between the CÀSi bond and the (Si/Ge)ÀSi bonds of [1] À -[3] À also become evident from the resonances of the SiCl 3 moieties in the 29 Si NMR:[ 1] À resonates at d( 29 Si) = À10.9 ppm, whereas the signals of [2] À and [3] À are detected at lower field strengthsw ith almost identical chemicals hiftv alues of d( 29 Si) = 29.5 and 29.7 ppm, respectively.I nt he case of [1·GaCl 3 ] À versus [1] À ,t he SiCl 3 resonance undergoes ad ownfield shift to d( 29 Si) = À3.4 ppm (cf. H [1]: À2.6 ppm). [18] The resonances of the other two adducts experi- [19] and 11.3 ppm ([3·GaCl 3 ] À ).…”

“…The spectrum of absorbed light can be widened to shorter or longerw avelengthst hrough the incorporationo fC or Ge atoms, respectively. [1] Yet, the simultaneousd eposition of individual silanes and germanes suffers from separation effects, which lead to Si-and Ge-enriched areas and thereby reduce the photovoltaic efficiency of the device. Mixed-element precursors containingS ia nd Ge covalently linked to each other offer as olution to the problem,b ut the number of available compounds is very limited.…”

“…Georg 4 Ge, whicha re relevant for the preparation of singlesource,mixed-element CVD precursorss uch as (H 3 Si) 4 Ge. The methanide [1] À is accessible in > 90 %y ield from CCl 4 and in situ generated[ SiCl 3 ] À (Scheme 1). [18] The silanide [2] À was first identified on the basis of 29 Si NMR spectroscopy [13] and later structurally characterizedb yB eckmann, Ketkov,a nd Mebs, [19] who isolated [2] À as as ide product of the synthesis of SiCl 2 (IDipp).…”

Selective Synthesis and Derivatization of Germasilicon Hydrides

“…Sundermeyer et al synthesized the silylgermanes (H 3 Si) 2 GeH 2 , (H 3 Si) 3 GeH, and (H 3 Si) 4 Ge from the corresponding silylgermanides (H 3 Si) x GeH 4– x Na ( x = 2–4) and C 4 F 9 SO 3 SiH 3 and isolated the individual products by preparative gas chromatography . The same group presented an alternative approach to H 3 GeSiH 3 by halodephenylation of H 3 GeSiH 2 Ph with anhydrous HBr followed by hydrogenation of the bromosilane intermediate with LiAlH 4 . Hoefler et al, finally, investigated the reaction of Ph 3 GeSiPh 3 with excess anhydrous HCl or HBr and observed the predominant scission of the Si–Ge bond .…”