Dodecamethoxyneopentasilane as a New Building Block for Defined Silicon Frameworks

Abstract

In this contribution, a convenient synthetic method to obtain tris(trimethoxysilyl)silanides (M=Li, Na, K, Cu) 5 a–d is described. 5 a–d are easily accessible deriving from dodecamethoxyneopantasilane 4 in excellent yields and could be fully characterized via NMR spectroscopy and X‐ray crystallography. The efficiency of 5 a–d to serve as a new building block in silicon chemistry is demonstrated by the reactions with two different types of electrophiles (carbon‐ and silicon‐electrophiles). In all cases the salt metathesis reaction gave rise to novel polysilanes in excellent yields. The possibility of a post‐functionalization to perhydropolysilanes as well as perchloropolysilanes enables the synthesis of new precursors for silicon deposition.

Molecular Main Group Metal Hydrides

“…The structures of both linear [SiH 2 ] n and [GeH 2 ] n have been modelled computationally, leading to estimated HOMO-LUMO gaps of 3.9 and 3.3 eV, respectively. , The properties associated with σ-electron delocalization within polysilanes [SiR 2 ] n were reviewed in 2003 . An efficient route to the branched polysilane (H 3 Si) 3 Si-SiMe 3 was reported recently, and this species represents a promising precursor to bulk silicon . Extended tetrelane hydrides containing both Si and Ge centers (e.g., the butane analogue H 3 Ge-SiH 2 –SiH 2 –GeH 3 ) have been developed for CVD, − while the deposition of bulk or nanodimensional Ge from volatile germanium hydrides remains an active field of study post-2001. − While distannane H 3 Sn-SnH 3 has been prepared, this species is too thermally unstable to be used in a reliable fashion for materials synthesis. , As a result, SnH 4 and its deuterium analogue SnD 4 are commonly employed as part of synthetic protocols to access tin-containing solid state compounds, such as ternary Si x Ge y Sn z semiconductors of controllable composition. − …”

“…952 An efficient route to the branched polysilane (H 3 Si) 3 Si-SiMe 3 was reported recently, and this species represents a promising precursor to bulk silicon. 953 Extended tetrelane hydrides containing both Si and Ge centers (e.g., the butane analogue H 3 Ge-SiH 2 −SiH 2 − GeH 3 ) have been developed for CVD, 954−958 while the deposition of bulk or nanodimensional Ge from volatile germanium hydrides remains an active field of study post-2001. 959−963 While distannane H 3 Sn-SnH 3 has been prepared, this species is too thermally unstable to be used in a reliable fashion for materials synthesis.…”

Synthesis and Characterization of Methoxylated Oligosilyl Group 4 Metallocenes

“…The quaternary silicon signal for compound 2 shows a significant low-field shift when compared to 3 and 4 , whereas the signals for the − Si (OMe) 3 groups adopt only a slight change in the shifts. By comparison of the 29 Si NMR signals of compounds 1c ( 34 ) and 2 – 4 , we found a significant high-field shift for central silicon signals, indicating the deshielding of the silicon atoms based on the formation of a Si–M (M = Ti, Zr, Hf) bond. All other analytical and spectroscopic data that support the structural assignments are given in the Experimental Section together with experimental details.…”

“…The unsuccessful isolation of the bis-silylated metallocenes with the usage of 2 equiv of 1c encouraged us to investigate the reactivity of another silanide. Therefore, 1,1,1,6,6,6-hexamethoxy-3,3,4,4-tetramethyl-2,2,5,5-tetrakis(trimethoxysilyl)-hexasilane was synthesized according to published procedures 34 and used for the synthesis of the dianion 8 shown in Scheme 6 .…”

“…Due to the fact that no significant correlation between the used silanide and the yield of the expected product was observed, only 1c was used as nucleophile. 34 …”