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Amorphous Silicon: New Insights into an Old Material
Author(s) -
Spomer Natalie,
Holl Sven,
Zherlitsyna Larissa,
Maysamy Fariba,
Frost Andreas,
Auner Norbert
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201404966
Subject(s) - silicon , silanes , chemistry , yield (engineering) , diglyme , trimethylsilyl , reagent , methanol , hydrogen , amorphous solid , silane , chemical engineering , organic chemistry , inorganic chemistry , materials science , solvent , engineering , metallurgy
Amorphous silicon is synthesized by treating the tetrahalosilanes SiX 4 (X=Cl, F) with molten sodium in high boiling polar and non‐polar solvents such as diglyme or nonane to give a brown or a black solid showing different reactivities towards suitable reagents. With regards to their technical relevance, their stability towards oxygen, air, moisture, chlorine‐containing reaction partners RCl (R=H, Cl, Me) and alcohols is investigated. In particular, reactions with methanol are a versatile tool to deliver important products. Besides tetramethoxysilane formation, methanolysis of silicon releases hydrogen gas under ambient conditions and is thus suitable for a decentralized hydrogen production; competitive insertion into the MeOH versus the MeOH bond either yields H‐ and/or methyl‐substituted methoxy functional silanes. Moreover, compounds, such as Me n Si(OMe) 4− n ( n =0–3) are simply accessible in more than 75 % yield from thermolysis of, for example, tetramethoxysilane over molten sodium. Based on our systematic investigations we identified reaction conditions to produce the methoxysilanes Me n Si(OMe) 4− n in excellent ( n =0:100 %) to acceptable yields ( n =1:51 %; n =2:27 %); the yield of HSi(OMe) 3 is about 85 %. Thus, the methoxysilanes formed might possibly open the door for future routes to silicon‐based products.