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Dehydrocoupling of tris(hydridosilylethyl)boranes with ammonia or amines: a novel route to Si–B–C–N preceramic polymers
Author(s) -
Weinmann Markus,
Nast Sabine,
Berger Frank,
Kaiser Gerhard,
Müller Klaus,
Aldinger Fritz
Publication year - 2001
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.240
Subject(s) - chemistry , thermogravimetric analysis , amorphous solid , methylamine , thermal decomposition , infrared spectroscopy , ammonia , boranes , thermogravimetry , ceramic , boron , polymer chemistry , nuclear chemistry , crystallography , inorganic chemistry , organic chemistry
The synthesis of boron‐modified polysilazanesof general type {B[C 2 H 4 Si(R)NR′] 3 } n [R = CH 3 , (NR′) 0.5 ; R′ = H, CH 3 ] by dehydrogenative coupling of tris(hydridosilylethyl)boranes B[C 2 H 4 Si(CH 3 ) n H 3− n ] 3 (C 2 H 4 = CHCH 3 , CH 2 CH 2 ; n = 0, 1) and ammonia or methylamine is reported. Detailed characterization of the title compounds was performed using spectroscopic methods such as solid‐state NMR spectroscopy, IR spectroscopy, and elemental analysis. Thermolysis produces amorphous Si–B–C–N ceramics with ceramic yields between 25 and 83%, as determined by thermogravimetric analysis (TGA) in argon. High‐temperature TGA in an argon atmosphere reveals that a number of the ceramics obtained resist degradation up to ∼2000 °C. X‐ray diffraction studies of the as‐obtained amorphous materials show formation of α‐SiC or α‐SiC/β‐Si 3 N 4 crystalline phases between 1600 and 1800 °C, depending on the composition of the materials. Copyright © 2001 John Wiley & Sons, Ltd.