Borazine, Polyborazylene
and Ammonia-Borane for Researchers
in Industries and Universities
All 3 products are supplied from 10g to Kg Quantities
Borazine
Borazine, (HBNH)3, is isoelectronic
with benzene and sometimes referred
to as inorganic benzene. It is
a colorless liquid and indeed
shows striking physical properties
similar to borazine. For reviews
on borazines, see Chapter III,
The Borazines in Boron-Nitrogen
Compound, K. Niedenzu and J.W.Dawson:
Academic Press Inc., New York,1965
and The Borazines, 259-305 in
Advances in Inorganic Chemistry
and Radiochemistry, Vol 5, Academic
Press Inc. , New York, 1963. Borazine
melts at -56.2 C and boils at
55 C. It has neglible decompostion
at or below 0 C but slowly decomposes
at room temperature. Extensive
decomposition occurs after three
months at ambient temperature
and therefore should always be
stored in the freezer. Borazine
is stable in dry air but reacts
with moisture in air. It reacts
slowly with water at ambient temperature
to form boric acid, ammonia and
hydrogen gas. The density of borazine
at the melting point is 1.00g/ml
and at the boiling point, 0.81g/ml.
The vapor pressure at 0 C is 84.8
mm Hg. An MSDS is available upon
request.
Polyborazylene
Polyborazylene appears to have a complex structure with linear, branched -chain and fused-cyclic segments. The polymer is soluble in ether solvents such as dimethoxy ethane (glyme) and THF. The polymer is moisture sensitive and precautions to avoid exposure to moisture must be taken. Polyborazylene is a high-yield precursor to boron-nitride and more information is available in the publication Synthesis, Properties, and Ceramic Conversion Reactions of Polyborazylene. A High-Yield Polymeric Precursor to Boron-Nitride Chem. Mater., Vol 7, No10, 1995.
Ammonia-Borane
Ammonia-Borane is a white crystalline substance containing 19.5% hydrogen and has been the subject of considerable interest as a solid material for hydrogen generation. The stability of ammonia-borane has generated some controversy and seems to be dependent upon purity. Recently it has been reported that incorporation of ammonia-borane in a mesoporous silica material may facilitate release of hydrogen from the material [Nanoscaffold Mediates Hydrogen Release and the Reactivity of Ammonia-Borane A. Gutowska, et al. Angew. Chem. Int.Ed. 2005, 44, 3578-3582.] BoroScience Canada, Inc supplies ammonia-borane for furthur R&D studies on this material. The Ammonia-Borane supplied by us is 99% pure.
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