Potassium Borohydride, Ammonia-Borane, Borazine, and Polyborazylene for Researchers in Industries and Universities

Potassium Borohydride
Potassium borohydride is a well known reducing agent. It has numerous uses in the preparation of pharmaceuticals, as a pulp bleach and in the recovery of noble metals. There have been some recently reported novel uses of potassium borohydride. Order Potassium Borohydride >

Novel uses of potassium borohydrideA few examples are cited here.

KBH₄ has been found to be a novel electron injection material for organic light-emitting diodes.¹

Quartz optical fibers are a new type of intelligent material being used for sensors with many applications. KBH₄ can be used in an electroless Ni-P-B plating of quartz optical fibers.²

KBH₄ has been used to prepare composite electrodes for electrochemical supercapacitors. In this application, manganese dioxide and Ag-doped manganese dioxide powders were prepared using KBH₄ as a reducing agent. The powders were then used with other reagents to form current collectors.³

A simple method using KBH₄ has been used to encapsulate Co nanocrystallites in boron nitride shells. The synthesis of stable metal nanoparticles has many practical applications in the optical, magnetic and catalytic fields.⁴

KBH4 can be used in a direct borohydride fuel cell. The application makes use of perovskite-type oxide LaNiO₃/C-catalysed cathode.⁵

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. Order Ammonia-Borane >

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. Order Borazine >

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.

Order Polyborazylene >

___________________________________________________________________________

[1]   Liu Q, Zhang D, Duan L, Zhang G, Wang L, Cao Y, Qiu Y. Thermally Decomposable KBH4 as an Efficient Electron Injection Material for Organic Light-Emitting Diodes. Japanese Journal of Applied Physics 2009; 48:080205-1-3.
[2]   Jiang B, Xiao L, Hu S, Peng J, Zhang H, Wang M. Optimization and kinetics of electroless Ni-P-B plating of quartz optical fiber. Optical Materials 2009; 31:1532-39.
[3]   Jacob GM, Yang QM, Zhitomirsky I. Composite electrodes for electrochemical supercapacitors. J Appl Electrochem 2009; 39:2579-85.
[4]   Calderon-Moreno JM, Pradell T, Crespo D, Popa M, Narita I, Oku T. Cobalt nanocrystallites encapsulated in boron nitride shells. Materials Science and Engineering B 2009; 162:106-10.
[5]   Ma J, Liu Y, Liu Y, Yan Y, Zhang P. A Membraneless Direct Borohydride Fuel Cell Using LaNiO3-Catalysed Cathode. Fuel Cells 2008; 0:394-8.