Diborane handling

For additional information on the safe storage and handling of diborane, see the Callery Chemical Company publication entitled Diborane Handling Bulletin [1]. 

Diborane Handling Bulletin, 1982, Gallery Chemical Company, P.O. Box 429, Pittsburgh, PA 15230. 

Sodium borohydride reacts with boron halides to form diborane [19287-45-7] 2 6 more conveniendy handled as the monomer... 

CAUTION Diborane is a toxic gas which bums explosively in air. Its handling requires adequate precautions . 

Great care must be used in handling diborane and alkylboranes because they ignite spontaneously in air (with a green flame). The solution of THF BH3 is considerably less prone to spontaneous ignition but still must be used in an inert atmosphere and with care. 

A boron analog - sodium borohydride - was prepared by reaction of sodium hydride with trimethyl borate [84 or with sodium fluoroborate and hydrogen [55], and gives, on treatment with boron trifluoride or aluminum chloride, borane (diborane) [86. Borane is a strong Lewis acid and forms complexes with many Lewis bases. Some of them, such as complexes with dimethyl sulfide, trimethyl amine and others, are sufficiently stable to have been made commercially available. Some others should be handled with precautions. A spontaneous explosion of a molar solution of borane in tetrahydrofuran stored at less than 15° out of direct sunlight has been reported [87]. 

Borazine has been known since the pioneering work of Alfred Stock early in this century. Stock s work was important in two regards He was the first to study compounds such as the boranes. silanes, and other similar nonmetal compounds, and he perfected vacuum line techniques for the handling of au- and moisture-sensitive compounds, invaluable to the modern inorganic chemist.67 Stock synthesized borazine by heating the adduct of diborane and ammonia 66... 

Caution. Diborane(6) is a highly toxic, extremely flammable gas (bp — 86.5°). Serious explosions have resulted from exposure of diborane(6) to atmospheric oxygen. All apparatus to be used for handling diborane(6) should be checked carefully for leaks. Suitable safety shields should be employed. 

Caution. Diborane(6) reacts explosively with atmospheric oxygen and is extremely toxic. This highly volatile substance must be handled in a vacuum line at all times. The pyrolysis bulb must be inspected as detailed in the synthesis o/[(CH3)2NBH2]2 (p. 32). The aminoboranes should be regarded as toxic. 

Precautions Diborane is a highly toxic, flammable, and reactive gas. It is spontaneously combustible in moist air and may burn or explode upon contact with halogenated compounds. It explodes on contact with fluorine, chlorine, halogenated hydrocarbons, fuming nitric acid, and nitrogen trifluoride. It is a very dangerous gas and must be handled and used only in chemical laboratories by experienced and trained professional workers. ... 

Borane (BH3) is a reactive gas that exists mostly as the dimer, diborane (B2H6). Borane is a strong Lewis acid that reacts readily with Lewis bases. For ease in handling in the laboratory, it is commonly used as a complex with tetrahydrofuran (THF). 

Caution. This synthesis is not suitable for the preparation of diborane in a flow system at atmospheric pressure because flaming of the reaction mixture and for the formation of unwanted reduction products (i.e., phosphine) may occur. Inasmuch as diborane reacts violently with oxygen and is extremely poisonous, it must be handled either in a vacuum line or an oxygen-free reaction system at all times. 

Caution. Diborane(6) is a very toxic, flammable, and ill-smelling gas. It has an autoignition tempeature of 38 to 52°C. Some people cannot smell diborane(6) for those individuals, the handling of this compound may be especially dangerous. All work with diborane(6) must be carried out in a well-ventilated fume hood. 

Diborane, B2Hg, is a gas and is difficult to handle. However, borane complexed with donors such as THE or dimethylsulfide are commercially available and have become valuable reagents for the reduction of various functional groups. BHg SMc2 is soluble in and unreactive toward a wide variety of aprotic solvents such as THE, Et20, CH2CI2, and hydrocarbons. 

Diborane is valued as a fuel for use in rocket propellants. Gallery Ghemical Co. developed equipment and procedures for the safe handling of diborane and by 1962 had produced about 5 million pounds of the material. It is offered for shipment in chrome-molybdenum steel cylinders at —80° (minimum order 100 g.), and technical bulletins present information on handling procedures and safety precautions. 

Diborane is extremely toxic. It is an extremely reactive gas and hence should be handled in a special apparatus. Moreover, a serious drawback to using diborane is that the boron-containing product of combustion is a solid, B2O3. If an internal combustion engine is used, the solid will eventually coat the internal surfaces, increasing friction, and will clog the exhaust valves. 

Caution. The characteristically disagreeable-smelling diborane is very toxic. Ethyl- and propyldiboranes are likewise foul-smelling and extremely sensitive to air and moisture. These spontaneously flammable compounds as well as triethyl- and tripropylboranes must be handled and stored under an inert gas such as pure nitrogen or pure argon. 

Caution Diborane and substituted diboranes are extremely hazardous materials and should be handled only by persons experienced in nonatmospheric techniques. 

Diborane should be handled using the "basie prudent practices" of Chapter 5.C, supplemented by the additional precautions for work with reactive and explosive compounds described in Chapter 5.G. In particular, diborane should be used only in a fume hood free of ignition sources and should be stored in a cold, dry, weU-ventUated area separated from incompatible substances and isolated from sources of sparks and open flames. 

Excess diborane and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution s waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume. ... 

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