Diborane caution

When the evaporation is complete, the 0°C. trap will contain a few milliliters of diglyme the — 196°C. trap will have trapped-out diborane (caution) and the — 126°C. trap will have retained the dimethyltin dihydride together with traces of diglyme and diborane. The crude product is accordingly subjected to a second vacuum fractionation through clean, 0°C. and — 126°C. vacuum traps into the same — 196°C. trap. The diborane collected in the — 196°C. trap is destroyed as described in Sec. A. The colorless, volatile liquid product is identified from its vapor-phase infrared spectrum14 and from its refractive index, nf> 1.4475, literature,2 n 1.4480, as dimethyltin dihydride. The yield is 8.25 g. (0.055 mole, 96%). 

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

Caution. Diborane(6) and l-methyldiborane(6) inflame explosively on contact with the atmosphere, and methyllithium may inflame on exposure to moist air. 

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. 

Caution. Since both tertiary phosphines and diborane-(6) are toxic, and since diborane-(6) is spontaneously flammable in air, all operations should be carried out in an argon or nitrogen atmosphere and in a well-ventilated hood. 

Caution. The gas evolved during the reaction contains some diborane(6) and hydrogen and is therefore poisonous and potentially explosive. It should be vented from the bubbler to a fume hood. When treated in this manner the dangerous gases are diluted and present no hazard. 

Caution Carry out all procedures in a well-ventilated hood, and wear disposable vinyl or latex gloves and chemical-resistant safety goggles. Diborane is a flammable and highly irritating compound. 

Fill the syringe with 100 mL diborane in THF from the bottle containing this solution (see Fig. 5.5). Caution (a) support the bottle containing the diborane solution by a clamp (b) this operation should be made with great... 

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) and other borane species in the vacuum line trap may be diluted with nitrogen and vented into a solution of pyridine in benzene for safe disposal. Alternatively, pyridine may be condensed in the vacuum-line trap. 

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. 

Caution. Diborane and pentaborane are toxic and spontaneously inflame or explode in air. The reaction should be carried out with strict exclusion of air in a shielded apparatus in an efficient fume hood. 

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 is extremely hazardous and can explode violently on contact with the atmosphere. Syntheses using B2H, should be attempted only by persons well versed in nonatmospheric techniques. 

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

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