Diborane toxicity

Chemical Reactivity - Reactivity with Water Reacts to form flammable hydrogen gas Reactivity with Common Materials Reacts with acids to form toxic, flammable diborane gas. Slowly attacks and destroys glass Stability During Transport Stable unless contaminated with acids or is overheated, thereby forming flammable hydrogen gas Neutralizing Agents for Acids and Caustics Caustic formed by the reaction with water can be diluted with water and then neutralized with acetic acid Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Reductions with diborane have been investigated by Brown and his co-workers. Diborane is an inflammable toxic gas which is available commercially or may be generated by the reaction of sodium borohydride and... 

A major disadvantage of CVD (as opposed to PVD) is that many precursors are toxic and in some cases lethal even at low concentration (for instance nickel carbonyl, diborane, arsine, and phosphine). Some are also pyrophoric, such as silane, some alkyls, arsine, and phosphine. Very often the reaction is not complete and some of the precursor materials may reach the exhaust unreacted. In addition, many of the by-products of the reaction are also toxic and corrosive. This means that all these effluents must be eliminated or neutralized before they are released to the... 

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

Most of the gases used are hazardous they can be corrosive, flammable, explosive, and/or highly toxic. Silane is pyrophoric the dopant gases diborane, phos-... 

Safety considerations are paramount in any boron hydride synthesis. The energy yield from the oxidations of boron hydrides is too high for any cavalier treatment of boron hydrides. Exclusion of air is the critical consideration in diborane reactions. Decaborane(14) is less reactive, generally, in a kinetic sense, but the thermodynamic potential is comparable. In addition, all volatile boron hydrides are toxic. The procedures described in the latter two preparations are within our experience non-hazardous. These procedures should be followed in every detail improvisation is not recommended. 

Hydroborations have to be carried out with some care, because diborane and many alkylboranes are highly reactive and toxic substances many are spontaneously flammable in air. 

TEB (Triethylborane, Triethylborine or Boron Triethyl). (C2HS)3B mw 98.13 colorl pyrophoric liq mp —93° bp 95° d 0.6961g/cc at 23° RI 1.3971. Miscible with most org solvents immiscible with w. Prepn is by dropwise addn of an n-butyl eth soln of BF3 to a soln of ethyl Mg bromide in n-butyl eth. Upon completion of the reaction the prod is distld off at 95° under N2. Also, by the reaction of triethyl Al with B halide, or diborane with ethylene. TEB has a flash pt of 0° a Qc of 20000BTU/lb and, according to Sax (Ref 4), a high vap toxicity... 

These have the major advantage of being safe, as contrasted to the very toxic phosphine and diborane. 

It should be noted that the diborane (a highly toxic gas, spontaneously flammable in air) expected from the stoichiometric equation... 

Diborane is an inconvenient reagent. It is a toxic, flammable, and explosive gas. It is more easily used as a complex with tetrahydrofuran (THF), a cyclic ether. This complex reacts like diborane, yet the solution is easily measured and transferred. 

Complexes with Electrophiles An ether s nonbonding electrons also stabilize borane, BH3. Pure borane exists as a dimer called diborane, B2H6. Diborane is a toxic, flammable, and explosive gas, whose use is both dangerous and inconvenient. Borane forms a stable complex with tetrahydrofuran. The BH3 THF complex is commercially available as a 1 M solution, easily measured and transferred like any other air-sensitive liquid reagent. The availability of BH3 THF has contributed greatly to the convenience of hydroboration (Section 8-7). 

Boron trifluoride is used as a Lewis acid catalyst in a wide variety of reactions. Like diborane, BF3 is a toxic gas, but BF forms a stable complex with ethers, allowing it to be conveniently stored and measured. The complex of BF3 with diethyl ether is called boron trifluoride etherate. ... 

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. 

Use and exposure Diborane is a colorless gas at room temperature with a repulsive, sweet odor. It mixes well with air and easily forms explosive mixtures. Diborane will ignite spontaneously in moist air at room temperature and can cause explosions. Diborane is used in rocket propellants and as a reducing agent, a rubber vulcanizer, a catalyst for hydrocarbon polymerization, a flame-speed accelerator, and a doping agent. Diborane is a very toxic and flammable gas used by chemists to make other compounds. It is also used in electronics to impart electrical properties in pure crystals. Industrial workers are exposed to diborane by breathing in its vapors in work areas. - ... 

Toxicity and health effects Diborane is a poisonous gas. Industrial workers exposed to diborane show sensations of tightness of the chest, diaphragmatic pain, shortness of breath, cough, and wheezing. These signs and... 

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. ... 

Agency for Toxic Substances and Disease Registry (ATSDR). 2002. Managing hazardous materials incidents. Volume III—Medical management guidelines for acute chemical exposures Diborane (updated 2007). Atlanta, GA U.S. Department of Health and Human Services, Public Health Service. 

Bulk aluminum may undergo the following dangerous interactions exothermic reaction with butanol, methanol, 2-propanol, or other alcohols, sodium hydroxide to release explosive hydrogen gas. Reaction with diborane forms pyrophoric product. Ignition on contact with niobium oxide + sulfur. Explosive reaction with molten metal oxides, oxosalts (nitrates, sulfates), sulfides, and sodium carbonate. Reaction with arsenic trioxide + sodium arsenate + sodium hydroxide produces the toxic arsine gas. Violent reaction with chlorine trifluoride, Incandescent reaction with formic acid. Potentially violent alloy formation with palladium, platinum at mp of Al, 600°C. Vigorous dissolution reaction in... 

When pure (dry) it does not attack glass or mercury at normal temperatures. Can react violently with NH3, CO, diborane, H2, H2S, CH4, tetrafluorohydrazine. Can react vigorously with reducing materials. Particularly hazardous under pressure. Incompatible with charcoal, hydrogen-containing compounds, tetrafluorohydrazine. When heated to decomposition it emits highly toxic fumes of F. See also FLUORIDES. 

SAFETY PROFILE Moderately toxic by inhalation. A severe eye, skin, and mucous membrane irritant. Explodes on contact with dioxygen difluoride. Violent reaction or ignition with borane, diborane, F2. hexafluoroisopropylideneamino lithium, O2. Win react with water or steam to produce toxic and corrosive fumes. Dangerous when heated to decomposition it emits highly toxic fumes of F" and PO. See also HYDROFLUORIC ACID, FLUORIDES, and PHOSPHORUS PENTAFLUORIDE. 

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. 

The gas is highly toxic by inhalation, and the nose cannot be depended upon to warn of unsafe concentrations (diborane temporarily deadens the olefactory senses). Although pure diborane is not spontaneously flammable in air at room temperature, it should always be assumed to contain decomposition products which can make it spontaneously flammable. 

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. 

Octahydrotriborate (1 — )ion, [B3H8], is an important intermediate in the synthesis of higher boranes, polyhedral borane anions, and transition-metal complexes. Salts containing this ion have usually been prepared1 from diborane, which is toxic, spontaneously flammable, and expensive. In addition, pressure facilities are often required for the synthesis. 

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. 

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