19287-45-7 Usage
Chemical Properties
Diborane is a compressed, colorless, and flam-
mable gas. It has a nauseating, sickly sweet odor.
Uses
Different sources of media describe the Uses of 19287-45-7 differently. You can refer to the following data:
1. Diborane is used as a rocket propellant, in thevulcanization of rubber, as a polymerizationcatalyst, as a reducing agent, in the synthesisof trialkyl boranes, and as a doping agent(Merck 1996).
2. Diborane is commonly used in the electronics
industry for semiconductor doping by mixing
small concentrations with silane in the gas phase
prior to decomposition. When reacted with
silane and oxygen, diborane also produces the
cladding layers of wave guides for fiber optics
by chemical vapor deposition.
Other uses of diborane include the preparation
of boron nitride by the reaction of diborane
with ammonia, as a catalyst for polymerization,
and for the conversion of olefins to trialkyl boranes.
It is also used in the conversion of amines
to amine boranes and as a selective reducing
agent with carbonyl compounds such as aldehydes
and ketones to form alcohols.
3. As catalyst for olefin polymerization; as rubber vulcanizer; as reducing agent; as flame-speed accelerator; in rocket propellants; in intermediate in preparation of the boron hydrides; in conversion of olefins to trialkylboranes and primary alcohols; as a doping gas.
Air & Water Reactions
Highly flammable. Ignites spontaneously in moist air (forms hydrogen and boric acid), [Haz. Chem. Data (1966)]. Oxygen and Diborane form spontaneously explosive mixtures, [J. Amer. Chem. Soc. 76, 1997(1954)].
Reactivity Profile
Diborane is a colorless, air and moisture-sensitive gas, highly toxic. Diborane ignites in air. Diborane is very explosive when exposed to heat or flame, on contact with moisture Diborane produces hydrogen gas. Explosive reaction with benzene vapor, chlorine, nitric acid and tetravinyllead [Bretherick, 5th ed., 1995, p. 77]. Explosive reaction with dimethyl sulfoxide [Shriver, 1969, p. 209], violent reaction with halocarbon liquids used as fire extinguishants (e.g., carbon tetrachloride). Reaction with Al or Li produces complex hydrides that may ignite spontaneously in air [Haz. Chem. Data, 1975, p. 114].
Hazard
Diborane is pyrophoric and will ignite upon exposure to air. The boiling point is ?135°F and the flammable range is 0.8%–88% in air. The ignition temperature is 100° (37°C) to 140°F (60°C), and the flash point is 130°F (54°C). Diborane will react violently with halogenated fire-extinguishing agents, such as the halons. The four-digit UN identification number is 1911. The NFPA 704 designation is health 4, flammability 4, and reactivity 3. The white section of the diamond has a W with a slash through it, indicating water reactivity.
Health Hazard
Different sources of media describe the Health Hazard of 19287-45-7 differently. You can refer to the following data:
1. Animal studies indicate that exposure todiborane results in irritation and possibleinfection in respiratory passage. In additionto the acute poisoning of the lungs, this gasmay cause intoxication of the central nervoussystem. A 4-hour exposure to 60 ppm maybe lethal to mice, resulting in death frompulmonary edema.
2. Boranes are highly toxic by inhalation, skin absorption or ingestion. They may produce acute or chronic poisoning. Diborane is an irritant to the lungs and kidneys. The primary effect of Diborane poisoning is lung congestion caused by local tissue irritation produced by the exothermic reaction of hydrolysis.
3. Inhalation of diborane gas results in irritation of the respiratory tract and may result
in headache, cough, nausea, difficulty in breathing, chills, fever, and weakness. The
odor of diborane cannot be detected below the permissible exposure limit, so this
substance is considered to have poor warning properties. Overexposure to diborane
can cause damage to the central nervous system, liver, and kidneys. Death can result
from pulmonary edema (fluid in the lungs) and/or from lack of oxygen. Exposure to
diborane gas has not been found to have significant effects on the skin and mucous
membranes, but high concentrations can cause eye irritation, and contact with the
liquid can cause burns.
Chronic exposure to low concentrations of diborane may cause headache,
lightheadedness, fatigue, weakness in the muscles, and tremors. Repeated exposure
may produce chronic respiratory distress, particularly in susceptible individuals. An
existing dermatitis may also be worsened by repeated exposure to the liquid.
Diborane has not been shown to have carcinogenic or reproductive or developmental
effects in humans.
Fire Hazard
Different sources of media describe the Fire Hazard of 19287-45-7 differently. You can refer to the following data:
1. Diborane is a flammable gas that ignites spontaneously in moist air at room
temperature and forms explosive mixtures with air from 0.8% up to 88% by volume.
Diborane reacts with halogenated hydrocarbons, and fire extinguishing agents such
as Halon or carbon tetrachloride are therefore not recommended. Carbon dioxide
extinguishers should be used to fight diborane fires. Fires involving diborane
sometimes release toxic gases such as boron oxide smoke.
2. Diborane will ignite spontaneously in moist air at room temperature. Also, Diborane reacts violently with vaporizing liquid-type extinguishing agents. Diborane hydrolyzes in water to hydrogen and boric acid. Incompatible with air, halogenated compounds, aluminum, lithium, active metals, oxidized surfaces, chlorine, fuming nitric acid, nitrogen trifluoride, oxygen, and phosphorus trifluoride. Avoid moist air, electrical sparks, open flames or any other heat source. Hazardous polymerization may occur.
Flammability and Explosibility
Diborane is a flammable gas that ignites spontaneously in moist air at room temperature and forms explosive mixtures with air from 0.8% up to 88% by volume. Diborane reacts with halogenated hydrocarbons, and fire extinguishing agents such as Halon or carbon tetrachloride are therefore not recommended. Carbon dioxide extinguishers should be used to fight diborane fires. Fires involving diborane sometimes release toxic gases such as boron oxide smoke.
Materials Uses
Common metals are suitable as materials of
construction. These include the following metals
and metal alloys: chrome-molybdenum steel,
Type 300 stainless steel, brass, lead, Monel,
K-Monel, and nickel. Piping and appurtenances
for undiluted diborane must be designed by
experienced engineers and safety and fire protection specialists. Saran, polyethylene, Kel-F,
Teflon, graphite, and high-vacuum silicone
grease are satisfactory for use with diborane.In addition to the ability of a material to withstand
chemical attack, the evaluation of materials
compatibility with diborane should also emphasize
the effect of the material on diborane
stability (as expressed by the decomposition
rate). The use of the following materials is not
recommended:
? Metal oxides
? Natural rubbers
? Neoprene
? Leak-lock
? Permatex
? Ordinary oil and grease
? Nordel 1145 RPT elastomer, unfilled and
Si02-filled
? silicon elastomer, unfilled and SiOrfilled
? CIS-4 polybutadiene elastomer, unfilled
and SiOrfilled
Safety Profile
Poison by inhalation.
An irritant to skin, eyes, and mucous
membranes comparable to chlorine,
fluorine, arsine, and phosgene. The liquid
causes local inflammation, blisters, redness,
and swelling. Injuries to central nervous
system, liver, and hdneys have also been
produced in experimental animals. Sirmlar
observations have been reported in humans,
resulting at times in a reaction resembling
metal fume fever. Human exposure to
pentaborane has produced signs of severe
central nervous system irritation such as
drowsiness, dlzziness, visual disturbances,
muscle twitching, and in severe cases,
painful muscle spasm. Dangerously
flammable when exposed to heat or flame
or by chemical reaction. On contact with
moisture, hydrogen is usually evolved.
Highly explosive when exposed to heat or
flame. Explosive reaction with air,
tetravinyllead, O2 above 165℃, octanol
oxime + sodium hydroxide, benzene vapor,
HNO3Cl2. Violent reaction with halocarbon
liquids. Other boron hydrides evolve H2
upon contact with moisture or can
propagate a flame rapidly enough to cause
an explosion. Heat can cause these materials
to decompose violently or at least to evolve
H2. They also react with water or steam to
evolve hydrogen. Reaction with Al or Li
forms complex hydrides that may ignite
spontaneously in air. Powerful oxidlzing
agents, such as chlorine gas, etc., can react
violently with boron hydrides. Pentaborane
(stable) is spontaneously flammable in air.
See also BORANES and HYDRIDES.
Potential Exposure
Diborane is used as the source of
boron in the semiconductor industry; as a catalyst for olefin
polymerization; a rubber vulcanizer; a reducing agent;
a flame-speed accelerator; a chemical intermediate for
other boron hydrides; as a doping agent; in rocket propel-
lants, and in the conversion of olefins to trialkyl boranes
and primary alcohols.
Physiological effects
ACGIH recommends a Threshold Limit Value-Time-
Weighted Average (TLV-TWA) of 0.1
ppm (0.11 mg/m3
) for diborane. The TLVTWA
is the time-weighted average concentration
for a normal 8-hour workday and a 40-hour
workweek, to which nearly all workers may be
repeatedly exposed, day after day, without adverse
effect.
OSHA lists an 8-hour Time-Weighted Average-
Permissible Exposure Limit (TWA-PEL)
of 0.1 ppm (0.1 mg/m3
) for diborane. TWAPEL
is the exposure limit that shall not be exceeded
by the 8-hour time-weighted average in
any 8-hour work shift of a 40-hour workweek
storage
diborane should be used only in a fume hood free of ignition sources and should be stored in a cold, dry, wellventilated area separated from incompatible substances and isolated from sources of sparks and open flames.
Shipping
UN1911 Diborane, Hazard Class: 2.3; Labels:
2.3-Poisonous gas, 2.1-Flammable gas Inhalation Hazard
Zone A. Cylinders must be transported in a secure upright
position, in a well-ventilated truck. Protect cylinder and
labels from physical damage. The owner of the compressed
gas cylinder is the only entity allowed by federal law
(49CFR) to transport and refill them. It is a violation of
transportation regulations to refill compressed gas cylinders
without the express written permission of the owner.
Incompatibilities
A strong reducing agent. Unstable above
8
C. The presence of contaminants may lower the autoigni-
tion temperature; ignition may take place at, or below,
room temperature. Diborane can polymerize, forming liquid
pentaborane (See P:0190). It ignites spontaneously in moist
air; and on contact with water, hydrolyzes exothermically
forming hydrogen and boric acid. Contact with halogenated
compounds (including fire extinguishers) may cause fire
and explosion. Contact with aluminum, lithium and other
active metals form hydrides which may ignite spontane-
ously. Incompatible with aluminum, carbon tetrachloride;
nitric acid; nitrogen trifluoride and many other chemicals.
Reacts with oxidized surfaces. Attacks some plastics,
rubber or coatings.
Waste Disposal
Return refillable compressed
gas cylinders to supplier. Incineration with aqueous scrub-
bing of exhaust gases to remove B2O3 particulates.
GRADES AVAILABLE
Diborane is sold in ambient or refrigerated cylinders
with a purity of 99 percent or greater. It
is commonly used in the electronics industry,
mainly in the form of dilute mixtures.
Check Digit Verification of cas no
The CAS Registry Mumber 19287-45-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,2,8 and 7 respectively; the second part has 2 digits, 4 and 5 respectively.
Calculate Digit Verification of CAS Registry Number 19287-45:
(7*1)+(6*9)+(5*2)+(4*8)+(3*7)+(2*4)+(1*5)=137
137 % 10 = 7
So 19287-45-7 is a valid CAS Registry Number.
InChI:InChI=1/B2H6/c1-3-2-4-1/h1-2H2
19287-45-7Relevant articles and documents
Elucidation of the Formation Mechanisms of the Octahydrotriborate Anion (B3H8-) through the Nucleophilicity of the B-H Bond
Chen, Xi-Meng,Ma, Nana,Zhang, Qian-Fan,Wang, Jin,Feng, Xiaoge,Wei, Changgeng,Wang, Lai-Sheng,Zhang, Jie,Chen, Xuenian
, p. 6718 - 6726 (2018)
Boron compounds are well-known electrophiles. Much less known are their nucleophilic properties. By recognition of the nucleophilicity of the B-H bond, the formation mechanism of octahydrotriborate (B3H8-) was elucidated on the bases of both experimental and computational investigations. Two possible routes from the reaction of BH4- and THF·BH3 to B3H8- were proposed, both involving the B2H6 and BH4- intermediates. The two pathways consist of a set of complicated intermediates, which can convert to each other reversibly at room temperature and can be represented by a reaction circle. Only under reflux can the B2H6 and BH4- intermediates be converted to B2H5- and BH3(H2) via a high energy barrier, from which H2 elimination occurs to yield the B3H8- final product. The formation of B2H6 from THF·BH3 by nucleophilic substitution of the B-H bond was captured and identified, and the reaction of B2H6 with BH4- to produce B3H8- was confirmed experimentally. On the bases of the formation mechanisms of B3H8-, we have developed a facile synthetic method for MB3H8 (M = Li and Na) in high yields by directly reacting the corresponding MBH4 salts with THF·BH3. In the new synthetic method for MB3H8, no electron carriers are needed, allowing convenient preparation of MB3H8 in large scales and paving the way for their wide applications.
Gas-phase inorganic chemistry: Laser spectroscopy of calcium and strontium monoborohydrides
Pianalto,Bopegedera,Fernando,Hailey,O'Brien,Brazier,Keller,Bernath
, p. 7900 - 7903 (1990)
The CaBH4 and SrBH4 free radicals were synthesized by the reaction of Ca or Sr vapor with diborane, B2H6. The ?2A1-X?xA1 and B?2E-X?2A1 electroni
Boron-carbon nanotubes from the pyrolysis of C 2 H 2 -B 2 H 6 mixtures
Satishkumar,Govindaraj,Harikumar,Zhang, Jin-Ping,Cheetham,Rao
, p. 473 - 477 (1999)
Boron-doped carbon nanotubes have been prepared by the pyrolysis of acetylene-diborane mixtures in a stream of helium and hydrogen. The nanotubes so obtained have compositions around C35B. The presence of boron favours nanotube formation and the boron content does not vary with the depth. Considering that the nitrogen-doped nanotubes, reported recently (Chem. Phys. Lett. 287 (1997) 671) have the average composition C35N, it may be possible to use a combination of these p-type and n-type nanotubes for certain applications.
Infrared spectrum of the novel electron-deficient BH4 radical in solid neon
Andrews, Lester,Wang, Xuefeng
, p. 7280 - 7281 (2002)
Laser-ablated boron reacts with hydrogen on condensation in excess neon to give BH4 radical, BH4- anion, and B2H6 as the major products. Identifications are based on 10B and D substitution,
Synthesis and characterization of the homoleptic octahydrotriborate complex Cr(B3H8)2 and its Lewis base adducts
Goedde, Dean M.,Windler, G. Kenneth,Girolami, Gregory S.
, p. 2814 - 2823 (2007)
Solvate-free sodium octahydrotriborate, NaB3H8, is prepared on a 20 gram scale from sodium amalgam and diborane in diethyl ether. This substance, which is chemically related to borohydride-based compounds being investigated as hydrogen storage materials, is also useful for the preparation of transition-metal complexes bearing B3H8 ligands. Treatment of CrCl3 with NaB3H8 affords a thermally unstable purple liquid thought to be a chromium(III) hydride of stoichiometry CrH(B3H8)2. This hydride converts rapidly at room temperature to the chromium(II) complex Cr-(B3H 8)2, which adopts a square-planar structure in which four hydrogen atoms form the coordination sphere of the chromium atom. This chromium(II) species forms six-coordinate Lewis base adducts Cr(B 3H8)2L2, where L is Et2O, THF, or PMe3; the first two of these adopt trans geometries, whereas the latter is cis. Volatile Cr(B3H8)2 is the first homoleptic transition-metal complex of the octahydrotriborate anion, and it is an excellent single-source precursor for the chemical vapor deposition of thin films of CrB2 at temperatures as low as 200°C. Crystal structures of the new complexes are reported.
Reactions of tetraalkylammonium octahydrotriborates with aluminum tetrahydroborate
Titov,Zhemchugova
, p. 724 - 725 (1998)
The reactions of R4NB3H8 (R = Me, Et, or Bu) with Al(BH4)3 at 20°C afforded R4N[Al(BH4]4] and were accompanied by liberation of tetraborane(10) as the major product. T
Synthesis of Bu4NB11H14 by the reaction of tetrabutylammonium octahydrotriborate with diborane in diglyme
Gavrilova,Titov,Petrovskii
, p. 307 - 308 (2004)
The method for synthesis of Bu4NB11H14 by dehydrocondensation of Bu4NB3H8 with diborane in diglyme in the temperature range of 70-90°C was developed. The product is formed in 75-85% yield.
Kinetics and Mechanism of the Thermal Decomposition of Hexaborane (12) in the Gas Phase
Greatrex, Robert,Greenwood, Norman N.,Waterworth, Simon D.
, p. 925 - 926 (1988)
The gas-phase thermolysis of arachno-B6H12 produces predominantly B5H9 and B2H6 in a molar ratio of 2:1 via a first-order reaction having Arrhenius parameters which are essentially identical to those reported for the decomposition of the structurally related B5H11; these results imply a mechanism involving elimination of BH3 as the rate-determining initial step in both reactions.
Photoelectron spectroscopy of BH3-
Wickham-Jones, C. Tom,Moran, Sean,Ellison, G. Barney
, p. 795 - 806 (1989)
We have studied the photoelectron spectra of BH3- and BD3- and have measured the electron affinities of borane; we find EA(BH3)=0.038+/-0.015 eV and EA(BD3)=0.027+/-0.014 eV.The peak splittings and intensities demonstrate that the BH3- ion and the BH3 neutral have very similar geometries; our spectra are consistent with a planar structure for both species.Variational calculations of a coupled oscillator basis over an ab initio potential give an excellent fit to the experimental frequencies and photodetachment Franck-Condon factors.This ab initio model leads toequilibrium geometries with both BH3 and BH3- as planar molecules with re(BH3-)=1.207 Angstroem and re(BH3)=1.188 Angstroem.We find ΔHf0 o(BH3-)=23.1+/-3.8 kcal mol-1.
Arachno-2-Gallatetraborane(10), H2GaB3H8: Synthesis, Properties and Structure of the Gaseous Molecule as determined by Electron Diffraction
Pulham, Colin R.,Downs, Anthony J.,Rankin, David W. H.,Robertson, Heather E.
, p. 1520 - 1521 (1990)
The novel hydride arachno-2-gallatetraborane(10), H2GaB3H8, synthesised by metathesis involving monochlorogallane and tetra-n-butylammonium octahydridotriborate, is characterised by its spectroscopic and chemical properties; electron diffraction confirms
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