19624-22-7 Usage
Description
Pentaborane is a nonmetallic, colorless liquid with a pungent odor. It decomposes at 300°F (148°C), if it has not already ignited, and will ignite spontaneously in air if impure. It is a dangerous fire and explosion risk, with a flammable range of 0.46%–98% in air. Boiling point is 145°F (64°C), flash point is 86°F (30°C), and ignition temperature is 95°F (35°C), which is extremely low. Any object that is 95°F (35°C) or above can be an ignition source. Ignition sources can be ordinary objects on a hot day in the summer, such as the pavement, metal on vehicles, and even the air. In addition to extreme flammability, it is also toxic by ingestion or inhalation and is a strong irritant. TLV is 0.005 ppm in air, and it is immiscible in water. The four-digit UN identification number is 1380. The NFPA 704 designation for pentaborane is health 4, flammability 4, and reactivity 2. The primary uses are as fuel for air-breathing engines and as a propellant.
Chemical Properties
Pentaborane is a colorless, volatile liquid.
Unpleasant, sweetish odor, like sour milk. The Odor
Threshold is 0.8 ppm.
Uses
Different sources of media describe the Uses of 19624-22-7 differently. You can refer to the following data:
1. There appears to be no commercial market for pentaborane.
In the 1950s it was explored as a potential rocket fuel.
2. Reducing agent in propellant fuels
General Description
A clear colorless liquid with a pungent odor like sour milk, and flammable.It is corrosive to natural rubber, some synthetic rubber, some greases, and some lubricants and gives off irritating or toxic fumes (or gases) in a fire. It reacts violently with fire. Pentaboron nonahydride incompatible with strong oxidants such as chromium anhydride, chlorate and potassium permanganate, and other contacts. Vapors toxic both under prolonged exposure to low concentrations and short exposure to high concentrations. Density 0.61 g / cm3. Under prolonged exposure to intense heat the containers may rupture violently and rocket.
Air & Water Reactions
Highly flammable. May ignite spontaneously in air [Merck 11th ed. 1989]. Slowly decomposes in water.
Reactivity Profile
Pentaborane is an extremely reactive reducing agent. Can ignite spontaneously in contact with air and many other materials. Reactions with oxygen are often violently explosive. Reacts with ammonia to form a diammoniate. Is stabilized by the formation of complexes with N, O, P, or S. Is stable in hydrocarbon solvents, but forms shock sensitive solutions in most carbonyl containing solvents.
Health Hazard
May cause death or permanent injury after very short exposure to small quantities.
Fire Hazard
Ignites spontaneously in air. Reacts violently with halogenated extinguishing agents. Boron hydrides present considerable fire and explosion hazard. They undergo explosive reaction with most oxidizing agents, including halogenated hydrocarbons. Fires tend to reignite. On decomposition, Pentaborane emits toxic fumes and can react vigorously with oxidizing materials. Avoid dimethyl sulfoxide, water, most oxidizing agents (including halogenated hydrocarbons). Avoid direct sunlight and sources of ignition, decomposes very slowly at 302. Hazardous polymerization may not occur.
Safety Profile
Poison by inhalation and intraperitoneal routes. Dangerous fire hazard by chemical reaction; spontaneously flammable in air. Dangerous explosion hazard. To fight fire, use special fire-fighting materials; water is not effective; reacts violently with halogenated extinguishing agents. Get instructions from supplier. Explosive reaction with oxygen. Forms shock-sensitive solutions in solvents containing carbonyl, ether, or ester functions; or halogens. Incompatible with dimethyl sulfoxide. Upon decomposition it emits toxic fumes of B. See also BORANES and BORON COMPOUNDS
Potential Exposure
Pentaborane is used in rocket propellants
and in gasoline additives.
Shipping
UN1380 Pentaborane, Hazard Class: 4.2; Labels:
4.2-Spontaneously combustible material, 6.1-Poisonous
materials. Inhalation Hazard Zone A.
Incompatibilities
Pentaborane is an extremely reactive
reducing agent. It can ignite spontaneously in contact with
air and many other materials. Reactions with oxygen are
often violently explosive. Reacts with ammonia to form
a diammoniate. Reacts on contact with water, oxidizers,
halogens, including halogenated hydrocarbons. May sel-heat
and ignite spontaneously in moist air, decomposes @ 150C.
Hydrolyzes slowly with heat in water to form boric acid.
Contact with solvents, such as ketones, ethers and esters form
shock-sensitive compounds. Pentaborane is stable in hydrocarbon
solvents, but forms shock sensitive solutions in most
carbonyl containing solvents. Corrosive to natural rubber,
some synthetic rubbers and to some lubricants. Avoid
dimethyl sulfoxide, direct sunlight and sources of ignition.
Check Digit Verification of cas no
The CAS Registry Mumber 19624-22-7 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,9,6,2 and 4 respectively; the second part has 2 digits, 2 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 19624-22:
(7*1)+(6*9)+(5*6)+(4*2)+(3*4)+(2*2)+(1*2)=117
117 % 10 = 7
So 19624-22-7 is a valid CAS Registry Number.
InChI:InChI=1/B5H9/c6-2-1-3(2,6)5(1,8-3)4(1,2,7-2)9-5/h1-5H
19624-22-7Relevant articles and documents
Greenwood, Norman N.,Kennedy, John D.,Staves, John
, (1978)
Greenwood, Norman N.,Staves, John
, (1977)
Chemical and phase transformations in the systems hydrogen-sorbing intermetallic compound-diborane
Kravchenko,Kalinnikov,Shilkin
, p. 865 - 867 (2007/10/03)
The reactions of the intermetallic compounds CeFe2, CeCo 2, and λ3-ScFe2 with B2H 6 at 4.8 × 103 Pa, 293-573 K, and various contact times were studied. CeFe2 decompose
Kinetic studies of reactions of hexaborane(10) with other binary boranes in the gas phase
Attwood, Martin D.,Greatrex, Robert,Greenwood, Norman N.,Potter, Christopher D.
, p. 144 - 152 (2007/10/03)
Cothermolysis reactions of B6H10 with the binary boranes B2H6, B4H10, B5H9, and B5H11 have been studied by a quantitative mass-spectrometric technique to gain insight into the role of B6H10 in borane interconversion reactions. Except in the B6H10-B5H9 system the initial rate of consumption of B6H10 was found to be considerably more rapid than in the thermolysis of B6H10 alone, indicating that interactions were occuring. Detailed kinetic studies of the B6H10-B2H6 and B6H10-B4H10 reactions showed that the rate of consumption of B6H10 was governed in each case by the rate-determining step in the decomposition of the co-reactant, the orders being 3/2 with respect to B2H6 and 1 with respect to B4H10; a considerable increase in the conversion of B6H10 to B10H14 at the expense of polymeric solids was also observed. Added hydrogen was found to have very little effect on the reaction rates and product distributions in the cothermolysis reactions, in marked contrast to its effect on the reactions of B2H6 and B4H10 alone. The kinetic results are entirely consistent with earlier suggestion, based on qualitative observations, that the reactive intermediates {B3H7} and {B4H8} are scavenged by reactions with B6H10, and suggest strongly that this borane, unlike B6H12, plays a pivotal role in the build-up to B10H14 and other higher boranes.
