7789-59-5 Usage
Description
Phosphorus oxybromide, also known as phosphorus pentabromide, is a colorless to grey-brown crystalline solid or fused mass with a pungent odor. It is commonly heated and shipped in a molten state. Phosphorus oxybromide is soluble in water but decomposes upon contact, producing hydrobromic and phosphoric acid along with the release of heat. It is highly reactive with organic materials, causing fire, and can evolve toxic and corrosive gases when exposed to fire. It is corrosive to metals and tissue and is used in the production of various chemicals.
Uses
1. Chemical Synthesis:
Phosphorus oxybromide is used as a reagent in the preparation of phosphoryl halides for N-protection of amino acids using group-assisted purification (GAP). It is also employed as a brominating agent in the synthesis of various compounds, such as 2,4,6-tribromopyrimidine and bromoheterocyclic compounds.
2. Flame Retardant Production:
In the chemical process, phosphorus oxybromide can be used as an intermediate and serves as a raw material for manufacturing bromine flame retardants.
3. Bromination of Organic Compounds:
Phosphorus oxybromide is utilized as a brominating reagent in the synthesis of various organic compounds, contributing to its versatility in chemical applications.
4. Manufacturing Other Chemicals:
As a versatile reagent, phosphorus oxybromide is used in the production of other chemicals, highlighting its importance in the chemical industry.
Chemical Properties:
Phosphorus oxybromide appears as colorless or pale orange crystals with an irritating odor. It has a relative density of 2.822, a melting temperature of 56 °C, a boiling point of 191.7 ℃, and an evaporation heat of 38 Kj/mol. It is soluble in ether, benzene, chloroform, carbon disulfide, and concentrated sulfuric acid. It can be slowly hydrolyzed to phosphoric acid and HBr in water.
Category:
Phosphorus oxybromide is classified as a corrosive item due to its reactivity with organic materials, metals, and tissue, as well as its ability to produce toxic and corrosive gases when exposed to fire.
Toxicity
It has similar toxicity to the phosphorus oxychloride. It can react with water, emitting a white smoke-like, irritant and corrosive hydrogen bromide gas which has strong irritation to the eyes, mucous membranes and skin. The patients having inhaled of the vapor or smoke should be sent away from the contaminated area for rest and keeping warm. If eyes are irritated, rinse with water. Upon severe cases, send for medical treatment. Upon skin contact, first rinse with water, and then thoroughly wash with soap. If burned, go for medical treatment. Upon mistakenly administration, immediately gargle and immediately go to the hospital for treatment.
Preparation
Phosphorus oxychloride method: take phosphorus oxychloride as raw material and aluminum trichloride as the catalyst, upon heating at about 80 ℃, introduce hydrogen bromide gas for reaction, generating tribromo phosphorus. The reaction is:
POC13 + 3HBr → POBr3 + 3HCl ↑
The produced hydrogen chloride gas during the reaction, after being absorbed by water, can produce dilute hydrochloric acid.
Phosphorus tribromide method: to a round bottom flask equipped with a reflow condenser, add the mixture of phosphorus pentabromide and phosphorus pentoxide (250 g of PBr5/about 30 g of P2O5) and heat slowly to 150 ° C. Phosphorus pentoxide is a bit more than the phosphorus pentabromide in stoichiometry. At this time, one the one hand, pay attention to expel the bromine out; on the other hand, make sure that the reaction is completed within 5h.
Then, 10 g of bromine and equivalent amount of phosphorus pentoxide were added to the melt and refluxed at 150 ° C for several hours. This is because it takes time for the intermediate product, phosphorus tribromide, to be oxidized to phosphorus pentabromide and transited to tribromonic phosphorus. The resultant was subjected to vacuum distillation under reduced pressure. After removing the initial distillate and the phosphorus tribromide contained therein, the trapping was carried out. The receiver is cooled with ice brine to generate tribromo phosphorus. Its reaction is:
3PBr5 + P2O5 → 5POBr3
Flammability and Hazardous characteristics
It is subject to decomposition upon coming across water, generating toxic hydrogen bromide gas.
Storage characteristics warehouse
ventilated, low temperature and dry; it should be stored separately from combustible product.
Fire extinguishing agent
Dry powder
Reactivity Profile
Phosphorus oxybromide is incompatible with water, strong oxidizing agents, alcohols, bases, including amines. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291].
Health Hazard
CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Fire will produce irritating, corrosive and/or toxic gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause pollution.
Fire Hazard
EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may burn, but none ignite readily. May ignite combustibles (wood, paper, oil, clothing, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff. Flammable/toxic gases may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. Substance may be transported in a molten form.
Safety Profile
Poison by ingestion,
inhalation, and shin contact. A corrosive
irritant to skin, eyes, and mucous
membranes. A corrosive material. Reacts
with steam, water to produce much heat
with toxic fumes. When heated to decomposition it emits very toxic fumes of
Brand POx. See also BROMIDES.
Check Digit Verification of cas no
The CAS Registry Mumber 7789-59-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,7,8 and 9 respectively; the second part has 2 digits, 5 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 7789-59:
(6*7)+(5*7)+(4*8)+(3*9)+(2*5)+(1*9)=155
155 % 10 = 5
So 7789-59-5 is a valid CAS Registry Number.
InChI:InChI=1/Br3OP/c1-5(2,3)4
7789-59-5Relevant articles and documents
Greenwood, N. N.,Worrall, I. J.
, p. 34 - 41 (1958)
The gas-phase on-line production of phosphoryl halides, POX3 and their identification by infrared spectroscopy
Allaf, Abdul W.
, p. 921 - 926 (2007/10/03)
A new route has been devised, leading to the production of POX3 molecules where X = F, Br and I by an on-line process using phosphoryl chloride, POCl3 as a starting material passed over heated sodium fluoride, NaF, potassium bromide, KBr and potassium iodide, KI at 535, 690 and 480°C, respectively. The products have been characterised by the infrared (IR) spectra of their vapours. The low resolution gas-phase Fourier transform infrared spectra reported for the first time show strong bands centered at 1416.6, 1312.9, 1297.9 and 1285 cm-1, assigned to ν1(a1), the O=P stretching fundamental of POF3, POCl3, POBr3 and POI3, respectively.
MASS SPECTROMETRIC AND MATRIX INFRARED INVESTIGATIONS OF THE FORMATION OF GASEOUS POBr.
Binnewies,Lakenbrink,Schnoeckel
, p. 83 - 94 (2008/10/08)
By reaction of mixtures of PBr//3 and O//2 with silver at about 1100 K, gaseous POBr is formed; this has been shown by mass spectrometric and infrared matrix measurements. The calculated values for the heat of formation and entropy are: DELTA H degree //2//9//8 (POBr) equals 10. 8 kJ/mol, S degree //2//9//8 (POBr) equals 292. 9 J/K multiplied by (times) mol. Based on the following three vibrational frequencies (1253. 0, 407. 1, and 253. 7 cm** minus **1) and some isotropic shifts (**1**60/**1**8O), approximate force constants have been calculated.