7758-02-3

Basic information

• Product Name: Potassium bromide
• Synonyms: Potassiumbromide (8CI);NSC 77367
• CAS NO: 7758-02-3
• Molecular Formula: BrK
• Molecular Weight: 119.0023
• EINECS: 231-830-3
• Mol File: 7758-02-3.mol

Chemical Properties

• Melting Point: 734℃
• Boiling Point: 58.8 °C(lit.)
• Flash Point: 1435 °C
• Appearance: odourless white or colourless crystalline solid
• Density: 3.119 g/mL at 25 °C(lit.)
• Vapor Density: 7.14 (vs air)
• Vapor Pressure: 175 mm Hg ( 20 °C)
• Refractive Index: 1.559
• Storage Temp.: Store at +5°C to +30°C.
• Solubility: H2O: 1?M at?20?°C, clear, colorless
• Water Solubility: 650 g/L (20℃)
• Stability: Stable. Incompatible with strong oxidizing agents, strong acids, bromine trifluoride and bromine trichloride.
• Merck: 14,7618
• CAS DataBase Reference: Potassium bromide(CAS DataBase Reference)
• NIST Chemistry Reference: Potassium bromide(7758-02-3)
• EPA Substance Registry System: Potassium bromide(7758-02-3)

Safety Data

• Hazard Codes: Xi:Irritant
• Statements: R36:
• Safety Statements: S26:; S39:
• RIDADR: UN 1744 8/PG 1
• WGK Germany: 2
• RTECS: TS7650000
• F: 3-10
• TSCA: Yes
• Hazardous Substances Data: 7758-02-3(Hazardous Substances Data)

Usage

Chemical Description

Potassium bromide is a white crystalline powder used as a spectroscopic standard.

Uses

Used in Photographic Industry:
Potassium bromide was used as a secondary halide in combination with an iodide in the paper negative processes, the albumen on glass process, and the wet collodion processes. When silver bromide gelatin emulsion was invented, potassium bromide became the primary halide. It was also used in combination with either bichloride of mercury, copper sulfate, or potassium ferricyanide in photographic bleaches and as a restrainer in alkaline developers used for gelatin plates and developing-out papers.
Used in Infrared Spectroscopy:
Because of its range of transparency to infrared radiation, KBr is used both as a matrix for solid samples and as a prism material in infrared spectroscopy. Potassium bromide is widely used in optics due to its low refractive index and wide spectral range into the infrared with nearly no absorption. As a result, KBr is widely used as infrared optical windows, as infrared beamsplitters, and as substrates for interferometers. Commonly, KBr is used in transmission infrared spectroscopy as a media for powder samples.
Used in Synthesis:
Potassium bromide has been used in synthesis, commonly as a source of bromide ions. For example, double displacement of KBr and bismuth nitrate yielded nanosheets of bismuth oxybromide. Solutions of KBr have also been found to be useful shape-control agents or crystal-habit modifiers in the formation of metal nanocrystals, including palladium nanorods and bimetallic platinum-palladium nanocrystals. KBr is a common source of bromide ions used as nucleophiles in organic chemistry.
Used as a Sedative:
Potassium bromide is also used as a sedative due to its calming effects.

Preparation

Potassium bromide was produced by the action of bromine on hot potassium hydroxide solution or Reacting elemental bromine with potassium hydroxide or potassium iodide will produce the potassium bromide salt:KOH + Br2 → KBr + HOBrKI + Br2 → KBr + I2The reaction of bromine with potassium carbonate and urea is the basis of the process. The first step of the process involves the addition of K2SO4 to the potassium carbonate solution, followed by heating to 80 °C. After the lead-containing precipitate is removed by filtration, the bromine and urea are added, and the temperature and pH are adjusted to 30 °C and 6.0-6.5, respectively. Potassium bromide is recovered by recrystallization after reduction of volume of the reacting solution by evaporation. The sulfate can be removed from the solution by addition of BaBr2.

Reactivity Profile

Potassium bromide is not in generally strongly reactive. A weak reducing agent, incompatible with oxidizing agents. Also incompatible with salts of mercury and silver. Violent reactions occur with bromine trifluoride. May react with nitrous ether spirit, many alkaloidal salts and starch. May also react with acids . Reacts with concentrated sulfuric acid to generate fumes of hydrogen bromide.

Hazard

Toxic by ingestion and inhalation

Fire Hazard

Flash point data for Potassium bromide are not available; however, Potassium bromide is probably nonflammable.

Flammability and Explosibility

Nonflammable

Biochem/physiol Actions

Potassium bromide (KBr) is used as an anticonvulsant and sedative. KBr is used for optical windows and prisms. KBr is transparent in the wide wavelength range from near ultraviolet to long wave infrared. It is employed in the sample preparation for infrared transmission spectra.

Safety Profile

Moderately toxic by ingestion and intraperitoneal routes. Large doses can cause central nervous system depression. Prolonged inhalation may cause skin eruptions. Mutation data reported. Violent reaction with BrF3. When heated to decomposition it emits toxic fumes of K2O and Br-. See also BROMIDES.

Veterinary Drugs and Treatments

Bromides are used both as primary therapy and as adjunctive therapy to control seizures in dogs that are not adequately controlled by phenobarbital (or primidone) alone (when steady state trough phenobarbital levels are >30 mcg/mL for at least one month). While historically bromides were only recommended for use alone in patients suffering from phenobarbital (or primidone) hepatotoxicity, they are more frequently used as a drug of first choice. Although not frequently used, bromides are also considered suitable by some for use in cats with chronic seizure disorders, but cats may be more susceptible to the drug’s adverse effects.

Purification Methods

Crystallise the bromide from distilled water (1mL/g) between 100o and 0o. Wash it with 95% EtOH, followed by Et2O. Dry it in air, then heat it at 115o for 1hour, pulverize it, then heat it in a vacuum oven at 130o for 4hours. It has also been crystallised from aqueous30% EtOH, or EtOH, and dried over P2O5 under vacuum before heating in an oven.

InChI:InChI=1/BrH.K/h1H;/q;+1/p-1

Upstream product

• 7726-95-6 bromine 
• 584-08-7 potassium carbonate 
• 21109-95-5 barium sulfide 
• 10035-10-6 hydrogen bromide 
• 7789-41-5 calcium bromide 
• 302-04-5 Thiocyanate 
• 7440-09-7 potassium 
• 7758-09-0 potassium nitrite 
• 590-29-4 potassium formate 
• 7789-23-3 potassium fluoride 
• 7550-35-8 lithium bromide 
• 7758-01-2 potassium bromate 
• 1643-19-2 tetrabutylammomium bromide 
• 14866-33-2 tetraoctyl ammonium bromide 

Downstream Products

• 7787-69-1 caesium bromide 
• 7789-23-3 potassium fluoride 
• 7789-46-0 iron(II) bromide 
• 183388-29-6 HPdBr(PPh₃)2 
• 32993-06-9 [(η5-cyclopentadienyl)Ru(PPh3)2Br] 
• 33409-76-6 (C₆H₅C₆H₅)2Cr⁽¹⁺⁾*Br^(1-)=(C₆H₅C₆H₅)2CrBr 
• 108-95-2 phenol 
• 15162-90-0 nitrogen tribromide 
• 15656-19-6 hypobromous acid 
• 21308-68-9 cis-dibromobis(benzonitrile)platinum(II) 

Relevant articles and documents

A novel zero valent metal bismuth for bromate removal: Direct and ultraviolet enhanced reduction

Bromate (BrO3-) is a carcinogenic and genotoxic by-product of the ozone disinfection process. In this study, a new zero-valent metal, bismuth, was used to reduce bromate. Bismuth samples were prepared by a solvothermal method and characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The morphology of the bismuth powder was microspheres assembled with dense nanosheets. The kinetics of the direct bromate reduction by bismuth accorded with the pseudo-first-order kinetics model. The rate coefficients of the initial bromate concentration of 1.00 mg L-1, 2.50 mg L-1, 5.00 mg L-1 were identically close to 0.08 min-1. For 0.20 mg L-1, a reaction rate coefficient near 0.10 min-1 was obtained. The reducing products of bromate included bromide ions (Br-) and bismuth oxybromides. The bromate removal efficiency was enhanced remarkably in the presence of ultraviolet (UV) light, and the corresponding kinetic coefficient was 4 times higher than that of direct reduction. The mechanism of ultraviolet enhancement was analyzed by diffuse reflectance spectroscopy (DRS), the density functional theory (DFT) calculation, open circuit potential (OCP) analysis, photocurrent measurement and linear sweep voltammetry (LSV). Besides, the influence of dissolved oxygen (DO) on bromate reduction efficiency and the sustainability of the as-prepared sample were investigated. DO inhibited the reduction rate obviously, but showed a slight effect on the formation of bromide ions. In the long-term periodic experiments, the kinetic coefficient decay occurred in both direct (without UV irradiation) and ultraviolet assisted bromate reduction. However, the kinetic coefficient of UV-assisted reduction (0.115 min-1) was about 2 times higher than that of the direct reduction in the last cycle of periodic experiments. In conclusion, the novel bromate reduction strategy based on the zero-valent bismuth metal material has been proved efficient and sustainable, which contributes to the development of drinking water treatment technologies.

Ion Exchange of Layered Alkali Titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with Alkali Halides by the Solid-State Reactions at Room Temperature

Ion exchange of layered alkali titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with several alkali metal halides surprisingly proceeded in the solid-state at room temperature. The reaction was governed by thermodynamic parameters and was completed within a shorter time when the titanates with a smaller particle size were employed. On the other hand, the required time for the ion exchange was shorter in the cases of Cs2Ti5O11 than those of K2Ti4O9 irrespective of the particle size of the titanates, suggesting faster diffusion of the interlayer cation in the titanate with lower layer charge density.

Eu(O2C-C≡C-CO2): An EuII Containing Anhydrous Coordination Polymer with High Stability and Negative Thermal Expansion

Anhydrous EuII–acetylenedicarboxylate (EuADC; ADC2? = ?O2C-C≡C-CO2 ?) was synthesized by reaction of EuBr2 with K2ADC or H2ADC in degassed water under oxygen-free conditions. EuADC crystallizes in the SrADC type structure (I41/amd, Z=4) forming a 3D coordination polymer with a diamond-like arrangement of Eu2+ nodes (msw topology including the connecting ADC2? linkers). Deep orange coloured EuADC is stable in air and starts decomposing upon heating in an argon atmosphere only at 440 °C. Measurements of the magnetic susceptibilities (μeff=7.76 μB) and 151Eu M?ssbauer spectra (δ=?13.25 mm s?1 at 78 K) confirm the existence of Eu2+ cations. Diffuse reflectance spectra indicate a direct optical band gap of Eg=2.64 eV (470 nm), which is in accordance with the orange colour of the material. Surprisingly, EuADC does not show any photoluminescence under irradiation with UV light of different wavelengths. Similar to SrADC, EuADC exhibits a negative thermal volume expansion below room temperature with a volume expansion coefficient αV=?9.4(12)×10?6 K?1.

Enhanced liquid phase catalytic hydrogenation reduction of bromate over Pd-on-Au bimetallic catalysts

Pd-Au/TiO2 bimetallic catalysts with varied Au contents were prepared by the sequential photocatalytic deposition method and the liquid phase catalytic hydrogenation reduction of bromate over these catalysts was investigated. The catalysts were characterized using X-ray diffraction, transmission electron microscope, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, H2 chemisorption and energy dispersive spectroscopy. Characterization results showed that Pd atoms were site-deposited on the surface of varied size Au cores and formed Pd-on-Au core-shell like bimetallic nanoparticles on TiO2. The bimetallic catalysts showed higher Pd dispersions and more exposed active sites than that of Pd/TiO2, and the amount of exposed active sites first increased then decreased with Au content. For a similar Pd loading, the bimetallic catalyst exhibited volcano-shape activity as a function of Au loading and the highest activity was identified on Pd-Au(1.0)/TiO2 with Au core size around 8.4 nm. In addition, the catalytic reduction of bromate could be well-fitted by the Langmuir-Hinshelwood model, reflecting an adsorption controlled mechanism.

Synthesis, characterization, and catalytic behavior of methoxy- and dimethoxy-substituted pyridinium-type ionic liquids

Synthesis of methoxy-substituted pyridinium-type ionic liquids from a nontoxic and easy method is described. Catalytic behaviors of synthesized ionic liquids were investigated with various concentrations for the Mannich reaction. We have observed that methoxy- and dimethoxy-substituted pyridinium bromides showed better catalytic behavior than other ionic liquids.

Complex antimony(III) oxohalides: Synthesis and physicochemical properties

Complexes of the formula MSb2BrF4O (M = K, Rb, and NH4) were obtained from aqueous solutions of SbF3 and MBr and examined by chemical analysis, X-ray diffraction, thermal analysis, and IR, Raman, and 19F NMR spectroscopy. It was found that the red reflectance is 74-97% and the UV reflectance is 7-15%. The highest averaged reflectance (93%) was observed for KSb2BrF4O. The decomposition temperatures of MSb2BrF4O (M = K, Rb, and NH4) are 230, 197, and 223°C, respectively. Pleiades Publishing, Ltd., 2012.

Effect of precompression on isothermal decomposition kinetics of pure and doped potassium bromate

Pure and doped samples of potassium bromate (KBrO3) were subjected to precompression and their thermal decomposition kinetics was studied by thermogravimetry at 668 K. The samples decomposed in two stages governed by the same rate law (contracting square equation), but with different rate constants, k 1 (for a α ≤ 0.45) and k 2 (for α ≥ 0.45), as in the case of uncompressed samples. The rate constants k 1 and k 2 decreased dramatically on precompression, the decrease being higher for doped samples.Cation dopants (Ba2+, Al3+) caused more desensiti zation effect than the anion dopants (SO42-, PO4 3-) of the same magnitude of charge and concentration. The results favor ionic diffusion mechanism proposed earlier on the basis of doping studies.

Synthesis and characterization of K8-x(H2) ySi46

A hydrogen-containing inorganic clathrate with the nominal composition, K7(H2)3Si46, has been prepared in 98% yield by the reaction of K4Si4 with NH4Br. Rietveld refinement of the powder X-ray diffraction data is consistent with the clathrate type I structure. Elemental analysis and 1H MAS NMR confirmed the presence of hydrogen in this material. Type I clathrate structure is built up from a Si framework with two types of cages where the guest species, in this case K and H2, can reside: a large cage composed of 24 Si, in which the guest resides in the-6d position, and a smaller one composed of 20 Si, in which the guest occupies the 2a position (cubic space group Pm3 n). Potassium occupancy was examined using spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM). The highangle annular dark-field (HAADF) STEM experimental and simulated images indicated that the K is deficient in both the 2a and the 6dsites. 1H and 29Si MAS NMR are consistent with the presence of H2 in a restricted environment and the clathrate I structure, respectively. FTIR and 29Si{1H} CP MAS NMR results show no evidence for a Si-H bond, suggesting that hydrogen is present as H2 in interstitial sites. Thermal gravimetry (TG) mass spectrometry (MS) provide additional confirmation of H2 with hydrogen loss at ～400 °C.

The thermodynamic properties of CoCl2-NaBr and CoCl2-KBr melts

Boiling temperatures were measured at different pressures for CoCl2-NaBr and CoCl2-KBr melts of various compositions by the method of boiling points under isobaric conditions. The experimental data were described by the equation log p = B - A/T. Dependences with negative deviations from the Raoult law were obtained. The thermodynamic properties of the melts were calculated.

Synthesis and thermolysis of tris(triethoxysiloxy)aluminum and its complexes with potassium and sodium triethoxysilanolates

Reaction of potassium (or sodium) triethoxysilanolate with AlBr 3 in benzene in a 3:1 or 4:1 ratio yields, respectively, tris(triethoxysiloxy)aluminum Al[OSi(OEt)3]3 or potassium (or sodium) tetrakis(triethoxysiloxy)alumin