7782-78-7 Usage
Chemical Properties
Nitrosylsulfuric acid, HNO5S, is a straw-colored, oily liquid furnished as a 40% solution in 87% sulfuric acid,and stable at room temperature. It is used as a diazotizing agent for dyes,chemical intermediate, drugs and pharmaceuticals.
Physical properties
Nitrosylsulfuric acid is produced as an intermediate in the manufacture of sulfuric acid using the lead chamber process by the reaction of sulfur dioxide, nitrogen dioxide, oxygen, and water. Nitrosylsulfuric acid also is made from absorption of nitrogen oxides (NOx) in oleum (fuming sulfuric acid): N2O3 + 2H2SO4 → 2ONSO4 + H2O or by the reaction of nitrosyl chloride with concentrated sulfuric acid: ClNO + H2SO4 → ONSO4 + HCl Another method of preparation involves the reaction of nitrosyl bromide with silver bisulfate: AgHSO4 + BrNO → ONHSO4 + AgBr In making disperse azo dyes, nitrosylsulfuric acid is produced by the addition of sodium nitrite, NaNO2, to concentrated sulfuric acid (1g NaNO2 per 13 g H2SO4).
Uses
Different sources of media describe the Uses of 7782-78-7 differently. You can refer to the following data:
1. Nitrosylsulfuric acid (40?wt. % in sulfuric acid) is a reagent used for the preparation of new heterocyclic disperse azo dyes.
2. For bleaching cereal milling products.
3. Nitrosylsulfuric acid is used for diazotisation, nitrosation, oxidation and oximation reactions. Product Data Sheet
General Description
Shipped in solution with sulfuric acid (solutions are usually 40% Nitrosylsulfuric acid and 54% sulfuric acid (Hawley)). Solution is a straw-colored oily liquid with a sharp odor. When pure, a crystalline solid decomposing at 73°C. Very irritating to skin and eyes. Used to make dyes and other chemicals.
Reactivity Profile
Nitrosylsulfuric acid is an oxidizing agent. Neutralizes chemical bases in exothermic reactions. An attempt to diazotize dinitroaniline using Nitrosylsulfuric acid resulted in an explosion with loss of life. The event was blamed on the high concentration of the reactants dinitroaniline hydrochloride and Nitrosylsulfuric acid [MCA Case History 1763. 1971].
Health Hazard
TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
Safety Profile
A poison. A corrosive
irritant to skin, eyes, and mucous
membranes. Explosive reaction above 50°C
with 2-chloro-4,6-dinitroaniline and 4-
chloro-2,6-d1nitroalne. Potentially
explosive reaction with dmitroaniline. When
heated to decomposition it emits toxic
fumes of SOx and NOx. See also
SULFATES and NITRATES.
Check Digit Verification of cas no
The CAS Registry Mumber 7782-78-7 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 2 respectively; the second part has 2 digits, 7 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 7782-78:
(6*7)+(5*7)+(4*8)+(3*2)+(2*7)+(1*8)=137
137 % 10 = 7
So 7782-78-7 is a valid CAS Registry Number.
7782-78-7Relevant articles and documents
Synthesis and antimicrobial activities of some novel thiophene containing azo compounds
Fondjo, Emmanuel Sopbue,Tsemeugne, Joseph,De Dieu Tamokou, Jean,Djintchui, Arnaud Ngongang,Kuiate, Jules Roger,Sondengam, Beibam Luc
, p. 253 - 259 (2013)
A series of new thienylazothiophenes were prepared by coupling reactions of diazotized thienocoumarins with their corresponding free amines. The structures of the products 3-7 were assigned on the basis of their elemental and spectroscopic data. The HMBC and HSQC techniques were used in some cases to ascertain the structural assignments. The antimicrobial screenings of compounds 3-7 along with substituted 2-aminothiophenes 1a,b were performed against three bacteria and three fungal species and their activities compared to those of nystatin, gentamycin and ciprofloxacin used as reference drugs. It was found that the antimicrobial activities of the tested new hybrid compounds were in some cases equal or better than those of the reference drugs.
A combined experimental and DFT investigation of mono azo thiobarbituric acid based chalcone disperse dyes
El-Sadany, Samir K.,El-atawy, Mohamed A.,Hamed, Ezzat A.,Mahmoud, Mona N.,Omar, Alaa Z.
, (2020/10/08)
A number of monoazo dyes were synthesized by the reaction of 4-aminoacetophenone with different substituted benzaldehydes to give a new series of chalcone derivatives. The diazonium salts of these chalcones then allowed to react with thiobarbituric acid to produce the appropriate azo dye. The structures of the newly synthesized dyes were assigned by IR, NMR spectral data. IR study confirmed the existence of azo-dioxothioxo tautomer in the solid phase while 1H NMR study indicated the predominance of azoenol-oxothioxo or hydrazo-dioxothioxo tautomers. The geometries of the azo and hydrazo tautomeric forms and their electronic absorption of the dyes were optimized at B3LYP/6-311G level of theory. All the azo compounds were evaluated for their dyeing performance on polyester fibers, and PET. All the synthesized dyes gave moderate to excellent fastness properties on PET fiber. The effects of the nature of the substituents on the color and dyeing properties of these dyes have been evaluated. The mechanism of dyeing polyester fiber was discussed.
On the Reaction of 2-Benzylamino-1,4-naphthoquinones with Nitrosylsulfuric Acid
Gornostaev,Nuretdinova,Lavrikova,Khalyavina, Yu. G.,Fominykh,Gatilov, Yu. V.
, p. 608 - 614 (2019/07/17)
The reaction of 2-benzylamino-1,4-naphthoquinone with nitrosylsulfuric acid in acetic acid results in preferential formation of 2,1- and 2,3-heterocyclization products: (E)-4-(hydroxyimino)-2-phenylnaphtho [2,1-d]oxazol-5(4H)-one and 2-phenyl-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-dione. In addition, 2-phenylnaphtho[2,1-d]oxazol-4,5-dione and N-(3-nitro-1,4-dioxo-1,4-dihydronaphthalen-2-yl)benzamide are also formed. The reaction of 2-benzylamino-3-chloro-1,4-naphthoquinone with nitrosylsulfuric acid in acetic acid gives 3-diazonapthalene-1,2,4(3H)-trione and benzaldehyde.
