Hydrogen sulflde

Chlorine dioxide Ammonia, carbon monoxide, hydrogen, hydrogen sulflde, methane, mercury, nonmetals, phosphine, phosphorus pentachloride... 

Chromic(VI) acid Acetic acid, acetic anhydride, acetone, alcohols, alkali metals, ammonia, dimethylformamide, camphor, glycerol, hydrogen sulflde, phosphorus, pyridine, selenium, sulfur, turpentine, flammable liquids in general... 

Copper Acetylene and alkynes, ammonium nitrate, azides, bromates, chlorates, iodates, chlorine, ethylene oxide, fluorine, peroxides, hydrogen sulflde, hydrazinium nitrate... 

Hydrogen sulflde Euming nitric acid, oxidizing gases, peroxides... 

Nitric acid, fuming Organic matter, nonmetals, most metals, ammonia, chlorosulfonic acid, chromium trioxide, cyanides, dichromates, hydrazines, hydrides, HCN, HI, hydrogen sulflde, sulfur dioxide, sulfur halides, sulfuric acid, flammable liquids and gases... 

Nitrogen trichloride Ammonia, As, hydrogen sulflde, nitrogen dioxide, organic matter, ozone, phosphine, phosphorus, KCN, KOH, Se, dibutyl ether... 

Nitrogen triiodide Acids, bromine, chlorine, hydrogen sulflde, ozone... 

Oxidative microcoulometry has become a widely accepted technique for the determination of low concentrations of sulfur in petroleum and petroleum products (ASTM D3120). The method involves combustion of the sample in an oxygen-rich atmosphere followed by microcoulometric generation of a triiodide ion to consume the resulting sulfur dioxide. It is intended to distinguish the technique from reductive microcoulometry, which converts sulfur in the sample to hydrogen sulflde that is titrated with coulometrically generated silver ion. 

The reaction with hydrogen sulflde leads to the formation of trisulfanes (84). Condensations with alcohols proceed very smoothly to thioper-oxides (3,110) ... 

Also heterocyclic flavour molecules can be formed from renewable resources. 3,5-Diethyl-1,2,4-trithiolane is an important molecule for onion flavours and can easily be prepared from propanal obtained by biotransformation and hydrogen sulflde (Scheme 13.17). A meat flavour molecule like thialdine [dihydro-2,4,6-trimethyl-l,3,5(4H)-dithiazine] can be prepared from acetaldehyde isolated from molasses and ammonium sulflde (Scheme 13.18). The bacon flavour substance 2,4,6-triisobutyl-5,6-dihydro-4H-l,3,5-dithiazine can be prepared from isovaleraldehyde prepared from essential oils and ammonium sulfide (Scheme 13.19). 

Hydrogen sulflde gas was passed into a solution of 6-[4-cyano-3-(elhoxymelhyleneamino)-phenyl]-5-methyl-4,5-diliydropyridazin-3(2//)-one (19.5 g, 68.6 mmol) and EijN (25 mL, 179 mmol) in pyridine (250 mL) for 30 min at rt with stirring, i he precipitated crystals were collected by filtration, washM with H O, and dried to afford the crude product yield 13.0 g (70%) mp >300 C (DMF/HjO). 

Methyl-2-oxo-l, 2-dihydropyrazine with phosphorus pentasulfide in pyridine at reflux was converted into l-methyl-2-thio-l,2-dihydropyrazine (18) (821,1100), and 3-chloropyrazine 1-oxide with sodium hydrogen sulflde in ethanol at room temperature gave 3-mercaptopyrazine 1-oxide (19) (1035). Whereas 3-chloro-2,5-dimethyipyrazine 1-oxide reacted slowly with thiourea in ethanol, and the use of water in place of ethanol caused some increase in reaction rate, the reaction in 2A sulfuric acid at reflux for 30 minutes gave 3-mercapto-2,5-dimethylpyrazine 1-oxide (85%), and 3-mercapto-2-methylpyrazine 1-oxide was prepared similarly (905). 

Dimethyl monothiomaleate (56) and monothiofumarate (57) are formed in a complicated reaction from 2,5-dimethoxythiophene via an intermediate of the orthoester type. 0-Trimethylsilyl ketene-0,0-acetals are readily formed from carboxylic esters and can be transformed to thioxoesters, without being isolated, by reaction with hydrogen sulflde, according to equation (34). Methyl thioxoarachido-nate (58) was prepared by this route. ... 

Reactions of phosgene with hydrogen sulflde and hydrogen selenide... 

Hydrogen sulflde (H ). Tungsten powder reacts at 350-500 °C according to W + 2H2S -> WS2 -F 2H2. At low temperature, the hexagonal modification forms. 

In the only reversible approach [144], quatemized acridinium was immobilized on a solid support such as cellulose. In slightly alkaline medium, hydrogen sulflde adds to the strongly fluorescent dye and renders it nonfluorescent. Interferences by ionic quenchers may be eliminated by covering the sensor with a 4-pm silicone-rubber membrane which is permeable to gases but not to ions. The detection limit is of the order of 0.1 mmol L. ... 

Chemical.—In its chemical characters I resembles Cl and Br, "but is less active. It decomposes HaO slowly, and is a weak bleaching and oxidizing agent. It decomposes hydrogen sulfld... 

Chemical.—Sulfur unites readily with other elements, especially at high temperatures. Heated in air or O, it burns with a blue flame to sulfur dioxid, SOa. In H it burns with formation of hydrogen sulfld, HaS. The compounds of S are similar in constitution, and to some extent in chemical properties, to those of 0. In many organic substances S may replace O, as in sul-focyanio acid, CNSH, corresponding to cyanic acid, CNOH. 

Analytical Characters.—Staxxous.—(1.) Potash or soda white-ppt. soluble in excess the solution deposits Sn when boiled. (2.) Ammonium hydroxid white ppt. insoluble in excess turns olive-brown when the liquid is boiled. (3.) Hydrogen sulfld dark brown ppt. soluble in KHO, alkaline sulflds, and hot HjO. (4.) Mercuric chlorid white ppt. turning gray and black. (5.) Auric chlorid purple or brown ppt., in presence of small quantity of HNOi. (6.) Zinc deposit of Sn. 

Analytical Characters.—(1.) Hydrochloric acid white, floccu-lent ppt. soluble in NH,HO insoluble in HNOs. (2.) Potash or soda brown ppt. insoluble in excess soluble in NH,HO. (3.) Ammonium hydroxid, from neutral solutions brown ppt. soluble in excess. (4.) Hydrogen sulfld or ammonium sulfliydrate black ppt. insoluble in NH4HS. (.3.) Potassium bromid yellowish-white ppt. insoluble in acids, if not in great excess soluble in NH, . (6.) Potassium iodid same as KBr, but the ppt. is less soluble in NH,HO. 

Analytical Characters.—(1.) K, Na or NH hydroxid white ppt., soluble in excess.- (2.) Carbonate of K or Na white ppt., in absence of NH< salts. (3.) Hydrogen sulfld, in neutral solution white ppt. In presence of an excess of a mineral acid, the formation of this ppt. is prevented, unless sodium acetate be also present. (4.) Ammonium sulfhydrate white ppt., insoluble in excess, in KHO, NHtHO, or acetic acid soluble in dilute mineral acids. (5.) Ammonium carbonate white ppt., soluble in excess. (6.) Disodic phosphate, in absence of NHj salts white ppt., soluble in acids or alkalies. (7.) Potassium ferrocyanid white ppt., insoluble in HCl. 

Analytical Characters.—Hydrogen sulfld bright yellow ppt. insoluble in NH HS, and in dilute acids and alkaUes, soluble in boiling HNO3 or HCl. 

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