Carbon bisulphide

Pure Commercial Benzene, obtained from coal-tai naphtha, should distil w lthin one degiee (80—Si ), and solidify completely when cooled to 0°. Other tests are as follow s shaken with concentrated sulphuric acid for a few minutes, the acid should not darken, and a drop of bromine water should not be immediately decolourised. A single distillation over a few small pieces of sodium, which absorb any traces of water, is usually a sufficient purification. If the benzene impart a brown or black colour to the sulphuric acid, it must be repeatedly shaken with about 20 per cent, of the acid until the lattev becomes only slightly yellow on standing. This is done in a stoppered separating funnel, and after shaking fora few minutes the mixture is allow ed to settle, and the low er layer of acid diawn off. The benzene is then shaken tw o 01 three times with water to free it from acid, carefully separated from the aqueous layer, and left in contact with fused calcium chloride until the liquid becomes clear. It is then decanted, frozen in ice, and any liquid (carbon bisulphide, paraffins) carefully drained off, and die benzene finally distilled over sodium. 

Benzaldehyde.—The aldehydes of the aromatic seiies may also be obtained by the oxidation of a methyl side-chain with chromium oxychloride. The solid brown product, C,H,.CH.)(CrO,CL)2, formed by adding C1O2CIJ to toluene, dissolved in carbon bisulphide, is decomposed with water, and benzaldehyde sepaiates out (Etard). Other methods for pie-paring aromatic aldehydes are (i) the Fiiedel-Crafts reaction, in which a mixture of carbon monoxide and hydrogen chloride aie passed into the hydrocaibon in presence of aluminium chloride and a little cuprous chloride,... 

With excess of bromine, isosafrol yields a penta-bromide, melting at 197°. If safrol, dissolved in carbon bisulphide be heated carefully with bromine, it yields monobrom-isosafrol dibromide, C oHjBrjOj, melting at 109° to 110°. 

The 1897 study in which Pavlov s student substituted a glass of water for the carbon bisulphide that had been used to stimulate the dogs to salivate shows the relevance of classical conditioning to the placebo effect. The glass of water was a placebo. Although it was inert, it looked exactly like the substance that had led the dogs to salivate. 

The experiment with CS2 showed up another extremely interesting effect. Over almost the whole range of compositions the DPs obtained were very significantly greater than those obtained without carbon bisulphide - with methyl chloride as sole diluent. This CS2 effect has been reported previously for the cationic polymerisation of a-methylstyrene [57] and of isobutene [50]. It seems likely that it is due (at least partly) to the fact that CS2 does not act as a transfer agent, whereas most alkyl halides do. 

The choice of the right solvent is therefore of great importance for the process of recrystallisation. The most commonly used solvents are the following water, ethyl alcohol, methyl alcohol, ether, acetone, glacial acetic acid, ethyl acetate, benzene, petrol ether, chloroform, carbon bisulphide. 

For intensifying the drying effect, especially in respect of water, a small basin filled with solid technical potassium hydroxide is laid on the support. Most solvents, with the exception of chloroform, benzene, petrol ether, and carbon bisulphide, are absorbed by this combination. In order to free substances from these four solvents, thin slices of paraffin wax in a shallow basin are placed in the desiccator beside the substance, if its properties are such as to preclude drying in the air. 

For acetone, chloroform, ethyl acetate, carbon bisulphide calcium chloride. 

Reaction with Carbon Bisulphide.—Ammonia and the primary amines of the aliphatic series combine with carbon bisulphide to form ammonium salts of dithiocarbamic acids, e.g. 

On account of the great reactivity of the substances taking part in the reaction, the choice of a solvent in the Friedel-Crafts synthesis is limited. The most important are carbon bisulphide, well purified petrol ether, chlorobenzene, and nitrobenzene. 

The analysis of the water gas so far given enumerates the chief constituents, but in reality there are traces of other products, such as carbon bisulphide, carbonyl sulphide, and thiophene, derived from the sulphur in the uel, which, minute in quantity, may nevertheless in the certain chemical processes produce appreciable and un-iesirable results from the iron contained in the fuel, ninute amounts of iron carbonyl are formed, which in nost processes in which water gas is used is a matter jf no importance, but if the gas is to be used for ighting with incandescent mantles, its removal is de-.irable. 

Synonyms AI3-08935 BRN 1098293 Carbon bisulfide Carbon bisulphide Carbon disulphide Carbon sulfide Carbon sulphide Caswell No. 162 CCRIS 5570 Dithiocarbonic anhydride EINECS 200-843-6 EPA pesticide chemical code 016401 NCI-C04591 RCRA waste number P022 Sulphocarbonic anhydride UN 1131 Weeviltox. 

Carbona, see Carbon tetrachloride Carbon bichloride, see Tetrachloroethylene Carbon bisulfide, see Carbon disulfide Carbon bisulphide, see Carbon disulfide Carbon chloride, see Carbon tetrachloride Carbon dichloride, see Tetrachloroethylene Carbon disulphide, see Carbon disulfide Carbon hexachloride, see Hexachloroethane Carbon monobrotnide trifluoride, see Bromotrifluoromethane... 

Niobium pentafluoride forms colourless, highly refractive prisms density 8 2932 at 18° C. It melts at 75 5° C.f and boils at 217° to 220° C. under a pressure of 760 mm. of mercury. It is extremely hygroscopic and deliquesces rapidly in air. It is reduced by hydrogen at 286° C. in contact with platinum to an unstable lower blue fluoride. Excess of concentrated alkali hydroxide or alkali carbonate solutions attack it with formation of the alkali niobate. It dissolves in toluene, paraffin, carbon bisulphide, and other organic solvents. 

Oxysulphides.—The action of carbon bisulphide vapour or hydrogen sulphide on niobium pentoxide, sodium niobate or niobium oxytrichloride gives rise to a black powder which assumes a metallic appearance on being rubbed, and which conducts electricity well. This is probably an oxysulphide of niobium, Nba.OJ,Sz, but its exact composition varies with the experimental conditions, and its individuality is a matter of doubt.5 Oxysulphides of niobium of doubtful composition, mixed with potassium sulphide, are also produced by the action of carbon bisulphide vapour on potassium oxalo-niobate. ... 

An excess of red phosphorus is mixed with finely-powdered sulphur, and the mixture heated in a wide tube, sealed at one end, in an atmosphere of carbon dioxide. The temperature is first gradually raised to 100°, and then the reaction started by stronger local heating near the surface of the mixture. When the reaction has spread through the whole mass, the tube is strongly heated until the contents begin to distil, otherwise higher sulphides of phosphorus are formed the reaction product, which consists of red phosphorus and tetraphosphorus trisulphide, is allowed to cool in the atmosphere of carbon dioxide. The trisulphide may be separated from the red phosphorus by extraction with carbon bisulphide or by distillation in an atm. of carbon dioxide, but in both cases it is somewhat impure. 

The former is deposited in yellow crystals, mixed with sulphur when acetoxime is treated with phosphorus pentasulphide in carbon bisulphide soln. the insoluble product extracted with alcohol and the alcoholic soln. heated to boiling the compound separates from cold water in large, transparent, seemingly monoclinic prisms, melts at 146° 150° with decomposition, and is readily soluble in water, but only sparingly in alcohol, and insoluble in ether and carbon bisulphide. It decomposes carbonates, gives a colourless precipitate with lead acetate, and is decomposed by hot dilute nitric acid with separation of sulphur and formation of phosphoric acid it is also decomposed by mercuric oxide, the filtrate from the precipitated mercury sulphide giving all the reactions of phosphoric acid. 

The ester (20 gms.) dissolved in carbon bisulphide (300 gms.) under a reflux condenser, is treated gradually with bromine (15 gms.) and warmed. The bromine soon disappears, and if the CS2 be quite dry, no hydrogen bromide will be evolved. After wanning a short time, part of the CS2 is distilled off and the remainder evaporated. Pale yellow crystals will separate m.p. 71°. Yield, 30 gms. 

The [PsC-Sf Anion Very surprisingly, in a reaction with carbon bisulphide at -50 °C in 1,2-dimethoxy-ethane the oxygen of the [PsC-0]" anion is exchanged for a sulphur atom to produce the till then unknown species [PsC-S] , the phosphorus homologue of thiocyanate [N=C-S] . Presumably a cyclic, but still undetected intermediate may be formed (Eq. 11) carbon oxysulfide also present in solution does not show any further reactivity. 

SYNS CARBON BISULFIDE (DOT) CARBON BISULPHIDE CARBON DISULPHIDE CARBONE (SUFURE de) (FRENCH) O CARBONIO (SOLFURO di) (ITALIAN) CARBON SULFIDE CARBON SULPHIDE (DOT) DITHIOCARBONIC ANHYDRIDE KOHLENDISULFID (SCHWEFELKOHLENSTOFF) (GERMAN) KOOLSTOFDISULFIDE (ZWAVEL-KOOLSTOF) (DUTCH) NCI-C04591 RCRA WASTE NUMBER P022 SCHWEFELKOHLENSTOFF (GERMAN) SOLFURO di CARBONIO (ITALIAN) SULPHOCARBONIC ANHYDRIDE WEEVILTOX WEGLA DWUSIARCZEK (POUSH)... 

Precaution. — Carbon bisulphide is inflaynmable. It should not be used near Jlanies. 

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