Sulfo salts

Schwefel-natrium, -natron, n. sodium sulfide, -nickel, m. nickel sulfide, -niederschlag, m. precipitate of sulfur, precipitated sulfur, -ofen, m. sulfur burner, -oxyd, n. (any) sulfur oxide, -phosphor, m. (any) phosphorus sulfide, -probe, /. sulfur sample mercury sulfide, -quelle, /. sulfur spring, -rducherung, /. sulfur fumigation, -rubin, m. ruby sulfur, realgar, -salz, n. sulfur salt, thio salt, sulfo salt sulfate. 

Sulfo-olsaure, /. sulfodleic acid, -persaure, /. peroxysulfiiric acid, persulfuric acid, -salz, n. thio salt, sulfo salt. 

A large number of salts are known which are collectively designated as thio or sulfo salts. These may be classified in various ways, and several types will be described in the following exercises. 

Groth, P. H. R. (1908). Chemische kristallographie. Zweiter teil.Die anorganischen 0X0- und sulfosalze [Chem. crystallography. Second part. Inroganic oxy- and sulfo salts]. W. Engelemann, Leipzig. [10, 18]... 

Separation. — From most of the metals, germanium may be separated by the formation of the sulfo-salts with ammonium sulfide. It may be separated from arsenic, antimony, and tin by exactly neutralizing the sulfo-salts with sulfuric acid and filtering after 12 hours. Evaporate to small bulk, add ammonia, ammonium sulfate, and sulfuric acid and saturate with H. GeS2 precipitates while the other metals remain in solution. 

Dwight Dana and Edward Salisbury Dana, Vol. 1, Elements, Sulfides, Sulfo-salts, Oxides, 7th ed., Wiley, New York, 1944. 

The familiar principle that binary reactions can frequently be used for the detection of either of the reactants is not limited to reactions conducted in liquid media. Recently it has been found that AsgSg or AsgSg are produced when a mixture of elemental arsenic and sulfur is heated at 110° C. The sulfur melts and then reacts. This synthesis of arsenic sulfides followed by treatment with ammonia (formation of ammonium sulfo salts) permits the detection of As or S (see pages 111 and 436). 

Compounds that contain divalent sulfur (thiosulfates, thiocyanates and sulfo salts) catalyze the irreversible redox reaction ... 

All solid metal sulfides, natural or synthetic, and also the sulfo salts (e.g., HgCl2 2HgS and similar addition compounds of sulfides) react immediately with sodium azide solutions with evolution of nitrogen. They may thus be detected in the presence of sulfates, sulfites, free sulfur, sele-nides, etc. 

Procedure. A drop of the test solution and a drop of 2 % mercuric chloride solution are stirred together on a spot plate. If excess HgCl2 is present, the white mercuric sulfo salt (2 HgS-HgClj) is formed. A little solid potassium chloride is mixed in. Litmus paper dipped into the liquid turns red if thiosulfate is present. 

Docusate Calcium. Dioctyl calcium sulfosuccinate [128-49-4] (calcium salt of l,4-bis(2-ethylhexyl)ester butanedioic acid) (11) is a white amorphous soHd having the characteristic odor of octyl alcohol. It is very slightly soluble in water, and very soluble in alcohol, polyethylene glycol 400, and com oil. It may be prepared directly from dioctyl sodium sulfo succinate dissolved in 2-propanol, by reaction with a methan olic solution of calcium chloride. 

Docusate Sodium. Aerosol OT, Colace, and Doxinate are trade names of docusate sodium [577-11-7] (dioctyl sodium sulfo succinate, sodium salt of l,4-bis(2-etliylhexyl)estet butanedioic). This white, wax-like, plastic sohd, with a characteristic odor suggestive of octyl alcohol, is usually available in the form of pellets. One gram of the sodium salt slowly dissolves in about 70 mL water. Docusate sodium is freely soluble in alcohol and glycerol, very... 

Chemical Properties and Reactivity. LLDPE is a saturated branched hydrocarbon. The most reactive parts of LLDPE molecules are the tertiary CH bonds in branches and the double bonds at chain ends. Although LLDPE is nonreactive with both inorganic and organic acids, it can form sulfo-compounds in concentrated solutions of H2SO4 (>70%) at elevated temperatures and can also be nitrated with concentrated HNO. LLDPE is also stable in alkaline and salt solutions. At room temperature, LLDPE resins are not soluble in any known solvent (except for those fractions with the highest branching contents) at temperatures above 80—100°C, however, the resins can be dissolved in various aromatic, aUphatic, and halogenated hydrocarbons such as xylenes, tetralin, decalin, and chlorobenzenes. 

Naphthol AS Coupling Components. Naphthol AS components are the aryhdes of either o-hydroxyarylcarboxycHc acids or acylacetic acids. They are free of sulfo and carboxyl groups, but form salts with bases these salts dissolve in water to give colloidal solutions, which couple with diazo components to form colored pigments. The whole class derives from the anilide of 3-hydroxy-2-naphthoic acid [92-70-6] Naphthol AS (85) (Cl Azoic Coupling Component 2). 

Benzofurazan, 7-chloro-4-nitro-, 6, 394 as fluorigenic agents, 6, 410, 426 Benzofurazan, 4-chloro-7-sulfo-ammonium salt properties, 6, 426 Benzofurazan, 4-nitro-synthesis, 6, 408 Benzofurazans, 6, 393-426 Beckmann fragmentation, 6, 412 biological activity, 6, 425 bond angles, 6, 396 bond lengths, 6, 396 diazo coupling, 6, 409 dipole moments, 6, 400 electrochemical reduction, 5, 73 electrophilic reactions, 6, 409-410 ESR spectroscopy, 6, 400... 

Calcon carboxylic acid [3-hydroxy-4-(2-hydroxy-4-sulfo-l-napbtbylazo)napbtbalene-2-carboxylic acid] [3737-95-9] M 428.4, m 300°, X,max 560nm, pKj 1.2, pK2 3.8, PK3 9.26, PK4 13.14. Purified through its p-toluidinium salt. The dye was dissolved in warm 20% aq MeOH and treated with p-toluidine to ppte the salt after cooling. Finally recrystd from hot water. [Itoh and Ueno Analyst (London) 95 583 1970.] Patton and Reeder (Anal Chem 28 1026 1956) indicator and complexes with Ca in presence of Mg and other metal ions. 

Indigocarmine (2[l,3-dihydro-3-oxo-5-sulfo-2ff-indol-2-ylidene]-2,3-dihydro-3-oxo-lff-indole-5-sulfonic acid di-Na salt) [860-22-0] M 466.4, pK 2.8, pK2 12.3. Its... 

Zincon (o-[l-(2-bydroxy-5-sulfo)-3-phenyl-5-formazono]-benzoic acid) [135-52-4] M 459.4. Main impurities are inorganic salts which can be removed by treatment with dilute acetic acid. Organic contaminants are removed by refluxing with ether. It can be recrystd from dilute H2SO4. [Fichter and Schiess Chem Ber 33 751 1900.]... 

Zincon disodium salt (o-[l-(2-bydroxy-5-sulfo)-3-pbenyl-5-formazono]-benzoic acid di-Na salt) [135-52-4, 56484-13-0] M 484.4, m -250-260 (dec). Zincon soln is prepared by dissolving 0.13g of the powder in aqueous N NaOH (2mL diluted to lOOmL with H2O). This gives a deep red colour which is stable for one week. It is a good reagent for zinc ions but also forms stable complexes with transition metal ions. [UV-VIS Bush and Yoe Anal Chem 26 1345 1954 Hunter and Roberts J Chem Soc 820 1941 Platte and Marcy Anal Chem 31 1226 1959] The free acid has been recrystd from dilute H2SO4. [Fichter and Scheiss Chem Ber 33 751 1900.]... 

Other direct methods for the sulfonation of the higher fatty acids are by the use of sulfur trioxide vapor or by the use of chlorosulfonic acid. Indirect methods are also available for the preparation of a-sulfo fatty acids and their salts from an a-bromo fatty acid made by the Hell-Volhard-Zelinsky reaction. The bromo compound may be converted directly to the sodium salt of a sulfonic acid through the Strecker reaction or may be converted to the mercaptan and oxidized to the sulfonate. Sulfonation of the lower fatty acids has been studied by Backer and co-workers. ... 

Treatment of the dithiete 175 with Meerwein reagent yielded the sulfo-nium salt 212 in high yield (99UP1). 

Rhodanld, n. thiocyanate, (formerly) sulfo-cyanate( esp. an -ic salt cf. Rhodantlr),... 

Stanni-ozyd, n, stannic oxide, tin(IV) oxide, -reihe, /. stannic series, tin(IV) series, -salz, n. stannic salt, tin(IV) salt, -sulfo-zyanid, n. stannic thiocyanate, tin(IV) thiocyanate. -verbindung, /, stannic compound, tin(IV) compound,... 

The a-sulfo fatty acid esters are obtained by a-sulfonation of the fatty acid esters, and in basic mediums they form the corresponding salts. 

Nagayama et al. [36] studied a-sulfonation using nuclear magnetic resonance (NMR). They reported the presence of two intermediates. The first intermediate is the adduct of S03 to the carbonyl oxygen formed at low temperatures. In contrast to the mechanism of Stein et al., they did not propose a rearrangement of this intermediate but a second addition of S03 to the activated a-hydrogen to give the second intermediate. The reaction of the intermediate with sodium hydroxide can lead to the disodium salt if the neutralization is immediate or to the sodium a-sulfo fatty acid ester if the neutralization is delayed. 

Neutralization leads to the salt of the a-sulfo fatty acid ester, but only if the neutralization step is delayed. If the neutralization is immediate the a-sulfonated anhydride forms a disalt of the a-sulfo fatty acid as a byproduct [38]. The production of the disalt is also effected by the ratio between S03 and the ester. A high surplus of S03 would shorten the reaction time, but the amount of disalt in the end product would increase. For 90°C and 30 min an optimal S03/es-ter ratio is 1.2 1 [37]. 

Besides these normal technical products, many other different types of a-sulfo fatty acid esters have been described in the literature. For example, Weil et al. prepared a-sulfopalmitates and stearates with higher alcohols [19] and also monoesters of polyhydric alcohol [39] and of hexitols and sucrose [40] for their special properties. In addition to the sodium salt, Stirton et al. used other cations, such as Li, NH4, K, Mg, and Ca, to study the relationship between the structure and the surfactant properties [30]. 

In the literature a number of different techniques for the preparation of a-sulfo fatty acid esters can be found. There is equipment for small-scale and commercial scale sulfonation. Stirton et al. added liquid sulfur trioxide dropwise to the fatty acids dispersed or dissolved in chloroform, carbon tetrachloride, or tetrachoroethylene [44]. The molar ratio of S03/fatty acid was 1.5-1.7 and the reaction temperature was increased to 65 °C in the Final stage of sulfonation. The yield was 75-85% of the dark colored a-sulfonated acid. The esterification of the acid was carried out with either the a-sulfonic acid alone, in which case the free sulfonic acid served as its own catalyst, or with the monosodium salt and a mineral catalyst. 

Even if the fatty acid esters have been sulfonated under optimal conditions the ester sulfonates are dark-colored [12,33] so the sulfonated product has to be bleached. The second pretreatment is the neutralization of the acid product to obtain the salt of the a-sulfo fatty acid ester. Different techniques have been published in the literature. Kapur et al. suggested bleaching with 3-4 wt % NaOCl (15 wt % solution) after neutralization with a 30% aqueous solution of sodium hydroxide. This technique is for small-scale sulfonation [46]. 

Because of their preferential use as detergents, the main interest in the physicochemical properties of the salts of a-sulfo fatty acid esters is related to their behavior in aqueous solution and at interfaces. In principle these are surface-active properties of general interest like micelle formation, solubility, and adsorption, and those of interest for special applications like detergency, foaming, and stability in hard water. 

For the disodium salts of the a-sulfo fatty acids it was found that the Krafft points are higher than those of the a-ester sulfonates. Because the CMC is also higher for the disalts they are more soluble than ester sulfonates at low temperatures but less soluble at higher temperatures [58]. 

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