Sulphonic Acids and Salts

Foaming of urea - formaldehyde resins for cavity wall insulation Alkylbenzene sulphonic acids and salts Foaming agents... 

Nansa Series Alkyl benzene sulphonic acids and salts Olefin sulphonates... 

Rhodacal Series Alkyl aryl sulphonic acids and salts... 

Sulphonic Acids. Benzylthiouronium salts (p. 359), Sulphonamides and sulphonanilides (p. 354). 

To prepare the free sulphinic acid, dissolve some of the sodium salt in cold water and cautiously acidify with hydrochloric acid avoid an excess of mineral acid since it dissolves the sulphinic acid to a certain extent. The resulting p-tolueneaulphinic acid is difflcult to dry without partial conversion into the sulphonic acid and thiolsulphonic ester... 

Group II. The classes 1 to 5 are usually soluble in dilute alkali and acid. Useful information may, however, be obtained by examining the behaviour of Sails to alkaline or acidic solvents. With a salt of a water-soluble base, the characteristic odour of an amine is usually apparent when it is treated with dilute alkali likewise, the salt of a water soluble, weak acid is decomposed by dilute hydrochloric acid or by concentrated sulphuric acid. The water-soluble salt of a water-insoluble acid or base will give a precipitate of either the free acid or the free base when treated with dilute acid or dilute alkali. The salts of sulphonic acids and of quaternary bases (R4NOH) are unaflFected by dilute sodium hydroxide or hydrochloric acid. 

Sulphonic acids. The aromatic sulphonic acids and their alkali metal salts are soluble in water, but insoluble in ether (Solubility Group II). They are best characterised by conversion into crystalline S-benzyl-iso-thiuronium salts (see Section IV,33,2 and 111,85,5), which possess characteristic melting points. A more time-consuming procedure is to treat the well-dried acid or... 

Basic compound To neutralise strong mineral acids (from fuels) Barium or basic calcium salts of sulphonic acids and alkylsalicylic acid. Superbasic and hyperbasic additives are basic salts with a large excess of base... 

Typical ion-pairing reagents are, for cations, alkyl sulphonic acids, eg pentane, hexane, heptane or octane sulphonic acid, and for anions, tetrabutylammonium or dibutylamine ammonium salts. In ion-pair chromatography the retention of solutes can be controlled in a number of ways ... 

Fig. 3.130. HPLC chromatograms of the test mixture detected by DAD (270 nm, upper lane) by APCI-MS-TIC (middle) and by ESI-MS-TIC (lower lane). Peak identification l=benzene sulphonic acid sodium salt 2=2-naphtalene sulphonic acid sodium salt 3=2-anthraquinone sulphonic acid sodium salt 4 = sulphorhodamine D sodium salt 5=crocein orange G 6=eriochrome black T 7=2,6-anthraquinone disulphonic acid disodium salt 8 = 1,5-naphtalene disulphonic acid disodium salt 9 = azophloxine 10 = 1,2-benzene disulphonic acid dipotassium salt. Reprinted with permission from G. Socher et al. [178].

Two series of complex iridium salts corresponding to the hexammino-and diacido-iridium salts have been prepared containing ethylene-diamine. These have the same general characteristics as the ammino-salts. Both series have been resolved into optically active isomers, the dinitrito-series by means of d- and 1-bromo-camphor sulphonic acid, and the triethylenediamino-series by d- and 1-nitro-camphor. Attempts have been made to prepare etliylenediamino-derivatives containing tetravalent iridium. Thus, sodium hexaehloro-iridate, [IrCl6]Na2, reacts with ethylenediamine, but the products are syrupy and cannot be purified. Derivatives of trivalent iridium, however, have been prepared. These are crystalline and fairly easily purified. The... 

Benzaldehyde-2-sulphonic acid sodium salt [1008-72-6] M 208.2. Forms prisms or plates by extracting with boiling EtOH, filtering, evaporate to dryness and recrystallise the Na salt from a small volume of H2O. The N-phenylhydrazone sodium salt recrysts from H2O, m 174.5°. [A 299 363 1898]. 

Dihydro-3,4-dioxo-l-naphthlene sulphonic acid sodium salt (l,2-naphthoquinone-4-sulphonic acid sodium salt) [521-24-4] M 260.2. Yellow crystals from aqueous EtOH and dry at 80° in vacuo. Solubility in H2O is 5% Synth Coll Vol III 633 1955 Danielson JBC 101 507 1933 UV Rosenblatt et al. AC 27 1290 7955]. 

Naphthol Yellow S (citronin A, flavianic acid sodium salt, 8-hydroxy-5,7-dinitro-2-naphthalene sulphonic acid disodium salt) [846-70-8] M 358.2, dec on heating. Greenish yellow powder soluble in H2O. The free sulphonic acid can be recrystd from dil HCl (m 150°) or AcOH-EtOAc (m 148-149.5°). The disodium salt is then obtained by dissolving the acid in two equivalentss of aqueous NaOH and evaporating to dryness and drying the residue in a vacuum desiccator. The sodium salt can be recrystd from the minimum volume of H2O or from EtOH [Dermer and Dermer JACS 61 3302 1939]. 

Cryoscopic measurements on the acid in benzene, etc., indicate a mixture of single and double molecules. Single molecules of thiocyanie acid may be represented by the formula NsC — SH or S C=NH. Probably the inorganic salts and the esters derived from them have the constitution represented by the first formula. The esters are converted into sulphonic acids and hydrocyanic acid by oxidation,... 

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