Sulphates and Sulphonates

With covalent sulphates the presence of the additional oxygen atom raises the frequency still further. The numbers studied are relatively small but Detoni and Hadzi [93] proposed ranges of 1415-1380 and 1200-1185 cm K 

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Sulphate and sulphonate analogues of the carboxylates, such as the sulphobetaine 9.58, can also be used as amphoteric agents. 

Alkoxylated polysiloxanes are a relatively new class of dyebath lubricants. They have practically no substantivity for the substrate, yet combine adequate lubrication with water solubility and easy rinsability. If the silicones contain primary hydroxy groups, these can be modified by esterification, phosphation, phosphonation, sulphation, sulphonation or carboxylation. These anionic substituents confer substantivity for various substrates without losing rinsability. Anionic organic sulphates and sulphonates probably offer the best overall properties for dyebath lubricants, whilst other types can be more suitable for selected applications [464]. 

Low to medium amounts of sodium dodecyl sulphate and sulphonate make hematite hydrophobic and cause coagulation, but with higher levels of these surfactants, hematite again becomes hydrophilic and is redispersed (Fuerstenau and Colic,... 

The neutral sulphur compounds include sulphides or thioethers, disulphides, sulphoxides and sulphones, sulphate and sulphonate esters, and isothiocyanates. Acidic sulphur compounds, i.e. sulphonic and sulphinic acids, thiols and thio-phenols, and the primary sulphonamides have already been discussed. The sulphates of amines are converted by aqueous sodium hydroxide into the free bases the sulphate anion can be detected in the resulting aqueous solution as barium sulphate in the usual manner. 

Effects of added sulphate and sulphonate surfactants upon the mechanical and chemical stability of natural rubber latex (8)... 

The abilities of the sulphates and sulphonates to protect natural rubber latex against chemical destabilisation are again broadly parallel to their abilities to enhance mechanical stability. 

Fig. 7 Phosphate, phosphonate, phosphinate, sulphate and sulphonate anions...

Most aliphatic compounds are resistant to sulphonation by reaction with sulphuric acid. However, under forcing conditions some aliphatic compounds react to produce a complex mixture of sulphonic acids, sulphonic anhydrides, alkyl sulphates and sulphones. Therefore this reaction is rarely of any synthetic utility. One exception is the reaction of terminal alkynes with sulphuric acid, which yields the terminal sulphonic acid upon removal of water, as shown in equation 682. Another exception is a rather obscure report that reaction of an alkene and a nitrile with sulphuric acid, in the presence of acetic anhydride, produces 90-100% yield of the 2-amido sulphonic acid, as shown in equation 783. 

The latex agglutination immunoassay technique uses polymer colloids as a carrier for the adsorbed proteins to enhance the antigen-antibody reaction. Competitive coadsorption of immuno-gamma-globulin C-reactive protein and monomeric bovine serum albumin(m-BS A) proteins on PS latices with different functionality (sulphate and sulphonate groups) was carried out with observation of... 

J., A Comparison, S.J. (1996) A comparison of fast-atom bombardment and electrospray as methods of ionization in the study of sulphated- and sulphonated-lipids by tandem mass spectrometry. Rapid Commun. Mass Spectrom., 10,1169-1174. 

Sulphates and sulphonates are anionic at all pHs. Carboxylates are anionic only at high pH. 

Voogt [4], as long ago as 1959, used a three-column apparatus to separate anionics, soaps, cationics and nonionics. This system is still in use. The first column contained a strongly acidic cation exchanger as the free sulphonic acid. This retained cationics and converted all anions to the corresponding acids. The second column contained a strongly basic anion exchanger acetate, to retain all surface-active sulphates and sulphonates. The third column contained the same resin as the hydroxide, to retain the fatty acids. The effluent contained the nonionics. The sorbed surfactants could all be recovered by elution with hydrochloric acid. 

Phosphate esters present peculiar difficulties, because they may contain two or three of the possible esters (mono-, di- and triesters) in varying proportions. Very little information is available about their behaviour in ion-exchange systems, but it is certain that the triester will always appear in the nonionic fraction. The mono- and diesters are anions whose acid forms both contain a strongly acidic hydrogen ion, so one would expect them to behave like sulphates and sulphonates. There seems to be no published evidence for this, however. They are certainly retained by the hydroxide form of strongly basic anion exchangers. 

Anionics and any other surfactant present. Combine the two columns already described, in the order given. The first column retains sulphates and sulphonates, the second retains the amphoterics, and all other species pass through. Elute as before. 

All sulphate and sulphonate anionics except hydrocarbon sulphonates can be acid-hydrolysed. In every case but one, namely a-sulphonated fatty esters, the hydrolysis destroys their surface activity and renders them incapable of titration with benzethonium chloride. In that exceptional case, the titration per molecule is doubled by the hydrolysis. All esters are decomposed by alkaline hydrolysis or saponification, but in the case of a-sulphonated fatty esters this is not a useful measurement because of the slow hydrolysis of the sulphonate group. Also, alkanolamides, particularly dialkanolamides, are hydrolysed slowly by the normal saponification process, and although this is not a useful method of analysis for them, the possibility of generating measurable amounts of soap and alkanolamine cannot be ignored when alkali-hydrolysing anionic esters. 

Sulphonamides, sulphates and sulphonates Sulphonic acid esters... 

Sulphates and sulphonates have strong absorptions in their infrared spectra between 1250 and 1110cm (8.00-9.01 pm). 

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