Sulfur containing sulfonate groups

Sulfation and Sulfonation. a-Olefin reactions involving the introduction of sulfur-containing functional groups have commercial importance. As with many derivatives of olefins, several of these products have appHcations in the area of surfactants (qv) and detergents. Typical sulfur reagents utilized in these processes include sulfuric acid, oleum, chlorosulfonic acid, sulfur trioxide, and sodium bisulfite. 

FTIR and NMR Analysis of Oxidation Products. As expected the FTIR spectra of the soluble oxidation products are dominated by the strong absorptions due to the hydroxyl and carbonyl groups of carboxylic acids. There are absorptions in the spectra which occur in the regions expected for sulfones (1350-1310 and 1160-1120 cm-1) and sulfonic acids (1420-1330 and 1200-1145 cm-1), but these are probably due to non-sulfur containing functional groups, especially carbon-oxygen bonds which are presumably present in much higher concentrations. 

In comparison to the sulfoxides (-S(=0)-), the sulfones (-S(=0)2-) are a more strongly deshielding substituent in their effect on both the adjacent aliphatic groups and on the ortho aromatic protons. Some of the relative deshielding effect of the sulfur containing functional groups are displayed. 

Furthermore, the CNP obtained by hydrolysis with sulfuric acid contain sulfonic groups, which reduce the thermal stability of nanoparticles. For this reason... 

Caro et al. [120] prepared fuel cell membranes by directly introducing sulfonic acid groups to PI LE films by EB irradiation. Pi EE films were irradiated in water under atmospheric conditions and subsequently treated with fuming sulfuric add. Evidence of the presence of sulfur-containing functional groups was presented. However, no details on the basic properties of these manbranes and their fuel cell performance were reported. A summary of previous studies on radiation-grafled PCMs based on PTFE fihns and their properties are presented in Table 5.5. 

Finally, the sulfonate content of lignin is deterrnined by two main methods one typified by conductometric titration in which sulfonate groups are measured direcdy, and the other which measures the sulfur content and assumes that all of the sulfur is present as sulfonate groups. The method of choice for determining the sulfonate content of lignin samples that contain inorganic or nonsulfonate sulfur, however, is conductometric titration (45). 

Acid mixtures containing nitric acid and a strong acid, eg, sulfuric acid, perchloric acid, selenic acid, hydrofluoric acid, boron trifluoride, or an ion-exchange resin containing sulfonic acid groups, can be used as the nitrating feedstock for ionic nitrations. These strong acids are catalysts that result in the formation of nitronium ions, NO" 2- Sulfuric acid is almost always used industrially since it is both effective and relatively inexpensive. 

The aromatic sulfone polymers are a group of high performance plastics, many of which have relatively closely related stmctures and similar properties (see Polymers containing sulfur, polysulfones). Chemically, all are polyethersulfones, ie, they have both aryl ether (ArOAr) and aryl sulfone (ArS02Ar) linkages in the polymer backbone. The simplest polyethersulfone (5) consists of aromatic rings linked alternately by ether and sulfone groups. 

An example of a sulfite ester made from thionyl chloride is the commercial iasecticide endosulfan [115-29-7]. A stepwise reaction of thionyl chloride with two different alcohols yields the commercial miticide, propaigite [2312-35-8] (189). Thionyl chloride also has appHcations as a co-reactant ia sulfonations and chlorosulfonations. A patent describes the use of thionyl chloride ia the preparation of a key iatermediate, bis(4-chlorophenyl) sulfone [80-07-9] which is used to make a commercial polysulfone engineering thermoplastic (see Polymers CONTAINING SULFUR, POLYSULFONe) (190). The sulfone group is derived from chlorosulfonic acid the thionyl chloride may be considered a co-reactant which removes water (see Sulfolanes and sulfones). 

Sulfur-containing groups at an a-position stabilize carbanions. All these species, i.e., the a-sulfonyl 6281-102, a-sulfmyl 6346-80, a-sulfenyl 645,103,104 and a-sulfonio carbanions 65105-1 ancj those derived from sulfonates 66 and sulfonamides 6795 may retain their... 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

Most of the problems of side reactions can be circumvented by using a mixture of unhydrous sulfuric acid (containing no free SO3, a powerful oxidant) and orthoboric acid [4,8], The superacidic nature of this sulfonation mixture ensures complete protonation and the lack of free SO3 excludes the possibility of oxidation. In addition, the number and position of the sulfonate groups can be more effectively controlled than by using oleum for... 

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