Aromatic Sulphonation Research Articles

Aromatic sulphonate ion-selective electrode membrane with crystal violet as ion-exchange site

Four triphenylmethane derivatives (cations) and a high molecular-weight quaternary ammonium ion were used as the ion-exchange site in the liquid membranes of electrodes responsive to aromatic sulphonate ions, such as benzenesulphonate and α-naphthalenesulphonate. The nitrobenzene or 1,2-dichloroethane membrane containing the Crystal Violet—aromatic sulphonate pair had good sensitivity, showing an approximately Nernstian response down to 10 −4 M sulphonate. The potential of the Crystal Violet membrane was independent of pH variation from 2·5 to 12. Chloride and sulphate ions in the aqueous sample solution did not affect the electrode potential. 1,3,6-Naphthalenetrisulphonate exerted essentially no influence on the potential of the α-naphthalenesulphonate electrode. The interference of the nitrate ion was relatively large. The conductivity and association of the solute species in the membrane were estimated.

Some Quantitative Tests of Intermolecular Bonding Between Aromatic Sulphonates and Simple Carbohydrates in Water, and its Relation to Cellulose Dyeing 1

The method of continuous variations, using refractometry, shows that complexes form between sucrose in aqueous solution and non-azo aromatic sulfonates, but not between either sucrose or methyl-β-D-glucopyranoside (used as models of cellulose) and sulfonated azo dyes. Yoshida's method has been applied to determine thermodynamic parameters Entropy values of comllex formation are high, especially for the complex between sucrose and a sulfonated anthra quinone dye—probably indicating that the complexes form by face-to-face association of the molecules. It is suggested that a new type of π-bond is formed in which the π-electrons are attrated simultaneously by protons on the closely adjacent carhohydrate hydroxy-groups. This bond is not prevented by the water of solvation as are normal hydrogen bonds. The azo group appears to reduce the π-electron density in the aromatic nuclei and so prevents the bond forming The result supports the hypothesis that neither hydrogen bonds nor any form of π-bonds directly bind dyes to cellulose and is consistent with other recent work in pointing to a purely aggregation effect as the operative factor in cellulose dyeing.

Aromatic sulphonation. Part XLIII. Selenonation and sulphonation of polyalkylbenzenes with selenic and sulphuric acids in acetic anhydride

The selenonation of a series of polyalkylbenzenes with a mixture of H2SeO4 and acetic anhydride (i.e. with acetylselenic acid) at 0° has been studied. The isomer distributions of the selenonic acids are similar to those determined for sulphonation with acetylsulphuric acid as reagent. The isomer distributions indicate high selectivity for the two substitutions. The n.m.r. spectra of the polymethylbenzene-selenonic and -sulphonic acids in water are almost identical, illustrating that the shielding parameters of the SeO3– and SO3– groups on aromatic hydrogen atoms and methyl groups are about the same.

Aromatic sulphonation. Part XXXVI. The sulphuric acid sulphonation of some o-dialkylbenzenes, benzocycloalkenes, and their 4-sulphonic acids. Formation of polyxylylene from benzocyclobutene

Isomer distributions for the sulphonation of two o-dialkylbenzenes, indane, tetralin, and 6,7,8,9-tetrahydro-5H-benzocycloheptene with concentrated aqueous sulphuric acid have been determined. The 3-:4-sulphonic acid ratio decreases in the order tetralin > indane > o-xylene > 6,7,8,9-tetrahydro-5H-benzocycloheptene > o-diethylbenzene. The partial rate factors for 3-substitution by the H2S2O7 sulphonation mechanism exhibit the order tetralin ≃ indane > o-xylene > o-diethylbenzene ≃ 6,7,8,9-tetrahydro-5H-benzocycloheptene. The results of tetralin and indane are accounted for by means of a theory recently advanced to explain the Mills–Nixon effect for, e.g., protiodetritiation. The reversed order of indane and o-xylene for sulphonation as compared with protiodetritiation is ascribed to hyperconjugative stabilization of the transition state for sulphonation of indane at the 3-position. Both the lower 3 : 4 ratio and the lower f3 of o-diethylbenzene than of o-xylene and of the benzocycloheptene than of tetralin are ascribed to steric hindrance in the case of the former substrates. Sulphonation of the corresponding arene-4-sulphonic acids leads to the sole formation of the arene-3,5-disulphonic acids. In ca. 100% H2SO4 the rate order is rather similar to that of the parent hydrocarbons. The reaction of benzocyclobutene with 81–98% H2SO4 yields polyxylylene.

Aromatic sulphonation with sulphur trioxide in trichlorofluoromethane as a solvent

The sulphonation of p-dichlorobenzene with sulphur trioxide has been studied in trichlorofluoromethane as solvent. The main products are (pyro)sulphonic acid and sulphonic anhydride. The formation of sulphone is very small. The sulphonation is of first order with respect to both substrate and sulphur trioxide, and proceeds without a primary kinetic isotope effect of hydrogen ( k H/ k D = 1·08 ± at −28°). The mole-ratio of consumed sulphur trioxide to converted p-dichlorobenzene is equal to 2. It is suggested that the sulphonation proceeds via 1-benzenonium-1-sulphonate and 1-benzenonium-1-pyrosulphonate as the subsequent reactive intermediates, the formation of the former intermediate being rate limiting. The dependence of the sulphonation products on reaction time indicates that the (pyro)sulphonic acid is the initial product and that the sulphonic anhydride is formed at a later stage. The experimental data accord with formation of the anhydride by reaction of the pyrosulphonic acid with 1-benzenonium-1-sulphonate. The kinetics of sulphone formation comply with a mechanism in which ArS 3O 9 is the effective sulphonylating entity.

Aromatic sulphonation. Part XXII. Kinetic isotope effects in the reaction of [1,3,5-2H3]benzene with sulphur trioxide: competitive sulphonation of benzene and toluene

The kinetic isotope effect of hydrogen in the sulphonation of [1,3,5-2H3]benzene in trichlorofluoromethane has been determined as kH/kD= 1·23 ± 0·08 at –35°, with nitromethane as solvent kH/kD= 1·34 ± 0·08 at 20°. The kinetic isotope effect for the accompanying sulphonylation in trichlorofluoromethane was found to be kH/kD= 1·1 ± 0·1 at –35°. These results are discussed in terms of the recently established mechanism for aromatic sulphonation with sulphur trioxide in aprotic solvents. It has been determined, by competitive experiments, that the sulphonation rate ratio of toluene to benzene and the degree of para-substitution in toluene are greater with nitromethane than with trichlorofluoromethane as solvent. The apparent greater selectivity in the case of the former solvent is explained in terms of complex formation between sulphur trioxide and nitromethane.

Free-radical syntheses of sulphones from benzoyl peroxide and sulphur dioxide

The scope of the synthesis of aromatic sulphones by the decomposition of benzoyl peroxide in an organic solvent together with sulphur dioxide has been investigated. Sulphones containing groups from the solvents have been obtained from diphenylmethane, p-xylene, and acetophenone, but not from cumene, decalin, cyclohexanone, or ethyl malonate.

The photolysis of aromatic sulphones and related compounds

The photolysis of aromatic sulphones and related compounds

The Formation of Sulphonic Anhydride and Sulphone in Aromatic Sulphonation.

The Formation of Sulphonic Anhydride and Sulphone in Aromatic Sulphonation.

Aromatic sulphonation IXheterogeneous sulphonation of toluene with aqueous sulphuric acid

AbstractThe heterogeneous sulphonation of toluene with 81.9 and 95.9 wt‐% aqueous sulphuric acid has been studied at 25°. The isomer distribution which deviates from that observed in homogeneous sulphonation, varies with toluene conversion and with toluene to sulphuric acid volume ratio. The content of p‐toluenesulphonic acid is higher under heterogeneous conditions than under homogeneous conditions. It is suggested that the variation in isomer distribution is due chiefly to the presence of increasing amounts of sulphonic acids in the sulphuric acid phase.The heterogeneous sulphonation of toluene proceeds mainly in the sulphuric acid phase. Some sulphonation in the toluene phase by sulphur trioxide may take place as well. However, the latter process is of little ‐ if any ‐ importance.

Aromatic sulphonation VIII: Partial rate factors in the sulphonation of toluene with aqueous sulphuric acid

AbstractThe ratio of the overall rate constants for the sulphonation of toluene and benzene in aqueous sulphuric acid at 25° decreases from 110 to 25 on varying the acid concentration from 78 to 92 wt‐%. Similar trends are observed at 5° and 45°.The partial rate factors for ortho‐, meta‐ and para‐substitution in the sulphonation of toluene with aqueous sulphuric acid all decrease strongly with increasing acid concentration. The partial rate factor for para‐substitution is temperature independent, indicating a negligible difference in activation enthalpy between substitution at the para‐position in toluene and at a single position in benzene. The corresponding difference in activation entropies is 7 ± 2 cal · deg−1 · mole−1.The latter difference is ascribed to differences in solvation of the starting hydrocarbons or/and of the transition states. These differences in solvation may also be responsible for the small but apparent deviations from the Selectivity Relationship observed in the present study. It is suggested that the sulphonation of toluene and benzene in aqueous sulphuric acid proceeds via a Wheland type of intermediate.

Metabolism of Organic Sulfonates by Activated Sludge

Discussion of possibilities of bacterial metabolism of ABS substances in sewage; study is described in which 8 activated sludges were developed on 4 simple aromatic sulphonates and 4 analog carboxy aromatic compounds; ability of each of these activated sludges to metabolize other 7 substrates was measured with Warburg Respirometer; it is concluded that possibility to concentrate biological attack on ABS is remote.

Aromatic sulphonation IV Kinetics and mechanism of the sulphonation of benzene in aqueous sulphuric acid

AbstractThe kinetics of the sulphonation of benzene have been measured at 5.0°, 25.0° and 45.0° in aqueous sulphuric acid solutions, varying from 77.6 to 99.2 wt‐% H2SO4In addition, sulphonation rate measurements have been made at 5.0° in 98.8 wt‐% H2SO4containing various concentrations of sodium bisulphate. All reactions were found to be first order with respect to benzene. The kinetics are discussed in terms of the mechanism:magnified imageIt is suggested that sulphur trioxide or, though less probable, the sulphuric acid solvate of sulphur trioxide SO3(H2SO4) or disulphuric acid (H2S2O7), is the sulphonating entity X and thatk1 <k2|B|+k3No kinetic distinction can be made between the deprotonation by reaction [2] and the less probable intramolecular proton shift (reaction [3]).A comparison between the mechanisms of sulphonation in aqueous and fuming sulphuric acid furnishes additional evidence that SO3, instead of SO3(H2SO4) or H2S2O7, should be regarded as the sulphonating entity.

Metabolism of Organic Sulfonates by Activated Sludge

Discussion of possibilities of bacterial metabolism of ABS substances in sewage; study is described in which 8 activated sludges were developed on 4 simple aromatic sulphonates and 4 analog carboxy aromatic compounds; ability of each of these activated sludges to metabolize other 7 substrates was measured with Warburg Respirometer; it is concluded that possibility to concentrate biological attack on ABS is remote.

Aromatic sulphonation I sulphonation of benzene and toluene in aqueous sulphuric acid: (Preliminary communication)

Aromatic sulphonation I sulphonation of benzene and toluene in aqueous sulphuric acid: (Preliminary communication)

776. Aromatic sulphonation. Part V. Kinetic isotope effects and mechanism

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752. Aromatic sulphonation. Part III. Correlation of the velocity of sulphonation with the J-function of sulphuric acid

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753. Aromatic sulphonation. Part IV. Isomeric ratios in the sulphonation of trimethyl-phenyl- and -p-tolyl-ammonium methyl sulphates

753. Aromatic sulphonation. Part IV. Isomeric ratios in the sulphonation of trimethyl-phenyl- and -p-tolyl-ammonium methyl sulphates

The kinetics of aromatic sulphonation reactions; sulphonation by sulphuric acid in nitrobenzene solution.

The kinetics of aromatic sulphonation reactions; sulphonation by sulphuric acid in nitrobenzene solution.

126. The kinetics of aromatic sulphonation reactions : the sulphonation of p-nitrotoluene and of chlorobenzene by sulphur trioxide

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