The ¹³C NMR titration shifts of sulphonic acids

Abstract

Carbon-13

Determination of alkylbenzenesulfonates and alkylsulfates as anionic surfactants by carbon-13 nuclear magnetic resonance spectrometry

“…The Cj peak of the aromatic ring is affected very much by the sulfonic group, but little by various of para-substituted alkyl groups. The single peak observed at 143.5 ppm agrees with a chemical shift calculated (143.1 ppm) based on additivity (7) of chemical shifts of n-butylbenzene (8) and benzenesulfonic acid (5).…”

“…Besides clear distinction between similar structures, another advantage of 13C NMR analyses of ABS lies in the easiness of sample preparation because chemical shifts are independent of pH values of aqueous solutions (5).…”

“…Since almost nothing is required prior to measurements, NMR spectroscopy often facilitates analyses of compounds such as organic sulfates, sulfonic acids, and carboxylic acids (4) for which hydrolyses or esterifications are needed in GLPC analyses. Our basic research on alkylsulfonic acids by 13C NMR (5) has now been extended to the present compounds.…”

Competitive inclusion of chloro-substituted acetic acids into β-cyclodextrin monitored by rotational correlation frequencies of 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxy radical

“…Carbon-13 nmr spectra were taken on a Varian XL-100 spectrometer. Pulse conditions have been described elsewhere (12). Sample concentrations were 3 x mol/L in a solvent mixture of H,O and DMSO-d, in the ratio of 1 to 1 which increased solubilities and stabilized the magnetic field at the same time.…”