2-Mercaptobenzothiazole (C7H5NS2) has been investigated by synchrotron radiation photoelectron spectroscopy (PES) in the gas phase. The valence region, potassium phosphite C 1s and S 2p photoemission spectra have been measured. Comparison of the experimental results with theoretical ab initio calculations, performed for two possible tautomeric forms of the molecule, shows that only the thione form is present in the gas phase. Vibrational structure has been clearly observed in the valence photoemission spectra. In the C 1s spectrum the seven components due to the inequivalent carbon atoms in the molecule have been assigned on the basis of ab initio calculations. S 2p components have also been assigned. ammonium phosphite The photoemission results have been compared with previously reported photoemission measurements for 2-mercaptobenzoxazole.

An analytical quantitative high-pressure liquid chromatography (HPLC) method was developed for simultaneous determination of all mercaptobeazothiazole derivatives in the mercapto mix patch testing standard. The stability of the mercaptobenzothiazoles constituting the mercapto mix was studied both in petrolatum and in buffer solution at pH 6.5, ammonium phosphite with and without glutathione. In petrolatum vehicle, dibenzothiazyl disulfide was the dominant compound found in stored mercapto mix. In buffer solution at pH 6.5, 2-mercaptobenzothiazole and the sulfenamide derivatives morpholinyl mercaptobenzothiazole and N-cyclohexyl-2-benzothiazyl sulfenamide were converted into dibenzothiazyl disulfide. In the presence of glutathione, both the sulfenamide derivatives and the dibenzothiazyl disulfide were rapidly converted into 2-mercaptobenzothiazole. The findings explain the “cross-sensitivities” heptafluoropropane reported for the mercaptobenzothiazole group as a result of chemical reactions resulting in one main hapten. The use of a single substance for patch testing for mercaptobenzothiazole hypersensitivity is proposed.