ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Acid-base equilibriums of several azo compounds in dimethylsulfoxide. II. Study of several phenylazo and naphthylazo derivatives of 7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzothiazoles in DMSO and their use for titrations in DMSO

E. Kozáková, E. Kuchár, and P. Majer

Lehrstuhl für Analytische Chemie der Naturwissenschaftlichen Fakultät an der Komenský-UniversitäU 801 00 Bratislava

Abstract:  Acid-base properties of the following five substituted phenylazo compounds of 7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazole: of l-(7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazolyl-2-azo)-4-hydroxy 2,5-dimethylbenzene (DTA/), of l-(7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazolyl-2-azo)-4-hydroxy-2,6-dimethylbenzene (DTA II), of 1-(7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazoIyl-2-azo)-4-hydroxy-2-methyl-5-isopropylbenzene (DTAIII), of 1-(7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazolyl-2-azo)-2-hydroxy-4,5-dimethyIbenzene (DTA IV) and of 1-(7-oxo-5,5-dimethyl-4,5,6,7-tetrahydrobenzthiazolyl-2-azo)-2-naphthol (DTA V) in dimethyl sulfoxide (DMSO) are described. Dissociation constants of these compounds and molar absorption coefficients of particular forms in DMSO were determined by the spectrophotometric method. Compounds DTA 1—DTA V can be utilized as acid-base indicators for the determination of bases in DMSO.

Full paper in Portable Document Format: 303a366.pdf (in German)

Chemical Papers 30 (3) 366–376 (1976)