4’- -azobenzene-4-sulfonic acid sodium salt

CAS 6408-78-2 EINECS/ELINCS 229-068-1 Synonyms 1-Amino-9,10-dioxo-4-phenylamino-9,10-dihydroanthracene-2-sulfonic acid, sodium salt 2-Anthracenesulfonic acid, 1-am i no-9,10-d i hyd ro-9,10-d i oxo-4-(phenylamino)-, monosodium salt Cl 62055 Classification Azobenzene Empirical C2oHi4N2NaOsS Properties M.w. 417.39 Toxicology Irritating to eyes, skin, and respiratory system TSCA listed Uses Dye for wool, silk, polyamide, leather, and soaps... 

CAS 5858-39-9 EINECS/ELINCS 227-490-0 Synonyms Acid red 4, monosodium salt Cl 14710 4-Hydroxy-3-(2-methoxyphenylazo) naphthalene-1-sulfonic acid, sodium salt 1-Naphthalenesulfonic acid, 4-hydroxy-3-((2-methoxyphenyl) azo)-, monosodium salt Classification Azobenzene Empirical Ci7Hi4N2Na05S Properties M.w. 381.35 Toxicology TSCA listed Uses Dye for wool, paper Manuf./Distnb. Aldrich http //www.sigma-aidrich.com, Sigma... 

CAS 1658-56-6 EINECS/ELINCS 216-760-3 Synonyms Cl 15620 Ext. D C Red. no. 8 Fast red A 4-(2-Hydroxynaphthalen-1-ylazo) naphthalene-1-sulfonic acid, sodium salt 4-((2-Hydroxy-1 -naphthalenyl) azo)-1 -naphthalene sulfonic acid sodium salt 1-Naphthalenesulfonic acid, 4-((2-hydroxy-1-naphthalenyl) azo)-, monosodium salt Red no. 506 Rocceline Roccelline Solid red A Classification Azobenzene Empiricai C2oHi4N2Na04S Properties M.w. 401.41 m.p. 280 C Toxicoiogy Mutagen TSCA listed Storage Store in cool, dry place keep container closed when not in use... 

Chippendale et al.m studied 13C and 15N CP/MAS NMR of free acids and sodium salts of a series of sulfonated azobenzene dyestuffs (39). In solution the spectra of both free acid and salts are characteristic of /rani-azobenzene structures, as are the spectra of the solid samples of the salts. The spectra of the solid free acids are markedly different from those of the corresponding solid sodium salts (Tables 17 and 18) and exist as azonium tautomers (three resonance structures are shown for 39f). Solid-state structures of this type are probably stabilized by the formation of intermolecular bonds. 

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