title: 1H, 13C, NH, HH, CH COSY, HH NOESY NMR and UV-vis studies of Solophenyl red 3BL dye azo-hydrazone tautomerism in various solvents.
abstract: Azo-hydrazone tautomeric behavior of polyazo Solophenyl red 3BL (C.I. Direct 80) dye in different solvents (water, methanol and DMSO) was investigated using 1H, 13C, NH, HH, CH COSY, HH NOESY NMR techniques and UV-vis spectroscopy. Two-dimensional NMR experiments were used to assign 1H, 13C and 15N NMR lines unambiguously. Results showed that the hydrazone-form proton NMR signal appeared in the weakest field with respect to tetramethylsilane, in comparison with the amide and phenolic proton NMR signals. UV-vis absorption spectroscopic evidences showed that azo-hydrazone mixture exists in water and DMSO solvents, but in methanol, only azo tautomer was dominant, which was in a good agreement with NMR spectroscopic results.
authors.affiliation: Department of Chemistry, University of Isfahan, Hezar Jerib Street, Isfahan 81745-73441, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Hassanzadeh
authors.forename: A
authors.initials: A
authors.lastname: Zeini-Isfahani
authors.forename: M H
authors.initials: MH
authors.lastname: Habibi
authors.forename: M R A Poor
authors.initials: MR
authors.lastname: Heravi
authors.forename: M
authors.initials: M
authors.lastname: Abdollahi-Alibeik
mesh_terms: D001391:Azo Compounds / Q000032:analysis* / Q000737:chemistry*; D002247:Carbon Isotopes; D004396:Coloring Agents / Q000032:analysis* / Q000737:chemistry*; D017666:Deuterium Oxide; D004121:Dimethyl Sulfoxide; D006835:Hydrazones / Q000032:analysis / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic; D006859:Hydrogen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009587:Nitrogen Isotopes; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
chemical_list: D001391:Azo Compounds; D002247:Carbon Isotopes; D004396:Coloring Agents; D006835:Hydrazones; D006841:Hydrocarbons, Aromatic; D009587:Nitrogen Isotopes; C509104:Solophenyl red 3BL; D012997:Solvents; D006859:Hydrogen; D017666:Deuterium Oxide; D004121:Dimethyl Sulfoxide