Premium
A method for increasing the solubility of industrial azo pigments for 13 C and 1 H NMR spectra and the assignments of their 13 C and 1 H NMR peaks
Author(s) -
Zhu Meiling,
Feng Guangyuan,
Lv Dongjun,
Qin Nan,
Li Chunbao
Publication year - 2021
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.5138
Subject(s) - pigment , chemistry , nmr spectra database , carbon 13 nmr , proton nmr , solubility , spectral line , nuclear magnetic resonance spectroscopy , nuclear chemistry , organic chemistry , stereochemistry , physics , astronomy
A method for increasing the solubilities of industrial azo pigments in DMSO by adding DBU (1,8‐diaza‐7‐bicyclo[5.4.0]undecene) has been developed. This facilitated the acquisition of solution 13 C NMR spectra of the pigments. This method was applied to four types of azo pigments: naphthol AS (3‐hydroxy‐2‐naphthoic acid anilide) pigments, naphthol pigments, pyrazolone pigments and acetoacetanilide pigments. This represents the first solution 13 C NMR spectra for naphthol AS pigments. Altogether 18 industrial azo pigments were analysed using 1D and 2D NMR techniques. The proton and corresponding carbon NMR resonances of these pigments have all been assigned.