qualitative study of the state of some dye aggregates by using 13C and 1H-NMR spectra-1

ABSTRACT

The 13C and 1H-NMR spectra of solid as well as solutions of GI acid Red 26 and GI acid Red 27 are recorded and discussed to illustrate the structure of the dyes. Useful information is obtained about the presence of isomers and intermolecular interactions between the dye molecules. The relative shifts of dye protons are interpreted in terms of inductive and resonance interactions of substituent groups with the ring protons and with the neighboring current effects upon dilution or increasing concentration. The results indicated the presence of different molecular species of the dyes. Consequently, the spectra of the dyes could be used as a qualitative measure to study the state of dye aggregates