Premium
Interaction of copper ion with some food dyes
Author(s) -
Banerjee Tara S.,
Roy Bidhan R.,
Majee Biswadev
Publication year - 1977
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740280503
Subject(s) - metal , chemistry , salt (chemistry) , copper , molecule , metal ions in aqueous solution , ion , inorganic chemistry , photochemistry , organic chemistry
The nature of the complexes formed by Cu 2+ with some food dyes has been studied spectrophotometrically under varied conditions. The results indicated formation of 1:1 metal: dye species at pH 4.5 and of 2:1 metal: dye species at higher pH. The latter result is unexpected and surprising since in most cases azo dyes form 1:1 or 1:2 metal: dye species and no example of a metal complex having more than one metal atom per dye molecule has so far been reported. This curious observation has been rationalised in terms of a salt forming Cu 2+ ion and a coordinated Cu 2+ ion per dye molecule; tentative structures for these species have also been proposed. It is hoped this novel finding will stimulate further investigations into the metal‐dye complexes.