Studies on isomerism of 1 : 2 iron complexed dye based on 1-(5 '-nitro-2 '-hydroxyphenyl)-3-cyano-5-(4 ''-sulphonamidophenyl)formazan

During the synthesis of previously described new 1:2 iron complexes of 1,5- diaryl-3-cyanoformazanes it was found that the metalisation process is depe ndent on the pH of the reaction media and in some cases two isomeric produc ts appear. These isomers exhibited the same quantitative composition but di fferent colours and physico-chemical properties. With the use of H-1-NMR an d IR analysis and the measurements of magnetic moments an attempt to attrib ute the chemical structure to both isomers of 1:2 type iron complex of 1-(5 '-nitro-2'-hydroxyphenyl)-3-cyano-5-(4 " -sulphonamidophenyl)formazan has b een made. (C) 2000 Elsevier Science Ltd. All rights reserved.