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

During the synthesis of previously described new 1:2 iron complexes of 1,5-diaryl-3cyanoformazanes it was found that the metalisation process is dependent on the pH of the reaction media and in some cases two isomeric products appear. These isomers exhibited the same quantitative composition but different colours and physico-chemical properties. With the use of 1H-NMR and IR analysis and the measurements of magnetic moments an attempt to attribute the chemical structure to both isomers of 1:2 type iron complex of 1-(5ʹ-nitro-2ʹ-hydroxyphenyl)-3-cyano-5-(4ʹʹsulphonamidophenyl)formazan has been made.