Complex Formation with Trivalent Iron and N,N′-Ethylene bis[2(o-hydroxyphenyl)] Glycine

Abstract

N,N′-Ethylene bis [2(o-hydroxyphenyl)] glycine (EHPG) is one of the analogues of ethylenediamine tetraacetic acid (EDTA) which has aroused increasing interest recently as a reagent forming very stable chelates with many metal ions. The ferric complex is particularly valuable for treating iron chlorosis in plants, as the use of the corresponding EDTA chelate is restricted to crops grown on acid and only moderately weak alkaline soils, but the ferric-EHPG complex is effective in correcting the mineral deficiency in plants grown on alkaline soils. Moreover, use of the ferric chelate has become important in analytical chemistry as a sensitive reagent for iron^1,2. The compound has a red colour suitable for spectrophotometrie determinations.