Spectrophotometric studies on the nature of iron complexes with pyridine- and quinoline-carboxylic acids

Abstract The compositions of the ferrous iron complexes with α-picolinic, quinaldinic and quinolinic acids have been reinvestigated. In presence of potassium cyanide, iron combines with these reagents in a ratio of 1 : 1 , at pH 5.9, in absence of cyanide, the metal to reagent ratio is 1 : 2. The instability constants of the complexes are given