Spectroscopic investigation of indole-3-acetic acid interaction with iron(III)

Fe-III was found to be gradually reduced by indole-3-acetic acid (IAA) in s lightly acidic nitrate solution with further reoxidation of the resulting F e-II upon drying in air, which is reasoned to be of ecological significance considering IAA excretion by many soil micro-organisms. Fe-III-IAA complex was isolated; its composition. some physicochemical properties and structu ral aspects were studied using Mossbauer, FTIR spectroscopic and other tech niques. Possible influence of Fe-III coordination on the redox properties o f the ligand is also considered from the viewpoint of the nature of the bon ding system which involves the conjugated pi -electronic system of the pyrr ole cycle along with the carboxylic O-donor atom. (C) 2001 Elsevier Science B.V. All rights reserved.