Selective oxidation of benzyl alcohol to benzaldehyde, 1‐phenylethanol to acetophenone and fluorene to fluorenol catalysed by iron (II) complexes supported by pincer‐type ligands: Studies on rapid degradation of organic dyes

Abstract

Hexacoordinated non‐heme iron complexes [Fe II (L 1 ) 2 ](ClO 4 ) 2 ( 1 ) and [Fe II (L 2 ) 2 ](PF 6 ) 2 ( 2 ) have been synthesized using ligands L 1 = (E)‐2‐chloro‐6‐(2‐(pyridin‐2ylmethylene) hydrazinyl)pyridine and L 2 = (E)‐2‐chloro‐6‐(2‐(1‐(pyridin‐2‐yl)ethylidene)hydrazinyl) pyridine]. These complexes are highly active non‐heme iron catalysts to catalyze the C (sp 3 )−H bonds of alkanes. These iron complexes have been characterized using ESI−MS analysis and molecular structures were determined by X‐ray crystallography. ESI − MS analysis also helped to understand the generation of intermediate species like Fe III −OOH and Fe IV =O. DFT and TD−DFT calculations revealed that the oxidation reactions were performed through high‐valent iron center and a probable reaction mechanism was proposed. These complexes were also utilized for the degradation of orange II and methylene blue dyes.