pH dependent catecholase activity of Fe(II) complexes of type [Fe(L)]X2 [L = N-(phenyl-pyridin-2-yl-methylene)-ethane-1,2-diamine; X = ClO4− (1), PF6− (2)]: Role of counter anion on turnover number

Abstract

Two mononuclear Fe(II) complexes having same ligand framework, coordination geometry but different counter anions [Fe(L)]X2 [L = N-(phenyl-pyridin-2-yl-methylene)-ethane-1,2-diamine; X = ClO4− (1), PF6− (2)] have been synthesized and crystallographically characterized. Both the complexes catalyzed catechol-quinone oxidation pH dependently. In the pH range 8.3–8.5 the suitable activity of both the complexes were found. Counter anions in the complexes played a significant role in controlling the turn over numbers of the catalytic reactions. In acetonitrile (MeCN), the turn over number for 1 was 4.99 h−1 and for 2, it was 42.75 h−1