Spontaneous Reduction of Mononuclear High‐Spin Iron(III) Complexes to Mononuclear Low‐Spin Iron(II) Complexes in Aqueous Media and Nuclease Activity via Self‐Activation |
| |
| Authors: | Dr. Kaushik Ghosh Dr. Nidhi Tyagi Ashish Kumar Dhara Dr. Udai P. Singh |
| |
| Affiliation: | Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee‐247667 Uttarakhand (India) |
| |
| Abstract: | Mononuclear high‐spin [FeIII(Pyimpy)Cl3]?2 CH2Cl2 ( 1 ?2 CH2Cl2) and [FeIII(Me‐Pyimpy)Cl3] ( 2 ), as well as low‐spin FeII(Pyimpy)2](ClO4)2 ( 3 ) and [FeII(Me‐Pyimpy)2](ClO4)2 ( 4 ) complexes of tridentate ligands Pyimpy and Me‐Pyimpy have been synthesized and characterized by analytical techniques, spectral, and X‐ray structural analyses. We observed an important type of conversion and associated spontaneous reduction of mono‐chelated high‐spin FeIII ( 1 ?2 CH2Cl2 and 2 ) complexes to low‐spin bis‐chelated FeII complexes 3 and 4 , respectively. This process has been explored in detail by UV/Vis, fluorescence, and 1H NMR spectroscopic measurements. The high positive potentials observed in electrochemical studies suggested a better stabilization of FeII centers in 3 and 4 . Theoretical studies by density functional theory (DFT) calculations supported an increased stabilization for 3 in polar solvents. Self‐activated nuclease activity of complexes 1 ?2CH2Cl2 and 2 during their spontaneous reduction was examined for the first time and the mechanism of nuclease activity was investigated. |
| |
| Keywords: | ABTS oxidation density functional calculations iron complexes self‐activated nuclease spontaneous reduction |
|
|
