EPR spectroscopy elucidates the electronic structure of [FeV(O)(TAML)] complexes. Issue 15 (12th July 2021)

• Record Type: Journal Article
• Authors: Kim, Yujeong; Kim, Jin; Nguyen, Linh K.; Lee, Yong-Min; Nam, Wonwoo; Kim, Sun Hee
• Is Part Of: Inorganic chemistry frontiers. Volume 8:Issue 15(2021)
• Page Start: 3775
• Page End: 3783
• Publication Date: 2021-07-12
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1qi00522g
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : The complete hyperfine tensor of 17 O of the Fe V -oxo moeity was probed by ENDOR spectroscopy. The EPR spectroscopic results reported here provide a conclusive experimental basis for elucidating the electronic structure of the Fe V -oxo complex. Abstract : Multifrequency, multitechnique pulse EPR spectroscopy was employed to unravel the spin Hamiltonian parameters of 17 O in the [Fe V O] moiety with two different tetraamido macrocyclic ligands (TAMLs), [Fe V (O)(TAML-1)] − (1, H4 (TAML-1) = 3, 4, 8, 9-tetrahydro-3, 3, 6, 6, 9-hexamethyl-1 H -1, 4, 8, 11-benzotetraazocyclotridecane-2, 5, 7, 10-(6 H, 11 H )-tetrone) and [Fe V (O)(TAML-2)] − (2, H4 (TAML-2) = H4 [(Me2 CNCOCMe2 NCO)2 CMe2 ]), to investigate the electronic structure of Fe V -oxo species. Although rigorous computational studies on high-valent iron-oxo species have been reported recently, experimental evidence to explicate the electronic structure of Fe V -oxo species is sparse. In particular, a complete hyperfine tensor of 17 O can hardly be detected. Herein, we successfully probed the hyperfine tensor of 17 O of the Fe V -oxo moiety using ENDOR spectroscopy. Hence, the EPR spectroscopic results reported here provide a conclusive experimental basis for elucidating the electronic structure of the Fe V -oxo complex. Moreover, the reactivity of the two different complexes is very distinct, and our results may provide insight into how their electronic structure contributes to their reactivity.