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Updated: Oct 17, 2025
Setup of Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry CE-ICP-MS for Quantification of Iron Redox Species FeII, FeIII
Published on: May 4, 2020
Application of Lever's EL Parameter Scale toward Fe(II)/Fe(III) versus Pc(2-)/Pc(1-) Oxidation Process Crossover
Victor N Nemykin1,2, Dustin E Nevonen2, W Ryan Osterloh3
1Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.
Abstract:
The electronic structures and, particularly, the nature of the HOMO in a series of PcFeL2, PcFeL'L″, and [PcFeX2]2- complexes (Pc = phthalocyaninato(2-) ligand; L = NH3, n-BuNH2, imidazole (Im), pyridine (Py), PMe3, PBu3, t-BuNC, P(OBu)3, and DMSO; L' = CO; L″ = NH3 or n-BuNH2; X = NCO-, NCS-, CN-, imidazolate (Im-), or 1,2,4-triazolate(Tz-)) were probed by electrochemical, spectroelectrochemical, and chemical oxidation as well as theoretical (density functional theory, DFT) studies. In general, energies of the metal-centered occupied orbitals in various six-coordinate iron phthalocyanine complexes correlate well with Lever Electrochemical Parameter EL and intercross the phthalocyanine-centered a1 orbital in several compounds with moderate-to-strong π-accepting axial ligands. In these cases, an oxidation of the phthalocyanine macrocycle (Pc(2-)/Pc(1-)) rather than the central metal ion (Fe(II)/Fe(III)) was theoretically predicted and experimentally confirmed.
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