Electronic Structure of Manganese(III) Compounds from High‐Frequency EPR Spectra

Abstract

The use of high magnetic field and high frequency in an unconventional spectrometer has provided very informative EPR spectra of a manganese(III) octahedral complex for the first time. The parameters of the spin Hamiltonian operator are in fair agreement with those calculated with ligand‐field theory. High‐frequency EPR is thus a powerful tool for the structural investigation of complexes that contain metal ions with integer spins.

A perspective on applications of ligand-field analysis: inspiration from electron paramagnetic resonance spectroscopy of coordination complexes of transition metal ions

“…In particular, a Mn III tris(β-diketonate) complex was the subject of a complete ligand-field analysis by Barra et al, 79 providing AOM parameters. Many other Mn III complexes have been studied by HFEPR since then.…”

Properties of Manganese(III) Ferrocenyl-β-Diketonato Complexes Revealed by Charge Transfer and Multiplet Splitting in the Mn 2p and Fe 2p X-Ray Photoelectron Envelopes

“…Paramagnetic high-spin metal species show significant multiplet splitting [10]. The full width at half maximum (FWHM) of the photoelectron lines of these high-spin metals are broader than those of their low-spin counterparts-e.g., high spin Mn(III) vs. low spin Mn(II) [5]. These complex photoelectron lines can be deconvoluted with multiplet splitting peaks as demonstrated by Gupta and Sen [8,9] and others [11][12][13].…”

“…Properties of metal(III) β-diketonato complexes [M(R 1 COCHCOR 2 ) 3 ], M = metal and R = pendant β-diketonato side groups such as CH 3 , have been studied with a variety of different techniques including crystallography [1], electrochemistry [2], non-linear refractive measurements [3], UV-Vis spectroscopy [4], and high frequency electron paramagnetic resonance (EPR) [5]. However, characterization of these complexes by means of X-ray photoelectron spectroscopy (XPS) is not well established.…”

Jahn-Teller distortion in tris[4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionato]manganese(III) isomers: An X-ray and computational study

“…This result encouraged us to similarly determine the crystal structure of another [Mn(β-diketonato) 3 ] complex, at both RT and LT. This study therefore presents the crystal structures of the [Mn(tfth) 3 ] complex, where tfth = (CF 3 COCHCOC 4 H 3 S) − , both at RT and at an LT of 150 K. The experimentally obtained crystal structures are complemented by a density functional theory study, to obtain insight into the electronic structure of this high spin 3d 4 Mn(III) complex.…”

“…Crystal structures of different tris(β-diketonato)manganese(III) complexes exhibit elongation JahnTeller distortion [2,3,4] or compression Jahn-Teller distortion [5,6,7]. Reported structures of [Mn(acetylacetonato) 3 ] include three different crystalline forms: namely a β form obtained at room temperature, which exhibited a moderate compression (TC) of the metal-ligand bonds along the zaxis of about 0.05 Å [5]; secondly, a γ form, also obtained at room temperature (RT), which showed a significant elongation (TE) of the metal-ligand bonds along the z-axis of about 0.18 Å [2]; and thirdly, a δ form, obtained at low temperature (LT) (100K), exhibiting a Jahn-Teller orthorhombic distortion [8].…”