Strassner NM, Stipurin S, Koželj P, Grin Y, Strassner T. Electronic Structure and Magnetic Properties of a High-Spin Mn
III Complex: [Mn(mesacac)
3 ] (mesacac=1,3-Bis(2,4,6-trimethylphenyl)-propane-1,3-dionato).
Chemphyschem 2023;
24:e202200652. [PMID:
36515278 PMCID:
PMC10107892 DOI:
10.1002/cphc.202200652]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/22/2022] [Indexed: 12/15/2022]
Abstract
Metal acetylacetonates of the general formula [M(acac)3 ] (MIII =Cr, Mn, Fe, Co) are among the best investigated coordination compounds. Many of these first-row transition metal complexes are known to have unique electronic properties. Independently, photophysical research with different β-diketonate ligands pointed towards the possibility of a special effect of the 2,4,6-trimethylphenyl substituted acetylacetonate (mesacac) on the electron distribution between ligand and metal (MLCT). We therefore synthesized and fully characterized the previously unknown octahedral title complex. Its solid-state structure shows a Jahn-Teller elongation with two Mn-O bonds of 2.12/2.15 Å and four Mn-O bonds of 1.93 Å. Thermogravimetric data show a thermal stability up to 270 °C. High-resolution mass spectroscopy helped to identify the decomposition pathways. The electronic state and spin configuration of manganese were characterized with a focus on its magnetic properties by measurement of the magnetic susceptibility and triple-zeta density functional theory (DFT) calculations. The high-spin state of manganese was confirmed by the determination of an effective magnetic moment of 4.85 μB for the manganese center.
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