Pentagonal Bipyramidal First-Row Transition Metal Complexes with Macrocyclic Ligand Containing Two Pyridine- N -Oxide Pendant Arms: Structural, Magnetic, and Theoretical Studies
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide A heptadentate 15-membered pyridine-based macrocyclic ligand containing two pyridine- N -oxide pendant arms ( L4 = 3,12-bis((pyridine-1-oxide-2-yl)methyl)-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),14,16-triene) was synthesized together with its first-row transition metal complexes with the general formula [M( L4 )](ClO 4 ) 2 ·1DMF (M II = Mn ( 1 ), Fe ( 2 ), Co ( 3 ), and Ni ( 4 ); DMF = N, N’ -dimethylformamide), which were thoroughly investigated. According to the obtained X-ray crystal structures, all complexes possess axially compressed pentagonal bipyramidal geometry with a coordination number of 7 for 1 – 3 or 5 + 2 for Ni(II) complex 4 with a large Jahn–Teller distortion. Fe(II), Co(II), and Ni(II) complexes 2, 3, and 4 show pronounced magnetic anisotropy ( D = 4.47, 30.10, −7.58 cm –1, respectively). The magnetic properties of the studied complexes were supported by theoretical calculations, which corresponded very well to the experimental data for magnetic anisotropy. Furthermore, complex 3 showed a field-induced single-molecule magnet behavior described best by the combination of direct ( DH m = 145 K –1 s –1 ) and Raman ( C = 0.58 K –n s –1 for n = 5.76) relaxation processes. Magneto-structural correlation for Fe(II)/Co(II)/Ni(II) complexes with L4 and previously studied structurally similar ligands revealed a significant impact of the coordination ability of the functional group in pendant arms on the final magnetic anisotropy (π-acceptors appear to be more suitable).
Source: Inorganic Chemistry
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G142395220, Vplyv redukovanej rozmernosti na spinovo-fonónovú interakciu, G398242923, Photoswitchable Single Molecule Magnets and Spin Crossover Complexes for the Surface Deposition, Terapia svetlom - žiarením aktivované komplexy prechodných kovov zamerané na interakciu s DNA, Semicoordination: a route to chemically stable molecular nanomagnets, Bioaktívne komplexy prechodných kovov s magnetickou bistabilitou, Novel Magnetically Bistable Cobalt(II) and Iron(II) Hofmann-like Polymers for Surface Deposition
OpenAlex ID: W4416602177