Magnetic properties and electronic structure of five- and six-coordinate manganese(II)2,6-bis (benzimidazol-2-yl) pyridine complexes

verfasst von: Wolfgang Linert, Franz Renz, Roman Boca
Abstract: Two manganese(II) complexes with the terdentate ligand 2,6-bis(benzimidazol-2-yl)pyridine, namely [Mn(bzimpy)₂(ClO₄)₂], 1 and [Mn(bzimpy)Cl₂]·0.5MeOH, 2, have been investigated by magnetic susceptibility measurements in the temperature range 18 to 300 K. Electron spin resonance has been measured in solid state and frozen solution at 77 K. Parameters for the magnetic contributions to the Hamiltonian obtained by these techniques confirm axial magnetic anisotropy. ACS data are: g_av = 1.92 ± 0.04, lD/hcl = 0.9 ± 1.3 cm^-1 and g_av = 1.89, lD/hcl = 1.4 cm^-1 for 1 and 2, respectively. The three found ESR resonances correspond to g_eff(1) = 1 99, g_eff(2) = 3.3 and g_eff(3) = 4.3. The highest field resonance exhibits a hyperfine sextet splitting of lA_av/hcl = 92 × 10^-4 cm^-1 for both complexes. Well resolved forbidden transitions allow for an estimation of the zero-field splitting parameter being D/hc = -0.09 and 0.13 cm^-1 for the two complexes, respectively. Ab initio MO-LCAO-SCF calculations on a double-zeta basis set indicate that complex 2 should be more stable than 1. The calculations also yielded information on electronic structure, bond-strengths and charge distribution within the complexes.
Organisationseinheit(en): Institut für Anorganische Chemie
Externe Organisation(en): Technische Universität Wien (TUW)
Slowakische Technische Universität Bratislava (STU)
Typ: Artikel
Journal: Journal of coordination chemistry
Band: 40
Seiten: 293-309
Anzahl der Seiten: 17
ISSN: 0095-8972
Publikationsdatum: 1996
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Physikalische und Theoretische Chemie, Werkstoffchemie
Elektronische Version(en): https://doi.org/10.1080/00958979608024534 (Zugang: Unbekannt)

BibTeX

@article{1b687ca74dc848178f073ceae58f866d,
title = "Magnetic properties and electronic structure of five- and six-coordinate manganese(II)2,6-bis (benzimidazol-2-yl) pyridine complexes",
abstract = "Two manganese(II) complexes with the terdentate ligand 2,6-bis(benzimidazol-2-yl)pyridine, namely [Mn(bzimpy)2(ClO4)2], 1 and [Mn(bzimpy)Cl2]·0.5MeOH, 2, have been investigated by magnetic susceptibility measurements in the temperature range 18 to 300 K. Electron spin resonance has been measured in solid state and frozen solution at 77 K. Parameters for the magnetic contributions to the Hamiltonian obtained by these techniques confirm axial magnetic anisotropy. ACS data are: gav = 1.92 ± 0.04, lD/hcl = 0.9 ± 1.3 cm-1 and gav = 1.89, lD/hcl = 1.4 cm-1 for 1 and 2, respectively. The three found ESR resonances correspond to geff(1) = 1 99, geff(2) = 3.3 and geff(3) = 4.3. The highest field resonance exhibits a hyperfine sextet splitting of lAav/hcl = 92 × 10-4 cm-1 for both complexes. Well resolved forbidden transitions allow for an estimation of the zero-field splitting parameter being D/hc = -0.09 and 0.13 cm-1 for the two complexes, respectively. Ab initio MO-LCAO-SCF calculations on a double-zeta basis set indicate that complex 2 should be more stable than 1. The calculations also yielded information on electronic structure, bond-strengths and charge distribution within the complexes.",
keywords = "Benzimidazole, E.s.r, Magnetochemistry, Manganese(II)",
author = "Wolfgang Linert and Franz Renz and Roman Boca",
note = "Funding Information: Thanks are due to the fonds {\textquoteleft}Zur Forderung der wissenschaftlichen Forschung in Ostereich{\textquoteright} (Project 10818). the Slovak Grant Agency and to the exchange program between Austria and Slovakia (Project 6 Os3) for financial support.",
year = "1996",
doi = "10.1080/00958979608024534",
language = "English",
volume = "40",
pages = "293--309",
journal = "Journal of coordination chemistry",
issn = "0095-8972",
publisher = "Taylor and Francis Ltd.",
number = "4",
}