1
|
Yureva EA, Korchagin DV, Anichkin AA, Shilov GV, Babeshkin KA, Efimov NN, Palii AV, Aldoshin SM. Evidence for zero-field slow magnetic relaxation in a Co(II) complex with a pseudo-tetrahedral N 2I 2 environment. Dalton Trans 2022; 51:11916-11921. [PMID: 35876183 DOI: 10.1039/d2dt01336c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Herein, we report on the synthesis, structure and magnetic properties of a four-coordinate mononuclear Co(II) diiodide complex with the 3,5-dimethylpyrazole ligand. A distorted tetrahedral local coordination environment around the central cobalt ion is formed by the two nitrogen atoms of two monodentate pyrazole ligands and by iodide ions. Direct current (dc) magnetic measurements in combination with ab initio SA-CASSCF/NEVPT2 quantum-chemical calculations revealed a strong easy-axis-type magnetic anisotropy with a record value Dexp = -30.58(3) cm-1 of the axial zero field splitting parameter for pseudo-tetrahedral Co(II)-based CoL2Hal2 complexes. Moreover, it is the only complex in this series demonstrating the slow relaxation of magnetization at zero dc field. The Orbach process is shown to be the dominant mechanism of magnetic relaxations in the high temperature range, while the quantum tunneling of magnetization produces the leading contribution to the overall relaxation at temperatures below 4 K.
Collapse
Affiliation(s)
- E A Yureva
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia.
| | - D V Korchagin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia.
| | - A A Anichkin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia. .,Faculty of Fundamental Physical and Chemical Engineering, Moscow State University, 1-3, Leninskiye Gory, 119991 Moscow, Russia
| | - G V Shilov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia.
| | - K A Babeshkin
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 31, Leninsky prosp., 119991 Moscow, Russia
| | - N N Efimov
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 31, Leninsky prosp., 119991 Moscow, Russia
| | - A V Palii
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia.
| | - S M Aldoshin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov prosp., 142432 Chernogolovka, Moscow Region, Russia.
| |
Collapse
|
2
|
Korchagin DV, Gureev YE, Yureva EA, Shilov GV, Akimov AV, Misochko EY, Morgunov RB, Zakharov KV, Vasiliev AN, Palii AV, Lohmiller T, Holldack K, Aldoshin SM. Field-induced single-ion magnet based on a quasi-octahedral Co(II) complex with mixed sulfur-oxygen coordination environment. Dalton Trans 2021; 50:13815-13822. [PMID: 34519734 DOI: 10.1039/d1dt02413b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH2)[Co(TDA)2] 2H2O (I), (pipH22+ = piperazine dication, TDA2- = thiodiacetic anion) are described. X-ray diffraction studies reveal the first coordination sphere of the Co(II) ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur-oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency-domain Fourier-transform (FD-FT) THz-EPR spectroscopy, and high-level ab initio SA-CASSCF/NEVPT2 quantum chemical calculations reveal a strong "easy-plane" type magnetic anisotropy (D ≈ +54 cm-1) of complex I. The complex shows field-induced slow relaxation of magnetization at an applied DC field of 1000 Oe.
Collapse
Affiliation(s)
- D V Korchagin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - Ya E Gureev
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432. .,M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - E A Yureva
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - G V Shilov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - A V Akimov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - E Ya Misochko
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - R B Morgunov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - K V Zakharov
- M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - A N Vasiliev
- M.V. Lomonosov Moscow State University, Moscow 119991, Russia.,National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - A V Palii
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432. .,Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev, Moldova
| | - T Lohmiller
- EPR4Energy Joint Lab, Department Spins in Energy Conversion and Quantum Information Science, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - K Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - S M Aldoshin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| |
Collapse
|