1
|
Biswas S, Havlicek L, Nemec I, Salitros I, Mandal L, Neugebauer P, Kuppusamy SK, Ruben M. Levamisole Based Co(II) Single-Ion Magnet. Chem Asian J 2024; 19:e202400574. [PMID: 38870468 DOI: 10.1002/asia.202400574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/13/2024] [Accepted: 06/13/2024] [Indexed: 06/15/2024]
Abstract
A new Co(II) complex, [Co(NCS)2(L)2] (1) has been synthesized based on levamisole (L) as a new ligand. Single-crystal X-ray diffraction analyses confirm that the Co(II) ion is having a distorted tetrahedral coordination geometry in the complex. Notably strong intramolecular S⋅⋅⋅S and S⋅⋅⋅N interactions has been confirmed by employing Quantum Theory of Atoms in Molecules (QTAIM). These intramolecular interactions occur among the sulfur and nitrogen atoms of the levamisole ligands and also the nitrogen atoms of the thiocyanate. Direct current (dc) magnetic analyses reveal presence of zero field splitting (ZFS) and large magnetic anisotropy on Co(II). Detailed ab initio ligand field theory calculations quantitatively predicted the magnitude of ZFS. Prominent field-induced single-ion magnet (SIM) behavior was observed for 1 from dynamic magnetization measurements. Slow magnetic relaxation follows an Orbach mechanism with the effective energy barrier Ueff=29.6 (7) K and relaxation time τo=1.4 (4)×10-9 s.
Collapse
Affiliation(s)
- Soumava Biswas
- Dr. Vishwanath Karad MIT World Peace University Survey No, 124, Paud Rd, Kothrud, Pune, 411038, Maharashtra, India
| | - Lubomir Havlicek
- Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, 61200, Brno, Czech Republic
- Institute of Physics of Materials, Czech Academy of Sciences, Zizkova 22, 61662, Brno, Czech Republic
| | - Ivan Nemec
- Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, 61200, Brno, Czech Republic
- Department of Inorganic Chemistry, Faculty of Science, Palacky University, 17. listopadu 12, 77147, Olomouc, Czech Republic
| | - Ivan Salitros
- Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, 61200, Brno, Czech Republic
- Department of Inorganic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava., Bratislava, SK-81237, Slovakia
| | - Leena Mandal
- Department of Chemistry, Polba Mahavidyalaya, Polba Hooghly, PIN-712148, West Bengal, India
| | - Petr Neugebauer
- Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, 61200, Brno, Czech Republic
| | - Senthil Kumar Kuppusamy
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Mario Ruben
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz1, 76344, Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
2
|
Yang EC, Tsai YT, Chang PY, Ozerov M, Krzystek J, Chien SY, He JX, Kuo TS, Sheu HS. Cobalt(II) Single-Ion Magnet Coordinated by Double Deprotonation of 2,2'-Bipyridine-6,6'-diol Ligands. ACS OMEGA 2024; 9:26149-26158. [PMID: 38911747 PMCID: PMC11190935 DOI: 10.1021/acsomega.4c01576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 06/25/2024]
Abstract
In this study, we synthesized a new Co(II) complex, [NMe4]2[Co(bpyO2)2] (1), using deprotonated 2,2'-bipyridine-6,6'-diol ligands (bpyO2 2-). This compound exhibits a significant zero-field splitting (D) value. The far-infrared magneto spectroscopy and high-frequency and field electron paramagnetic resonance (HFEPR) measurements indicated that compound 1 possesses D = -54.8 cm-1 and E ∼ 0 cm-1. These findings were subsequently confirmed by other experimental data, including DC magnetic susceptibilities and variable temperature and variable magnetic field reduced magnetizations. Additionally, we conducted a series of AC magnetic susceptibility measurements to investigate the kinetics of magnetization relaxation. Below 6.6 K and under zero external magnetic field, fast quantum tunneling of magnetization (QTM) dominates (∼570 Hz), and temperature-independent out-of-phase signals are observed. Above 8.1 K, temperature-dependent behavior is observed. Furthermore, we examined the AC magnetic susceptibility behavior under external magnetic fields ranging from 300 to 4000 G. The effect of QTM is significantly reduced in the presence of an external magnetic field. Temperature-dependent behavior is primarily governed by Raman relaxation. Through structural analysis of compound 1 and a series of pure nitrogen-coordinated single-ion magnets (SIMs), we propose that the oxo substituents from the double-deprotonated form of the 2,2'-bipyridine-6,6'-diol ligands donate their negative charge to the pyridine ring, forming amido anion sites. This triggers a more pronounced out-of-phase signal than that observed in pure pyridine-coordinated compounds. Moreover, we observed intermolecular interactions, including intermolecular hydrogen bonding, which, to some extent, influenced the slow relaxation of molecules. Therefore, we speculate that the slow relaxation phenomenon of compound 1 may be attributed to the combination of oxo back-donating effects and intermolecular interactions.
Collapse
Affiliation(s)
- En-Che Yang
- Department
of Chemistry, Fu-Jen Catholic University
Hsinchuang, New Taipei
City 242062, Taiwan, Republic of China
| | - Yu-Tung Tsai
- Department
of Chemistry, Fu-Jen Catholic University
Hsinchuang, New Taipei
City 242062, Taiwan, Republic of China
| | - Po-Ya Chang
- National
Synchrotron Radiation Research Center, Hsinchu 300092, Taiwan, Republic of China
| | - Mykhaylo Ozerov
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Jurek Krzystek
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Su-Ying Chien
- Instrumentation
Centre College of Science, National Taiwan
University, Taipei 10617, Taiwan,
Republic of China
| | - Jun-Xian He
- Department
of Chemistry, Fu-Jen Catholic University
Hsinchuang, New Taipei
City 242062, Taiwan, Republic of China
| | - Ting-Shen Kuo
- Centre
of National Taiwan Normal University, Taipei 11677, Taiwan, Republic of China
| | - Hwo-Shuenn Sheu
- National
Synchrotron Radiation Research Center, Hsinchu 300092, Taiwan, Republic of China
| |
Collapse
|
3
|
Kumar Sahu P, Kharel R, Shome S, Goswami S, Konar S. Understanding the unceasing evolution of Co(II) based single-ion magnets. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
4
|
Lou YS, Lin BR, Wu CM, Chien SY, Yang EC. Phonon-induced relaxation mechanisms are changed by a chelating effect in a Co II single-ion magnet. Dalton Trans 2022; 51:6646-6653. [PMID: 35403640 DOI: 10.1039/d1dt03515k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is well known that phonon-induced relaxation processes play a significant role in accelerating magnetization relaxation in the low-temperature regime. Unfortunately, many SIMs (single-ion magnets) suffer from being quenched by these mechanisms such that neither out-of-phase signals nor magnetization hysteresis can be readily observed. Nevertheless, because it involves molecular motions at low-frequency (low-energy) levels, methods for synthetically controlling this factor have not yet been addressed by chemists. In this study, we prepared a series of three compounds in which one contains a rigid chelating ligand, and the other two contain analogous ligands that can coordinate more liberally. To our surprise, compound 1, with a rigid chelating ligand, displayed promising SIM behavior with out-of-phase signals up to 11 K in a zero d.c. magnetic field at an a.c. frequency of 1000 Hz. The other two (2 and 3) with dangling ligands failed to show significant out-of-phase signals until an extra d.c. field was applied. The results of magnetization relaxation studies suggest that the phonon-induced relaxation processes play an essential role in 2 and 3, even at very low temperatures. Nevertheless, the rigid chelating ligand in 1 prevents the molecule from being involved in phonon-induced relaxation processes that seriously interfere with the magnetization relaxation up to 5.6 K. Therefore, we concluded that the presence of a rigid chelating ligand can efficiently change the phonon-induced relaxation processes at low temperatures.
Collapse
Affiliation(s)
- Yu-Siang Lou
- Department of Chemistry, Fu-Jen Catholic University, Hsinchuang, New Taipei City, 24205, Taiwan, Republic of China.
| | - Bo-Ruei Lin
- Department of Chemistry, Fu-Jen Catholic University, Hsinchuang, New Taipei City, 24205, Taiwan, Republic of China.
| | - Chen-Ming Wu
- Department of Chemistry, Fu-Jen Catholic University, Hsinchuang, New Taipei City, 24205, Taiwan, Republic of China.
| | - Su-Ying Chien
- Instrumentation Centre, College of Science, National Taiwan University, Taipei, 10672, Taiwan, Republic of China
| | - En-Che Yang
- Department of Chemistry, Fu-Jen Catholic University, Hsinchuang, New Taipei City, 24205, Taiwan, Republic of China.
| |
Collapse
|