Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks
Two new cobalt(II) complexes with an unsymmetrical bidentate ligand, 2-(1,4,5,6-tetrahydropyrimidin-2-yl)-6-methoxyphenol (H<sub>2</sub>mthp), were synthesized and crystallographically characterized. Tetra- and hexa-coordinate mononuclear complexes were selectively obtained by adjusting...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-01-01
|
| Series: | Magnetochemistry |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2312-7481/9/1/17 |
| _version_ | 1797439405816807424 |
|---|---|
| author | Ryoji Mitsuhashi Hiroshi Sakiyama Yoshihito Hayashi |
| author_facet | Ryoji Mitsuhashi Hiroshi Sakiyama Yoshihito Hayashi |
| author_sort | Ryoji Mitsuhashi |
| collection | DOAJ |
| description | Two new cobalt(II) complexes with an unsymmetrical bidentate ligand, 2-(1,4,5,6-tetrahydropyrimidin-2-yl)-6-methoxyphenol (H<sub>2</sub>mthp), were synthesized and crystallographically characterized. Tetra- and hexa-coordinate mononuclear complexes were selectively obtained by adjusting the stoichiometry of the base. The coordination geometry of hexa-coordinated complex was severely distorted from an ideal octahedron, due to the NO<sub>5</sub> coordination environment from the mixed coordination of one Hmthp<sup>−</sup> and two H<sub>2</sub>mthp ligands. Both complexes formed one-dimensional chain networks by hydrogen-bond and N-H···π interactions. Single-molecule magnet behavior was observed for the tetrahedral complex under zero magnetic field. The relatively short Co···Co distances induced non-zero intermolecular magnetic coupling, which split the ground ±<i>M<sub>s</sub></i> levels to suppress quantum-tunneling of magnetization. In the octahedral complex, by contrast, the distance was not short enough to induce the coupling. As a consequence, single-molecule magnetic behavior was observed for the octahedral complex only in the presence of an external static field. |
| first_indexed | 2024-03-09T11:52:26Z |
| format | Article |
| id | doaj.art-6508c32a005640b596f7c657b911ee86 |
| institution | Directory Open Access Journal |
| issn | 2312-7481 |
| language | English |
| last_indexed | 2024-03-09T11:52:26Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Magnetochemistry |
| spelling | doaj.art-6508c32a005640b596f7c657b911ee862023-11-30T23:12:51ZengMDPI AGMagnetochemistry2312-74812023-01-01911710.3390/magnetochemistry9010017Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded NetworksRyoji Mitsuhashi0Hiroshi Sakiyama1Yoshihito Hayashi2Institute of Liberal Arts and Science, Kanazawa University, Kakuma, Kanazawa 920-1192, JapanDepartment of Science, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, JapanDepartment of Chemistry, Kanazawa University, Kakuma, Kanazawa 920-1192, JapanTwo new cobalt(II) complexes with an unsymmetrical bidentate ligand, 2-(1,4,5,6-tetrahydropyrimidin-2-yl)-6-methoxyphenol (H<sub>2</sub>mthp), were synthesized and crystallographically characterized. Tetra- and hexa-coordinate mononuclear complexes were selectively obtained by adjusting the stoichiometry of the base. The coordination geometry of hexa-coordinated complex was severely distorted from an ideal octahedron, due to the NO<sub>5</sub> coordination environment from the mixed coordination of one Hmthp<sup>−</sup> and two H<sub>2</sub>mthp ligands. Both complexes formed one-dimensional chain networks by hydrogen-bond and N-H···π interactions. Single-molecule magnet behavior was observed for the tetrahedral complex under zero magnetic field. The relatively short Co···Co distances induced non-zero intermolecular magnetic coupling, which split the ground ±<i>M<sub>s</sub></i> levels to suppress quantum-tunneling of magnetization. In the octahedral complex, by contrast, the distance was not short enough to induce the coupling. As a consequence, single-molecule magnetic behavior was observed for the octahedral complex only in the presence of an external static field.https://www.mdpi.com/2312-7481/9/1/17cobalt(II) complexhydrogen-bonding interactionssingle-ion magnet |
| spellingShingle | Ryoji Mitsuhashi Hiroshi Sakiyama Yoshihito Hayashi Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks Magnetochemistry cobalt(II) complex hydrogen-bonding interactions single-ion magnet |
| title | Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks |
| title_full | Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks |
| title_fullStr | Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks |
| title_full_unstemmed | Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks |
| title_short | Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks |
| title_sort | slow magnetic relaxation in cobalt ii complexes with one dimensional hydrogen bonded networks |
| topic | cobalt(II) complex hydrogen-bonding interactions single-ion magnet |
| url | https://www.mdpi.com/2312-7481/9/1/17 |
| work_keys_str_mv | AT ryojimitsuhashi slowmagneticrelaxationincobaltiicomplexeswithonedimensionalhydrogenbondednetworks AT hiroshisakiyama slowmagneticrelaxationincobaltiicomplexeswithonedimensionalhydrogenbondednetworks AT yoshihitohayashi slowmagneticrelaxationincobaltiicomplexeswithonedimensionalhydrogenbondednetworks |