Details
| Original language | English |
|---|---|
| Pages (from-to) | 5658-5662 |
| Number of pages | 5 |
| Journal | Angewandte Chemie |
| Volume | 58 |
| Issue number | 17 |
| Early online date | 12 Feb 2019 |
| Publication status | Published - 9 Apr 2019 |
Abstract
A mononuclear Fe II complex, prepared with a Brønsted diacid ligand, H 2 L (H 2 L=2-[5-phenyl-1H-pyrazole-3-yl] 6-benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [Fe II (H 2 L) 2 ](BF 4 ) 2 (1 A ), exhibits abrupt spin transition at T 1/2 =258 K, and treatment with base yields a deprotonated analogue [Fe II (HL) 2 ] (1 B ), which shows gradual SCO above 350 K. A range of Fe III analogues were also characterized. [Fe III (HL)(H 2 L)](BF 4 )Cl (1 C ) has an S=5/2 spin state, while the deprotonated complexes [Fe III (L)(HL)], (1 D ), and (TEA)[Fe III (L) 2 ], (1 E ) exist in the low-spin S=1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid-state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices.
Keywords
- Brønsted acid/base, iron, magnetism, molecular switch, spin crossover
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Chemistry(all)
- General Chemistry
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In: Angewandte Chemie , Vol. 58, No. 17, 09.04.2019, p. 5658-5662.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - A Brønsted-Ligand-Based Iron Complex as a Molecular Switch with Five Accessible States
AU - Shiga, Takuya
AU - Saiki, Ryo
AU - Akiyama, Lisa
AU - Kumai, Reiji
AU - Natke, Dominik
AU - Renz, Franz
AU - Cameron, Jamie M.
AU - Newton, Graham N.
AU - Oshio, Hiroki
N1 - Funding information: This work was supported by a Grant-in-Aid for Challenging Exploratory Research (no. 18K19088), Grant-in-Aid for Scientific Research (C) (no. 17K05800) and Grant-in-Aid for Scientific Research on Innovative Areas “Coordination Asymmetry” (no. JP16H06523) from the Japan Society for the Promotion of Science (JSPS). This work was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2018G102). We thank the University of Nottingham Propulsion Futures Beacon and the Leverhulme Trust (RPG-2016-442) for funding towards this research.
PY - 2019/4/9
Y1 - 2019/4/9
N2 - A mononuclear Fe II complex, prepared with a Brønsted diacid ligand, H 2 L (H 2 L=2-[5-phenyl-1H-pyrazole-3-yl] 6-benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [Fe II (H 2 L) 2 ](BF 4 ) 2 (1 A ), exhibits abrupt spin transition at T 1/2 =258 K, and treatment with base yields a deprotonated analogue [Fe II (HL) 2 ] (1 B ), which shows gradual SCO above 350 K. A range of Fe III analogues were also characterized. [Fe III (HL)(H 2 L)](BF 4 )Cl (1 C ) has an S=5/2 spin state, while the deprotonated complexes [Fe III (L)(HL)], (1 D ), and (TEA)[Fe III (L) 2 ], (1 E ) exist in the low-spin S=1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid-state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices.
AB - A mononuclear Fe II complex, prepared with a Brønsted diacid ligand, H 2 L (H 2 L=2-[5-phenyl-1H-pyrazole-3-yl] 6-benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [Fe II (H 2 L) 2 ](BF 4 ) 2 (1 A ), exhibits abrupt spin transition at T 1/2 =258 K, and treatment with base yields a deprotonated analogue [Fe II (HL) 2 ] (1 B ), which shows gradual SCO above 350 K. A range of Fe III analogues were also characterized. [Fe III (HL)(H 2 L)](BF 4 )Cl (1 C ) has an S=5/2 spin state, while the deprotonated complexes [Fe III (L)(HL)], (1 D ), and (TEA)[Fe III (L) 2 ], (1 E ) exist in the low-spin S=1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid-state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices.
KW - Brønsted acid/base
KW - iron
KW - magnetism
KW - molecular switch
KW - spin crossover
UR - http://www.scopus.com/inward/record.url?scp=85064046771&partnerID=8YFLogxK
U2 - 10.1002/anie.201900909
DO - 10.1002/anie.201900909
M3 - Article
C2 - 30753754
AN - SCOPUS:85064046771
VL - 58
SP - 5658
EP - 5662
JO - Angewandte Chemie
JF - Angewandte Chemie
SN - 1433-7851
IS - 17
ER -