Abstract
A reaction of Cu(II) nitrate and 4,4,5,5-tetramethyl-2-(2-hydroxophenyl) imidazolin-1-oxyl (IM2PhOH) with potassium methoxide in methanol gave a homoleptic bis(imino nitroxide) complex of [Cu(IM2PhO)2] (1). The single-crystal X-ray analysis of 1 showed that the imino nitroxide anion, IM2PhO-, chelated to a CuII ion via an imino-N and a phenoxide-O atoms to form a six-membered chelate ring. The coordination geometry around the Cu(II) ion was a distorted square-planar polygon; the dihedral angle between the two coordination planes, each of which was defined by Cu and two ligating atoms of IM2PhO-, was 40.81°. The temperature dependences of the magnetic susceptibility and the EPR spectra of 1 indicate that the magnetic interaction between Cu(II) and the imino nitroxide is ferromagnetic, while there is a moderate antiferromagnetic interaction between two coordinated imino nitroxides. A balance between these opposite interactions attains the lowest molecular doublet spin-state in 1. The variable temperature magnetic circular dichroism (MCD) spectrum of the complex 1 also showed two negative components with a large C term, which may be due to the charge-transfer (CT) transition originated from the d orbital to the SOMO π* orbital in the spin-coupled IM2PhO- radicals; resulting in the largely split doublet excited states with the spin singlet and triplet d8 configurations.
| Original language | English |
|---|---|
| Pages (from-to) | 3125-3133 |
| Number of pages | 9 |
| Journal | Inorganica Chimica Acta |
| Volume | 357 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Aug 5 2004 |
| Externally published | Yes |
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Keywords
- Cu(II) complex
- EPR
- Imino nitroxide radical
- Magnetic interaction
- MCD
ASJC Scopus subject areas
- Biochemistry
- Inorganic Chemistry
- Physical and Theoretical Chemistry
- Materials Chemistry
Cite this
Synthesis, magnetic properties and MCD spectra of a four coordinate copper(II) complex with two chelated phenolate-substituted imino nitroxides. / Kanda, Hironori; Narumi, Yasuo; Hosokoshi, Yuko; Suzuki, Takayoshi; Kawata, Satoshi; Kindo, Koichi; Inoue, Katsuya; Kaizaki, Sumio.
In: Inorganica Chimica Acta, Vol. 357, No. 11, 05.08.2004, p. 3125-3133.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis, magnetic properties and MCD spectra of a four coordinate copper(II) complex with two chelated phenolate-substituted imino nitroxides
AU - Kanda, Hironori
AU - Narumi, Yasuo
AU - Hosokoshi, Yuko
AU - Suzuki, Takayoshi
AU - Kawata, Satoshi
AU - Kindo, Koichi
AU - Inoue, Katsuya
AU - Kaizaki, Sumio
PY - 2004/8/5
Y1 - 2004/8/5
N2 - A reaction of Cu(II) nitrate and 4,4,5,5-tetramethyl-2-(2-hydroxophenyl) imidazolin-1-oxyl (IM2PhOH) with potassium methoxide in methanol gave a homoleptic bis(imino nitroxide) complex of [Cu(IM2PhO)2] (1). The single-crystal X-ray analysis of 1 showed that the imino nitroxide anion, IM2PhO-, chelated to a CuII ion via an imino-N and a phenoxide-O atoms to form a six-membered chelate ring. The coordination geometry around the Cu(II) ion was a distorted square-planar polygon; the dihedral angle between the two coordination planes, each of which was defined by Cu and two ligating atoms of IM2PhO-, was 40.81°. The temperature dependences of the magnetic susceptibility and the EPR spectra of 1 indicate that the magnetic interaction between Cu(II) and the imino nitroxide is ferromagnetic, while there is a moderate antiferromagnetic interaction between two coordinated imino nitroxides. A balance between these opposite interactions attains the lowest molecular doublet spin-state in 1. The variable temperature magnetic circular dichroism (MCD) spectrum of the complex 1 also showed two negative components with a large C term, which may be due to the charge-transfer (CT) transition originated from the d orbital to the SOMO π* orbital in the spin-coupled IM2PhO- radicals; resulting in the largely split doublet excited states with the spin singlet and triplet d8 configurations.
AB - A reaction of Cu(II) nitrate and 4,4,5,5-tetramethyl-2-(2-hydroxophenyl) imidazolin-1-oxyl (IM2PhOH) with potassium methoxide in methanol gave a homoleptic bis(imino nitroxide) complex of [Cu(IM2PhO)2] (1). The single-crystal X-ray analysis of 1 showed that the imino nitroxide anion, IM2PhO-, chelated to a CuII ion via an imino-N and a phenoxide-O atoms to form a six-membered chelate ring. The coordination geometry around the Cu(II) ion was a distorted square-planar polygon; the dihedral angle between the two coordination planes, each of which was defined by Cu and two ligating atoms of IM2PhO-, was 40.81°. The temperature dependences of the magnetic susceptibility and the EPR spectra of 1 indicate that the magnetic interaction between Cu(II) and the imino nitroxide is ferromagnetic, while there is a moderate antiferromagnetic interaction between two coordinated imino nitroxides. A balance between these opposite interactions attains the lowest molecular doublet spin-state in 1. The variable temperature magnetic circular dichroism (MCD) spectrum of the complex 1 also showed two negative components with a large C term, which may be due to the charge-transfer (CT) transition originated from the d orbital to the SOMO π* orbital in the spin-coupled IM2PhO- radicals; resulting in the largely split doublet excited states with the spin singlet and triplet d8 configurations.
KW - Cu(II) complex
KW - EPR
KW - Imino nitroxide radical
KW - Magnetic interaction
KW - MCD
UR - http://www.scopus.com/inward/record.url?scp=3242778658&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=3242778658&partnerID=8YFLogxK
U2 - 10.1016/j.ica.2004.03.017
DO - 10.1016/j.ica.2004.03.017
M3 - Article
AN - SCOPUS:3242778658
VL - 357
SP - 3125
EP - 3133
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
SN - 0020-1693
IS - 11
ER -