TY - JOUR
T1 - Magnetic properties of conjugated phenoxy polyradicals
AU - Nishide, Hiroyuki
AU - Yoshioka, Naoki
AU - Tsuchida, Eishun
N1 - Funding Information:
This work was partially supported by a Grant-in-Aid for Scientific Research on the Priority Area of Macromolecular Complexes from the Ministry of Education, Science and Culture, Japan.
PY - 1990
Y1 - 1990
N2 - Formation and magnetic properties of π-conjugated phenoxy radicals bearing a porphyrin macrocycle or a polyacetylenic backbone are described. Tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)porphinatometals (7-M) [M = Zn(II), VO(II), and Cu(II)] were oxidized to give the corresponding stable monoradical and biradical. Magnetic properties of the radical species depend on the magnetic orbital of the central metal ion. ESR hfs structure reveals that the biradical for 7-Zn and - VO are in the triplet (S = 1) and quartet state (S = 3/2), respectively. Poly(3,5-di-t-butyl-4-hydroxyphenylacetylene) (8) and poly(p-ethynylphenylhydrogalvinoxyl) (9) with molecular weights of ~104 are characterized. ESR spectra with hyperfine structure for 8 indicate that the phenoxy radicals are conjugated with the polyacetylenic main chain over ~7 monomer units as a “neutral soliton.” Formed polyradicals for 8 and 9 are surprisingly stable, even in the solid state, due to resonance stabilization and/or steric effect of the conjugated main chain. An antiferromagnetic interaction is observed for oxidized 8 with a spin concentration above 10 mol%.
AB - Formation and magnetic properties of π-conjugated phenoxy radicals bearing a porphyrin macrocycle or a polyacetylenic backbone are described. Tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)porphinatometals (7-M) [M = Zn(II), VO(II), and Cu(II)] were oxidized to give the corresponding stable monoradical and biradical. Magnetic properties of the radical species depend on the magnetic orbital of the central metal ion. ESR hfs structure reveals that the biradical for 7-Zn and - VO are in the triplet (S = 1) and quartet state (S = 3/2), respectively. Poly(3,5-di-t-butyl-4-hydroxyphenylacetylene) (8) and poly(p-ethynylphenylhydrogalvinoxyl) (9) with molecular weights of ~104 are characterized. ESR spectra with hyperfine structure for 8 indicate that the phenoxy radicals are conjugated with the polyacetylenic main chain over ~7 monomer units as a “neutral soliton.” Formed polyradicals for 8 and 9 are surprisingly stable, even in the solid state, due to resonance stabilization and/or steric effect of the conjugated main chain. An antiferromagnetic interaction is observed for oxidized 8 with a spin concentration above 10 mol%.
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U2 - 10.1080/00222339009349690
DO - 10.1080/00222339009349690
M3 - Article
AN - SCOPUS:0025466369
VL - 27
SP - 1261
EP - 1273
JO - Journal of Macromolecular Science - Pure and Applied Chemistry
JF - Journal of Macromolecular Science - Pure and Applied Chemistry
SN - 1060-1325
IS - 9-11
ER -