Abstract
While the chemistry of open-shell singlet diradicaloids has been successfully developed in recent years, the synthesis of π-conjugated systems with poly-radical characters (i.e., beyond diradical) in the singlet ground state has been mostly unsuccessful. In this study, we report the synthesis and isolation of two fully fused macrocycles containing four (4MC) and six (6MC) alternatingly arranged quinoidal/aromatic carbazole units. Ab initio electronic structure calculations and various experimental measurements indicate that both 4MC and 6MC have an open-shell singlet ground state with moderate tetraradical and hexaradical characters, respectively. Both compounds can be thermally populated to high-spin excited states, resulting in weak magnetization at room temperature. Our study represents the first demonstration of singlet π-conjugated molecules with poly-radical characters and also gives some insights into molecular magnetism in neutral π-conjugated polycyclic heteroarenes.
| Original language | English |
|---|---|
| Pages (from-to) | 7782-7790 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 138 |
| Issue number | 24 |
| DOIs | |
| Publication status | Published - Jun 22 2016 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry
Cite this
Fully Fused Quinoidal/Aromatic Carbazole Macrocycles with Poly-radical Characters. / Das, Soumyajit; Herng, Tun Seng; Zafra, José L.; Burrezo, Paula Mayorga; Kitano, Masaaki; Ishida, Masatoshi; Gopalakrishna, Tullimilli Y.; Hu, Pan; Osuka, Atsuhiro; Casado, Juan; Ding, Jun; Casanova, David; Wu, Jishan.
In: Journal of the American Chemical Society, Vol. 138, No. 24, 22.06.2016, p. 7782-7790.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fully Fused Quinoidal/Aromatic Carbazole Macrocycles with Poly-radical Characters
AU - Das, Soumyajit
AU - Herng, Tun Seng
AU - Zafra, José L.
AU - Burrezo, Paula Mayorga
AU - Kitano, Masaaki
AU - Ishida, Masatoshi
AU - Gopalakrishna, Tullimilli Y.
AU - Hu, Pan
AU - Osuka, Atsuhiro
AU - Casado, Juan
AU - Ding, Jun
AU - Casanova, David
AU - Wu, Jishan
PY - 2016/6/22
Y1 - 2016/6/22
N2 - While the chemistry of open-shell singlet diradicaloids has been successfully developed in recent years, the synthesis of π-conjugated systems with poly-radical characters (i.e., beyond diradical) in the singlet ground state has been mostly unsuccessful. In this study, we report the synthesis and isolation of two fully fused macrocycles containing four (4MC) and six (6MC) alternatingly arranged quinoidal/aromatic carbazole units. Ab initio electronic structure calculations and various experimental measurements indicate that both 4MC and 6MC have an open-shell singlet ground state with moderate tetraradical and hexaradical characters, respectively. Both compounds can be thermally populated to high-spin excited states, resulting in weak magnetization at room temperature. Our study represents the first demonstration of singlet π-conjugated molecules with poly-radical characters and also gives some insights into molecular magnetism in neutral π-conjugated polycyclic heteroarenes.
AB - While the chemistry of open-shell singlet diradicaloids has been successfully developed in recent years, the synthesis of π-conjugated systems with poly-radical characters (i.e., beyond diradical) in the singlet ground state has been mostly unsuccessful. In this study, we report the synthesis and isolation of two fully fused macrocycles containing four (4MC) and six (6MC) alternatingly arranged quinoidal/aromatic carbazole units. Ab initio electronic structure calculations and various experimental measurements indicate that both 4MC and 6MC have an open-shell singlet ground state with moderate tetraradical and hexaradical characters, respectively. Both compounds can be thermally populated to high-spin excited states, resulting in weak magnetization at room temperature. Our study represents the first demonstration of singlet π-conjugated molecules with poly-radical characters and also gives some insights into molecular magnetism in neutral π-conjugated polycyclic heteroarenes.
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U2 - 10.1021/jacs.6b04539
DO - 10.1021/jacs.6b04539
M3 - Article
VL - 138
SP - 7782
EP - 7790
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 24
ER -