Persistent, highly localized, and tunable [4]helicene radicals

Aslam C. Shaikh; Jules Moutet; José M. Veleta; Md Mubarak Hossain; Jan Bloch; Andrei V. Astashkin; Thomas L. Gianetti

doi:10.1039/d0sc04850j

Persistent, highly localized, and tunable [4]helicene radicals

Aslam C. Shaikh, Jules Moutet, José M. Veleta, Md Mubarak Hossain, Jan Bloch, Andrei V. Astashkin, Thomas L. Gianetti

Chemistry and Biochemistry

Research output: Contribution to journal › Article › peer-review

22 Scopus citations

Abstract

Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs. The structures of these [4]helicene radicals were determined by X-ray crystallography. Density functional theory (DFT) calculations, supported by electron paramagnetic resonance (EPR) measurements, indicate that over 40% of spin density is located at the central carbon of our [4]helicene radicals regardless of their structural modifications. The localization of the charge promotes a reversible oxidation to the cation upon exposure to air. This unusual reactivity toward molecular oxygen was monitored via UV-Vis spectroscopy.

Original language	English (US)
Pages (from-to)	11060-11067
Number of pages	8
Journal	Chemical Science
Volume	11
Issue number	40
DOIs	https://doi.org/10.1039/d0sc04850j
State	Published - Oct 28 2020

ASJC Scopus subject areas

General Chemistry

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10.1039/d0sc04850j

Cite this

@article{8b02817846b942aba75e4c0eaadfe95b,

title = "Persistent, highly localized, and tunable [4]helicene radicals",

abstract = "Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs. The structures of these [4]helicene radicals were determined by X-ray crystallography. Density functional theory (DFT) calculations, supported by electron paramagnetic resonance (EPR) measurements, indicate that over 40% of spin density is located at the central carbon of our [4]helicene radicals regardless of their structural modifications. The localization of the charge promotes a reversible oxidation to the cation upon exposure to air. This unusual reactivity toward molecular oxygen was monitored via UV-Vis spectroscopy.",

author = "Shaikh, {Aslam C.} and Jules Moutet and Veleta, {Jos{\'e} M.} and Hossain, {Md Mubarak} and Jan Bloch and Astashkin, {Andrei V.} and Gianetti, {Thomas L.}",

note = "Funding Information: We are grateful for nancial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Funding Information: We are grateful for financial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Publisher Copyright: {\textcopyright} The Royal Society of Chemistry.",

year = "2020",

month = oct,

day = "28",

doi = "10.1039/d0sc04850j",

language = "English (US)",

volume = "11",

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journal = "Chemical Science",

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publisher = "Royal Society of Chemistry",

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T1 - Persistent, highly localized, and tunable [4]helicene radicals

AU - Shaikh, Aslam C.

AU - Moutet, Jules

AU - Veleta, José M.

AU - Hossain, Md Mubarak

AU - Bloch, Jan

AU - Astashkin, Andrei V.

AU - Gianetti, Thomas L.

N1 - Funding Information: We are grateful for nancial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Funding Information: We are grateful for financial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Publisher Copyright: © The Royal Society of Chemistry.

PY - 2020/10/28

Y1 - 2020/10/28

N2 - Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs. The structures of these [4]helicene radicals were determined by X-ray crystallography. Density functional theory (DFT) calculations, supported by electron paramagnetic resonance (EPR) measurements, indicate that over 40% of spin density is located at the central carbon of our [4]helicene radicals regardless of their structural modifications. The localization of the charge promotes a reversible oxidation to the cation upon exposure to air. This unusual reactivity toward molecular oxygen was monitored via UV-Vis spectroscopy.

AB - Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs. The structures of these [4]helicene radicals were determined by X-ray crystallography. Density functional theory (DFT) calculations, supported by electron paramagnetic resonance (EPR) measurements, indicate that over 40% of spin density is located at the central carbon of our [4]helicene radicals regardless of their structural modifications. The localization of the charge promotes a reversible oxidation to the cation upon exposure to air. This unusual reactivity toward molecular oxygen was monitored via UV-Vis spectroscopy.

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DO - 10.1039/d0sc04850j

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VL - 11

SP - 11060

EP - 11067

JO - Chemical Science

JF - Chemical Science

IS - 40

ER -

Persistent, highly localized, and tunable [4]helicene radicals

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CCDC 2004975: Experimental Crystal Structure Determination

CCDC 2004976: Experimental Crystal Structure Determination

CCDC 2004974: Experimental Crystal Structure Determination

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Persistent, highly localized, and tunable [4]helicene radicals

Abstract

ASJC Scopus subject areas

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CCDC 2004975: Experimental Crystal Structure Determination

CCDC 2004976: Experimental Crystal Structure Determination

CCDC 2004974: Experimental Crystal Structure Determination

Cite this