Kinetically blocked stable heptazethrene and octazethrene: Closed-shell or open-shell in the ground state?

Handle URI:
http://hdl.handle.net/10754/562326
Title:
Kinetically blocked stable heptazethrene and octazethrene: Closed-shell or open-shell in the ground state?
Authors:
Li, Yuan; Heng, WeeKuan; Lee, Byungsun; Aratani, Naoki; Zafra, José Luis; Bao, Nina; Lee, Richmond; Sung, Youngmo; Sun, Zhe; Huang, Kuo-Wei ( 0000-0003-1900-2658 ) ; Webster, Richard D.; Lõpez Navarrete, Juan Teodomiro; Kim, Dongho; Osuka, Atsuhiro; Casado, Juan; Ding, Jun; Wu, Jishan
Abstract:
Polycyclic aromatic hydrocarbons with an open-shell singlet biradical ground state are of fundamental interest and have potential applications in materials science. However, the inherent high reactivity makes their synthesis and characterization very challenging. In this work, a convenient synthetic route was developed to synthesize two kinetically blocked heptazethrene (HZ-TIPS) and octazethrene (OZ-TIPS) compounds with good stability. Their ground-state electronic structures were systematically investigated by a combination of different experimental methods, including steady-state and transient absorption spectroscopy, variable temperature NMR, electron spin resonance (ESR), superconducting quantum interfering device (SQUID), FT Raman, and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. All these demonstrated that the heptazethrene derivative HZ-TIPS has a closed-shell ground state while its octazethrene analogue OZ-TIPS with a smaller energy gap exists as an open-shell singlet biradical with a large measured biradical character (y = 0.56). Large two-photon absorption (TPA) cross sections (σ(2)) were determined for HZ-TIPS (σ(2)max = 920 GM at 1250 nm) and OZ-TIPS (σ(2)max = 1200 GM at 1250 nm). In addition, HZ-TIPS and OZ-TIPS show a closely stacked 1D polymer chain in single crystals. © 2012 American Chemical Society.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; KAUST Catalysis Center (KCC); Chemical Science Program; Physical Sciences and Engineering (PSE) Division; HCL
Publisher:
American Chemical Society (ACS)
Journal:
Journal of the American Chemical Society
Issue Date:
12-Sep-2012
DOI:
10.1021/ja304618v
PubMed ID:
22908899
Type:
Article
ISSN:
00027863
Sponsors:
J.W. acknowledges the financial support from the BMRC-NMRC grant (no. 10/1/21/19/642), MOE Tier 2 grant (MOE2011-T2-2-130), and A*STAR IMRE core funding (IMRE/10-1P0509). The work at Yonsei University was supported by WCU (World Class University) programs (R32-2010-10217-0) and an AFSOR/APARD grant (no. FA2386-09-1-4092). K.-W.H. acknowledges the financial support from KAUST. We thank Ji'En Wu and Yanhui Han for their kind assistance on the NMR analysis and Prof. Yuan-Chung Cheng for useful discussion.
Is Supplemented By:
Li, Y., Heng, W.-K., Lee, B. S., Aratani, N., Zafra, J. L., Bao, N., … Wu, J. (2013). CCDC 875408: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/ccycxz5; DOI:10.5517/ccycxz5; HANDLE:http://hdl.handle.net/10754/624689; Li, Y., Heng, W.-K., Lee, B. S., Aratani, N., Zafra, J. L., Bao, N., … Wu, J. (2013). CCDC 875409: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/ccycy07; DOI:10.5517/ccycy07; HANDLE:http://hdl.handle.net/10754/624690
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorLi, Yuanen
dc.contributor.authorHeng, WeeKuanen
dc.contributor.authorLee, Byungsunen
dc.contributor.authorAratani, Naokien
dc.contributor.authorZafra, José Luisen
dc.contributor.authorBao, Ninaen
dc.contributor.authorLee, Richmonden
dc.contributor.authorSung, Youngmoen
dc.contributor.authorSun, Zheen
dc.contributor.authorHuang, Kuo-Weien
dc.contributor.authorWebster, Richard D.en
dc.contributor.authorLõpez Navarrete, Juan Teodomiroen
dc.contributor.authorKim, Donghoen
dc.contributor.authorOsuka, Atsuhiroen
dc.contributor.authorCasado, Juanen
dc.contributor.authorDing, Junen
dc.contributor.authorWu, Jishanen
dc.date.accessioned2015-08-03T10:01:01Zen
dc.date.available2015-08-03T10:01:01Zen
dc.date.issued2012-09-12en
dc.identifier.issn00027863en
dc.identifier.pmid22908899en
dc.identifier.doi10.1021/ja304618ven
dc.identifier.urihttp://hdl.handle.net/10754/562326en
dc.description.abstractPolycyclic aromatic hydrocarbons with an open-shell singlet biradical ground state are of fundamental interest and have potential applications in materials science. However, the inherent high reactivity makes their synthesis and characterization very challenging. In this work, a convenient synthetic route was developed to synthesize two kinetically blocked heptazethrene (HZ-TIPS) and octazethrene (OZ-TIPS) compounds with good stability. Their ground-state electronic structures were systematically investigated by a combination of different experimental methods, including steady-state and transient absorption spectroscopy, variable temperature NMR, electron spin resonance (ESR), superconducting quantum interfering device (SQUID), FT Raman, and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. All these demonstrated that the heptazethrene derivative HZ-TIPS has a closed-shell ground state while its octazethrene analogue OZ-TIPS with a smaller energy gap exists as an open-shell singlet biradical with a large measured biradical character (y = 0.56). Large two-photon absorption (TPA) cross sections (σ(2)) were determined for HZ-TIPS (σ(2)max = 920 GM at 1250 nm) and OZ-TIPS (σ(2)max = 1200 GM at 1250 nm). In addition, HZ-TIPS and OZ-TIPS show a closely stacked 1D polymer chain in single crystals. © 2012 American Chemical Society.en
dc.description.sponsorshipJ.W. acknowledges the financial support from the BMRC-NMRC grant (no. 10/1/21/19/642), MOE Tier 2 grant (MOE2011-T2-2-130), and A*STAR IMRE core funding (IMRE/10-1P0509). The work at Yonsei University was supported by WCU (World Class University) programs (R32-2010-10217-0) and an AFSOR/APARD grant (no. FA2386-09-1-4092). K.-W.H. acknowledges the financial support from KAUST. We thank Ji'En Wu and Yanhui Han for their kind assistance on the NMR analysis and Prof. Yuan-Chung Cheng for useful discussion.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleKinetically blocked stable heptazethrene and octazethrene: Closed-shell or open-shell in the ground state?en
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentHCLen
dc.identifier.journalJournal of the American Chemical Societyen
dc.contributor.institutionDepartment of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singaporeen
dc.contributor.institutionSpectroscopy Laboratory for Functional - Electronic Systems, Department of Chemistry, Yonsei University, Seoul 120-749, South Koreaen
dc.contributor.institutionDepartment of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japanen
dc.contributor.institutionDepartment of Physical Chemistry, University of Malaga, Campus de Teatinos s/n, 229071 Malaga, Spainen
dc.contributor.institutionDepartment of Materials Science and Engineering, National University of Singapore, 119260, Singapore, Singaporeen
dc.contributor.institutionDivision of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore, Singaporeen
dc.contributor.institutionInstitute of Materials Research and Engineering, AStar, 3 Research Link, Singapore, 117602, Singaporeen
kaust.authorLee, Richmonden
kaust.authorHuang, Kuo-Weien
dc.relation.isSupplementedByLi, Y., Heng, W.-K., Lee, B. S., Aratani, N., Zafra, J. L., Bao, N., … Wu, J. (2013). CCDC 875408: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/ccycxz5en
dc.relation.isSupplementedByDOI:10.5517/ccycxz5en
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624689en
dc.relation.isSupplementedByLi, Y., Heng, W.-K., Lee, B. S., Aratani, N., Zafra, J. L., Bao, N., … Wu, J. (2013). CCDC 875409: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/ccycy07en
dc.relation.isSupplementedByDOI:10.5517/ccycy07en
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624690en

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