Benzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity

Handle URI:
http://hdl.handle.net/10754/594724
Title:
Benzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity
Authors:
Shi, Xueliang; Quintero, EstefanÍa; Lee, Sangsu; Jing, Linzhi; Herng, Tun Seng; Zheng, Bin; Huang, Kuo-Wei ( 0000-0003-1900-2658 ) ; López Navarrete, Juan T.; Ding, Jun; Kim, Dongho; Casado, Juan; Chi, Chunyan
Abstract:
Open-shell singlet diradicaloids recently have received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing designs. However, there still lacks fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties. In this work, a series of pro-aromatic benzo-thia-fused [n]thienoacenequinodimethanes (Thn-TIPS (n=1-3) and BDTh-TIPS) were synthesized and compared with the previously reported anti-aromatic bisindeno-[n]thienoacenes (Sn-TIPS, n=1-4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (y0) increased from nearly zero for Th1-TIPS to 2.4% for Th2-TIPS, 18.2% for Th3-TIPS, and 38.2% for BDTh-TIPS, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues Sn-TIPS (n=1-3), the pro-aromatic Thn-TIPS (n=1-3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work disclosed the significant difference between the pro-aromatic and anti-aromatic quinoidal compounds and provided guidance for the design of new diradicaloids with desirable properties.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)
Citation:
Benzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity 2016 Chem. Sci.
Publisher:
Royal Society of Chemistry (RSC)
Journal:
Chem. Sci.
Issue Date:
19-Jan-2016
DOI:
10.1039/C5SC04706D
Type:
Article
ISSN:
2041-6520; 2041-6539
Is Supplemented By:
Shi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419444: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1jr; DOI:10.5517/cc1jn1jr; HANDLE:http://hdl.handle.net/10754/624463; Shi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419445: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1ks; DOI:10.5517/cc1jn1ks; HANDLE:http://hdl.handle.net/10754/624464; Shi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419446: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1lt; DOI:10.5517/cc1jn1lt; HANDLE:http://hdl.handle.net/10754/624465; Shi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419447: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1mv; DOI:10.5517/cc1jn1mv; HANDLE:http://hdl.handle.net/10754/624466
Additional Links:
http://pubs.rsc.org/en/Content/ArticleLanding/2016/SC/C5SC04706D
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorShi, Xueliangen
dc.contributor.authorQuintero, EstefanÍaen
dc.contributor.authorLee, Sangsuen
dc.contributor.authorJing, Linzhien
dc.contributor.authorHerng, Tun Sengen
dc.contributor.authorZheng, Binen
dc.contributor.authorHuang, Kuo-Weien
dc.contributor.authorLópez Navarrete, Juan T.en
dc.contributor.authorDing, Junen
dc.contributor.authorKim, Donghoen
dc.contributor.authorCasado, Juanen
dc.contributor.authorChi, Chunyanen
dc.date.accessioned2016-01-24T10:21:38Zen
dc.date.available2016-01-24T10:21:38Zen
dc.date.issued2016-01-19en
dc.identifier.citationBenzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity 2016 Chem. Sci.en
dc.identifier.issn2041-6520en
dc.identifier.issn2041-6539en
dc.identifier.doi10.1039/C5SC04706Den
dc.identifier.urihttp://hdl.handle.net/10754/594724en
dc.description.abstractOpen-shell singlet diradicaloids recently have received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing designs. However, there still lacks fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties. In this work, a series of pro-aromatic benzo-thia-fused [n]thienoacenequinodimethanes (Thn-TIPS (n=1-3) and BDTh-TIPS) were synthesized and compared with the previously reported anti-aromatic bisindeno-[n]thienoacenes (Sn-TIPS, n=1-4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (y0) increased from nearly zero for Th1-TIPS to 2.4% for Th2-TIPS, 18.2% for Th3-TIPS, and 38.2% for BDTh-TIPS, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues Sn-TIPS (n=1-3), the pro-aromatic Thn-TIPS (n=1-3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work disclosed the significant difference between the pro-aromatic and anti-aromatic quinoidal compounds and provided guidance for the design of new diradicaloids with desirable properties.en
dc.language.isoenen
dc.publisherRoyal Society of Chemistry (RSC)en
dc.relation.urlhttp://pubs.rsc.org/en/Content/ArticleLanding/2016/SC/C5SC04706Den
dc.rightsThis article is licensed under a Creative Commons Attribution 3.0 Unported Licence.http://creativecommons.org/licenses/by/3.0/en
dc.titleBenzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticityen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.identifier.journalChem. Sci.en
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singaporeen
dc.contributor.institutionDepartment of Physical Chemistry, University of Malaga, Campus de Teatinos s/n, 229071 Malaga, Spainen
dc.contributor.institutionDepartment of Chemistry, Yonsei University, Seoul 120-749, Koreaen
dc.contributor.institutionDepartment of Materials Science & Engineering, National University of Singapore, 119260, Singaporeen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorZheng, Binen
kaust.authorHuang, Kuo-Weien
dc.relation.isSupplementedByShi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419444: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1jren
dc.relation.isSupplementedByDOI:10.5517/cc1jn1jren
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624463en
dc.relation.isSupplementedByShi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419445: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1ksen
dc.relation.isSupplementedByDOI:10.5517/cc1jn1ksen
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624464en
dc.relation.isSupplementedByShi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419446: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1lten
dc.relation.isSupplementedByDOI:10.5517/cc1jn1lten
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624465en
dc.relation.isSupplementedByShi, X., Quintero, E., Lee, S., Jing, L., Herng, T. S., Zheng, B., … Chi, C. (2015). CCDC 1419447: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc1jn1mven
dc.relation.isSupplementedByDOI:10.5517/cc1jn1mven
dc.relation.isSupplementedByHANDLE:http://hdl.handle.net/10754/624466en
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