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Thiophene and its sulfur inhibit indenoindenodibenzothiophene diradicals from low-energy lying thermal triplets

Abstract

Many qualitative structure–property correlations between diradical character and emerging molecular properties are known. For example, the increase of diradical character further decreases the singlet–triplet energy gap. Here we show that inclusion of thiophenes within a quinoidal polycyclic hydrocarbon imparts appreciable diradical character yet retains the large singlet–triplet energy gap, a phenomenon that has no precedent in the literature. The low aromatic character of thiophene and its electron-rich nature are the key properties leading to these unique findings. A new indenoindenodibenzothiophene scaffold has been prepared and fully characterized by several spectroscopies, magnetic measurements, solid-state X-ray and state-of-the-art quantum chemical calculations, all corroborating this unique dichotomy between the diradical input and the emerging magnetic properties. New structure–property relationships such as these are not only extremely important in the field of diradical chemistry and organic electronics, but also provide new insights into the versatility of π-electron chemical bonding.

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Fig. 1: PAHs with open-shell character.
Fig. 2: Theoretical assessment of IIDBT.
Fig. 3: Synthesis of IIDBT and trapping as the dihydro/dideuterio adducts 10cH2/10cD2.
Fig. 4: SQUID magnetic, solid-state and optoelectronic properties of IIDBT.

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Data availability

Crystallographic data for the structure reported in this Article have been deposited at the Cambridge Crystallographic Data Centre, under deposition no. CCDC 1832752 (10a). Copies of the data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif. All other data supporting the findings of this study are available within the Article and its Supplementary Information, or from the corresponding author upon reasonable request.

References

  1. Tschitschibabin, A. E. Über einige phenylierte Derivate des p,p-Ditolyls. Chem. Ber. 40, 1810–1819 (1907).

    Article  CAS  Google Scholar 

  2. Gopalakrishna, T. Y., Zeng, W., Lu, X. & Wu, J. From open-shell singlet diradicaloids to polyradicaloids. Chem. Commun. 54, 2186–2199 (2018).

    Article  Google Scholar 

  3. Di Motta, S., Negri, F., Fazzi, D., Castiglioni, C. & Canesi, E. V. Biradicaloid and polyenic character of quinoidal oligothiophenes revealed by the presence of a low-lying double-exciton state. J. Phys. Chem. Lett. 1, 3334–3339 (2010).

    Article  CAS  Google Scholar 

  4. Rudebusch, G. E. et al. Diindeno-fusion of an anthracene as a design strategy for stable organic biradicals. Nat. Chem. 8, 753–759 (2016).

    Article  CAS  Google Scholar 

  5. Morita, Y., Suzuki, S., Sato, K. & Takui, T. Synthetic organic spin chemistry for structurally well-defined open-shell graphene fragments. Nat. Chem. 3, 197–204 (2011).

    Article  CAS  PubMed  Google Scholar 

  6. Morita, Y. et al. Organic tailored batteries materials using stable open-shell molecules with degenerate frontier orbitals. Nat. Mater. 10, 947–951 (2011).

    Article  CAS  PubMed  Google Scholar 

  7. Nakano, M. et al. Second hyperpolarizability (γ) of singlet diradical system: dependence of γ on the diradical character. J. Phys. Chem. A 109, 885–891 (2005).

    Article  CAS  PubMed  Google Scholar 

  8. Nakano, M. et al. Relationship between third-order nonlinear optical properties and magnetic interactions in open-shell systems: a new paradigm for nonlinear optics. Phys. Rev. Lett. 99, 033001 (2007).

    Article  CAS  PubMed  Google Scholar 

  9. Nakano, M. & Champagne, B. Theoretical design of open-shell singlet molecular systems for nonlinear optics. J. Phys. Chem. Lett. 6, 3236–3256 (2015).

    Article  CAS  Google Scholar 

  10. Minami, T. & Nakano, M. Diradical character view of singlet fission. J. Phys. Chem. Lett. 3, 145–150 (2012).

    Article  CAS  Google Scholar 

  11. Smith, M. B. & Michl, J. Recent advances in singlet fission. Annu. Rev. Phys. Chem. 64, 361–386 (2013).

    Article  CAS  Google Scholar 

  12. Varnavski, O. et al. High yield ultrafast intramolecular singlet exciton fission in a quinoidal bithiophene. J. Phys. Chem. Lett. 6, 1375–1384 (2015).

    Article  CAS  PubMed  Google Scholar 

  13. Hu, P. & Wu, J. Modern zethrene chemistry. Can. J. Chem. 95, 223–233 (2017).

    Article  CAS  Google Scholar 

  14. Zeng, W. et al. Super-heptazethrene. Angew. Chem. Int. Ed. 55, 8615–8619 (2016).

    Article  CAS  Google Scholar 

  15. Sun, Z. et al. Dibenzoheptazethrene isomers with different biradical characters: an exercise of Clar’s aromatic sextet rule in singlet biradicaloids. J. Am. Chem. Soc. 135, 18229–18236 (2013).

    Article  CAS  PubMed  Google Scholar 

  16. Li, Y. et al. Kinetically blocked heptazethreene and octazethrene: closed-shell or open-shell in the ground state? J. Am. Chem. Soc. 134, 14913–14922 (2012).

    Article  CAS  PubMed  Google Scholar 

  17. Konishi, A., Hirao, Y., Kurata, H., Kubo, T. & Nakano, M. Anthenes: model systems for understanding the edge state of graphene nanoribbons. Pure Appl. Chem. 86, 497–595 (2014).

    Article  CAS  Google Scholar 

  18. Konishi, A. et al. Synthesis and characterization of quarteranthene: elucidating the characteristics of the edge state of graphene nanoribbons at the molecular level. J. Am. Chem. Soc. 135, 1430–1437 (2013).

    Article  CAS  PubMed  Google Scholar 

  19. Kubo, T. et al. Four-stage amphoteric redox properties and biradicaloid character of tetra-tert-butyldicyclopenta[b;d]thieno[1,2,3-cd;5,6,7-c′d]diphenalene. Angew. Chem. Int. Ed. 43, 6474–5479 (2004).

    Article  CAS  Google Scholar 

  20. Shimizu, A. et al. Alternating covalent bonding interactions in a one-dimensional chain of a phenalenyl-based singlet biradical molecule having Kekulé structures. J. Am. Chem. Soc. 132, 14421–14428 (2010).

    Article  CAS  PubMed  Google Scholar 

  21. Shimizu, A. et al. Aromaticity and π-bond covalency: prominent intermolecular covalent bonding interaction of a Kekulé hydrocarbon with very significant singlet biradical character. Chem. Commun. 48, 5629–5631 (2012).

    Article  CAS  Google Scholar 

  22. Frederickson, C. K., Rose, B. D. & Haley, M. M. Explorations of the indenofluorenes and expanded quinoidal analogues. Acc. Chem. Res. 50, 977–987 (2017).

    Article  CAS  PubMed  Google Scholar 

  23. Chase, D. T. et al. 6,12-Diarylindeno[1,2-b]fluorenes: synthesis photophysics, and ambipolar OFETs. J. Am. Chem. Soc. 134, 10349–10352 (2012).

    Article  CAS  PubMed  Google Scholar 

  24. Shimizu, A. et al. Indeno[2,1-b]fluorene: a 20-π-electron hydrocarbon with very low-energy light absorption. Angew. Chem. Int. Ed. 52, 6076–6079 (2013).

    Article  CAS  Google Scholar 

  25. Young, B. S. et al. Synthesis and properties of fully-conjugated indacenedithiophenes. Chem. Sci. 5, 1008–1014 (2014).

    Article  CAS  PubMed  Google Scholar 

  26. Marshall, J. L. et al. Indacenodibeznothiophenes: synthesis, optoelectronic properties and materials applications of molecules with strong antiaromatic character. Chem. Sci. 7, 5547–5558 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Miyoshi, H. et al. Fluoreno[2,3-b]fluorene vs. indeno[2,1-b]fluorene: unusual relationship between the number of π electrons and excitation energy in m-quinodimethane-type singlet diradicaloids. J. Org. Chem. 82, 1380–1388 (2017).

    Article  CAS  PubMed  Google Scholar 

  28. Barker, J. E., Frederickson, C. K., Jones, M. H., Zakharov, L. N. & Haley, M. M. Synthesis and properties of quinoidal fluorenofluorenes. Org. Lett. 19, 5312–5315 (2017).

    Article  CAS  PubMed  Google Scholar 

  29. Casado, J. Para-quinodimethanes: a unified review of the quinoidal-versus-aromatic competition and its implications. Top. Curr. Chem. 375, 73 (2017).

    Article  CAS  Google Scholar 

  30. Zeng, Z. & Wu, J. Stable π-extended p-quinodimethanes: synthesis and tunable ground states. Chem. Rec. 15, 322–328 (2015).

    Article  CAS  PubMed  Google Scholar 

  31. Zeng, Z. et al. Pushing extended p-quinodimethanes to the limit: stable tetracyano-oligo(N-annulated perylene)quiniodimethanes with tunable ground states. J. Am. Chem. Soc. 135, 6363–6371 (2013).

    Article  CAS  PubMed  Google Scholar 

  32. Bendikov, M. et al. Oligoacenes: theoretical predictions of open-shell diradical ground states. J. Am. Chem. Soc. 126, 7416–7417 (2004).

    Article  CAS  PubMed  Google Scholar 

  33. Jiang, D. E. & Dai, S. Electronic ground state of higher acenes. J. Phys. Chem. 112, 332–335 (2008).

    Article  CAS  Google Scholar 

  34. Purushothaman, B., Bruzek, M., Parkin, S. R., Miller, A. & Anthony, J. E. Synthesis and structural characterization of crystalline nonacenes. Angew. Chem. Int. Ed. 50, 7013–7017 (2011).

    Article  CAS  Google Scholar 

  35. Kubo, T. Recent progress in quinoidal singlet biradical molecules. Chem. Lett. 4, 111–122 (2015).

    Article  CAS  Google Scholar 

  36. Sun, Z., Zeng, Z. & Wu, J. Extended zethrenes, p-quinodimethanes and periacenes with a biradical ground state. Acc. Chem. Res. 47, 2582–2591 (2014).

    Article  CAS  PubMed  Google Scholar 

  37. Abe, M. Diradicals. Chem. Rev. 113, 7011–7088 (2013).

    Article  CAS  PubMed  Google Scholar 

  38. Nakano, M. Electronic structure of open-shell singlet molecules: diradical character viewpoint. Top. Curr. Chem. 375, 47 (2017).

    Article  CAS  Google Scholar 

  39. Zeng, Z. et al. Pro-aromatic and anti-aromatic π-conjugated molecules: an irresistible wish to become diradicals. Chem. Soc. Rev. 44, 6578–6596 (2015).

    Article  CAS  Google Scholar 

  40. Clar, E. The Aromatic Sextet (Wiley, London, 1972).

    Google Scholar 

  41. Yamaguchi, K. The electronic structure of biradicals in the unrestricted Hartree–Fock approximation. Chem. Phys. Lett. 33, 330–335 (1975).

    Article  CAS  Google Scholar 

  42. Zeng, W. et al. Phenalenyl-fused porphyrins with different ground states. Chem. Sci. 6, 2427–2433 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Shi, X. et al. Benzo-thia-fused [n]thienoacenequinodimethanes with small to moderate diradical characters: the role of pro-aromaticity versus antiaromatity. Chem. Sci. 7, 3036–3046 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Frisch, M. J. et al. Gaussian 09, Revision B.01 (Gaussian, 2009).

  45. Fukuda, K., Nagami, T., Fujiyoshi, J. & Nakano, M. Interplay between open-shell character, aromaticity, and second hyperpolarizablilities in indenofluorenes. J. Phys. Chem. A 119, 10620–10627 (2015).

    Article  CAS  PubMed  Google Scholar 

  46. Bernard, Y. A., Shao, Y. & Krylov, A. I. General formulation of spin-flip time-dependent density functional theory using non-collinear kernels: theory, implementation, and benchmarks. J. Chem. Phys. 136, 204103 (2012).

    Article  CAS  PubMed  Google Scholar 

  47. Shao, Y. et al. Advances in molecular quantum chemistry contained the Q-chem 4 program package. Mol. Phys. 113, 184–215 (2014).

    Article  CAS  Google Scholar 

  48. Knall, A. et al. Naphthacenodithiophene based polymers—new members of the acenodithiophene family exhibiting high mobility and power conversion efficiency. Adv. Funct. Mater. 26, 6961–6969 (2016).

    Article  CAS  Google Scholar 

  49. Nakagawa, H., Kawai, S., Nakashima, T. & Kawai, T. Synthesis of photochemical reaction of photochromic terarylene having a leaving methoxy group. Org. Lett. 11, 1475–1478 (2009).

    Article  CAS  PubMed  Google Scholar 

  50. Schleyer, Pv. R. et al. Dissected nucleus-independent chemical shift analysis of π-aromaticity and antiaromaticity. Org. Lett. 3, 2465–2468 (2001).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

This work was supported by the US National Science Foundation (CHE-1565780), by the Spanish Government, MINECO (CTQ2015-69391-P, CTQ2016-80955 and CTQ2017-87201-P) and Generalitat Valenciana (Prometeo II / 2014 / 076), and by the Japan Society for the Promotion of Science (JSPS, KAKENHI grant nos. JP15J04949, JP25248007, JP17H05157, JP18H01943, JP18J10067 and JP26107004). The authors acknowledge support from the Biomolecular Mass Spectrometry Core of the Environmental Health Sciences Core Center at Oregon State University (NIH P30ES000210). M.N. also thanks King Khalid University for financial support through grant no. RCAMS/KKU/001-16 from the Research Center for Advanced Materials Science at King Khalid University, Kingdom of Saudi Arabia. Theoretical calculations were partly performed at the Research Center for Computational Science, Okazaki, Japan.

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Authors

Contributions

J.J.D. and M.T. designed and carried out the experiments. J.J.D. analysed the data and wrote the manuscript. M.M.H. conceived the project and played a critical role in discussions of the experimental design, project direction, experiments and results, and preparation of the manuscript. C.J.G.G. carried out the SQUID magnetic measurements and DSC measurements. G.L.E. acquired and analysed the cyclic voltammetry data and performed the Raman spectroscopic measurements. L.N.Z. acquired and analysed the X-ray crystallographic data. J.C. interpreted the spectroscopic data and co-wrote the paper. R.K., S.T. and M.N. performed the calculations and wrote the discussion on geometry optimization, the open-shell character and the S–T gaps. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Masayoshi Nakano, Juan Casado or Michael M. Haley.

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Supplementary information

Supplementary information

Synthesis details and copies of NMR spectra, variable temperature NMR and SQUID magnetic data, X-ray diffraction details for 10a, cyclic voltammetry and Raman spectroscopy, additional computational details and cartesian coordinates of calculated systems, and a detailed explanation of the relationship between S–T gap and diradical character

Crystallographic data

CIF for compound 10a; CCDC reference: 1832752

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Dressler, J.J., Teraoka, M., Espejo, G.L. et al. Thiophene and its sulfur inhibit indenoindenodibenzothiophene diradicals from low-energy lying thermal triplets. Nature Chem 10, 1134–1140 (2018). https://doi.org/10.1038/s41557-018-0133-5

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