Indeno[1,2-b]fluorenes (IFs), while containing 4n π-electrons, are best described as two aromatic benzene rings fused to a weakly paratropic s-indacene core. In this study, we find that replacement of the outer benzene rings of an IF with benzothiophenes allows the antiaromaticity of the central s-indacene to strongly reassert itself. Herein we report a combined synthetic, computational, structural, and materials study of anti- and syn-indacenodibenzothiophenes (IDBTs). We have developed an efficient and scalable synthesis for preparation of a series of aryl- and ethynyl-substituted IDBTs. NICS-XY scans and ACID calculations reveal an increasingly antiaromatic core from [1,2-b]IF to anti-IDBT, with syn-IDBT being nearly as antiaromatic as the parent s-indacene. As an initial evaluation, the intermolecular electronic couplings and electronic band structure of a diethynyl anti-IDBT derivative reveal the potential for hole and/or electron transport. OFETs constructed using this molecule show the highest hole mobilities yet achieved for a fully conjugated IF derivative.
|Number of pages
|Published - 2016
Bibliographical noteFunding Information:
We thank the National Science Foundation (CHE-1301485) for support of the U Oregon research, as well as for support in the form of an instrumentation grant (CHE-1427987). The device studies at WFU were supported by the National Science Foundation under grant ECCS-1254757. C. R. thanks the University of Kentucky Vice President for Research for start-up funds, and Dr Gjergji Sini for fruitful discussions. K. U. was partly supported by the Osaka University Scholarship for Short-term Overseas Research Activities 2013. HRMS were obtained at the Mass Spectrometry Facilities and Services Core of the Environmental Health Sciences Center, Oregon State University, supported by grant #L30-CS00210, National Institute of Environmental Health Sciences, National Institutes of Health.
© 2016 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Chemistry (all)