Polycyclic hydrocarbons that possess extended π-conjugation are of tremendous interest due to their potential use in optical and  electronic device applications. While a majority of studies have focused on acenes and their derivatives (for example, compounds 1-2), these systems are susceptible to degradation due to environmental effects, through oxidative or photolytic pathways; thus, there is a pressing need for alternative, acene-like topologies. Current research in the lab is focused on molecules based on or inspired by the indenofluorene (IF) skeleton, such as compounds 3-5. Over the last few years, we have adapted and/or developed general methods for the assembly of a variety of fully conjugated IF derivatives and initiated exploration of their materials properties. We have shown that IFs can be prepared in gram quantities with good overall yields and excellent purity using methodologies amenable to large-scale production.

 

In addition to being challenging synthetic targets, IFs help to provide answers to fundamental questions about structure, bonding, and reactivity in expanded, conjugated structures. They also have the potential to act as rigid, planar, electron-accepting cores for the formation of advanced materials with novel electronic properties. We are exploiting the materials potential of IFs via a combined experimental and theoretical approach, with an emphasis toward the use of indenofluorenes as organic semiconductors in devices. Importantly, we have demonstrated that single crystals, as well OFETs of IFs can serve as an active layer in an organic field-effect transistors that exhibit ambipolar behavior.

Recent work in the group has shown that we can access open-shell variants and tune their singlet-triplet energy gap.

Selected Publications

 

“Organic Semiconductors Derived from Dinaphtho-Fused s-Indacenes: How Molecular Structure and Film Morphology Influence Thin-Film Transistor Performance”

Zeidell, A. M.; Jennings, L.; Frederickson, C. K.; Ai, Q.; Dressler, J. J.; Zakharov, L. N.; Risko, C.; Haley, M. M.; Jurchescu, O. D. Chem. Mater. 2019, 31, 6962-6970.
DOI: 10.1021/acs.chemmater.9b01436

Serendipitous Rediscovery of the Facile Cyclization of Z,Z-3,5-Octadiene-1,7-diyne Derivatives to Afford Stable, Substituted Naphthocyclobutadienes”

Barker, J. E.; Kodama, T.; Song, M. K.; Frederickson, C. K.; Jousselin-Oba, T.; Zakharov, L. N.; Marrot, J.; Frigoli, M.; Johnson, R. P.; Haley, M. M. ChemPlusChem 2019, 84, 665-672.
DOI: 10.1002/cplu.201800605

Tuning Redox Properties and Self-Assembly of Thienoacene-Extended Tetrathiafulvalenes.”

Andersen, C. L.; Zalibera, M.; Lušpai, K.; Christensen, M. A.; Darvasiová, D; Lukes, B.; Rapta, P.; Haley, M. M.; Hammerich, O.; Nielsen, M. B. ChemPlusChem 2019, 84, in press.
DOI: 10.1002/cplu.201800626

Synthesis and Properties of Benzo-Fused Indeno[2,1-c]fluorenes

Jousselin-Oba, T.; Deal, P. E.; Fix, A. G.; Frederickson, C. K.; Vonnegut, C. L.; Yassar, Abderrahim, Y.; Zakharov, L. N.; Frigoli, M.; Haley, M. M. Chem. Asian J. 2019, 14, 1737-1744.
DOI: 10.1002/asia.201801684

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

Dressler, J. J.; Teraoka, M; Espejo, G. L.; Kishi, R.; Takamuku, S.; Gómez-García, C. J.; Zakharov, L. N.; Nakano, M.; Casado, J.; Haley, M. M. Nat. Chem. 2018, 10, 1134-1140.
DOI: 10.1038/s41557-018-0133-5

Synthesis and Characterization of a Fluorescent Dianthracenoindacene

Frederickson, C. K.; Barker, J. E.; Dressler, J. J.; Zhou, Z.; Hanks, E. R.; Bard, J. P.; Zakharov, L. N.; Petrukhina, M. A.; Haley, M. M. Synlett 2018 29, 2562-2566.
DOI: 10.1055/s-0037-1610280

Synthesis of 7,12-Dimesitylindeno[1,2-a]fluorene, the Sole Unknown Indenofluorene Regioisomer, and Crystallographic Characterization via Its Dianion

Dressler, J. J.; Zhou, Z.; Marshall, J. L.; Kishi, R.; Takamuku, S.; Wei, Z.; Spisak, S.; Nakano, M.; Petrukhina, M. A.; Haley, M. M. Angew. Chem. Int. Ed. 201748, 15363–15367.
DOI: 10.1002/anie.201709282

Synthesis and Properties of Quinoidal Fluorenofluorenes

Barker, J. E.; Frederickson, C. K.; Jones, M. H.; Zakharov, L. N.; Haley, M. M. Org. Lett. 2017, 19, 5312-5315.
DOI: 10.1021/acs.orglett.7b02605

Expanded Indacene-Tetrathiafulvalene Scaffolds: Structural Implications for Redox Properties and Association Behavior


Petersen, J. F.; Frederickson, C. K.; Marshall, J. L.; Rudebusch, G. E.; Zakharov, L. N.; Hammerich, O.; Haley, M. M.; Nielsen, M. B. Chem. Eur. J. 2017, 23, 13120-13130.
DOI: 10.1002/chem.201702347

Explorations of the Indenofluorenes and Expanded Quinoidal Analogues

Frederickson, C. K.; Rose, B. D.; Haley, M. M. Acc. Chem. Res. 2017, 50, 977-987.
DOI: 10.1021/acs.accounts.7b00004

Modulating Paratropicity Strength in Diareno-Fused Antiaromatics


Frederickson, C. K.; Zakharov, L. N.; Haley, M. M. J. Am. Chem. Soc. 2016, 138, 16827-16838.
DOI: 10.1021/jacs.6b11397

A Biradical Balancing Act: Redox Amphoterism in a Diindenoanthracene Derivative Results from Quinoidal Acceptor and Aromatic Donor Motifs


Rudebusch, G. E.; Espejo, G. L.; Zafra, J. L.; Peña-Alvarez, M.; Spisak, S. N.; Fukuda, K.; Wei, Z.; Nakano, M.; Petrikhina, M. A.; Casado, J.; Haley, M. M. J. Am. Chem. Soc. 2016, 138, 12648-12654.
DOI: 10.1021/jacs.6b07882

Diindeno-fusion of an anthracene as a design strategy for stable organic biradicals


Rudebusch, G. E.; Zafra, J. L.; Jorner, K.; Fukuda, K.; Marshall. J. L.; Arrechea-Marcos, I.; Espejo, G. L.; Ortiz, R. P; Gómez-García, C. J.; Zakharov, L. N.; Nakano, M.; Ottoson, H.; Casado, J.; Haley, M. M. Nat. Chem. 2016, 8, 753-759.
DOI: 10.1038/nchem.2518

Indacenodibenzothiophenes: synthesis, optoelectronic properties and materials applications of molecules with strong antiaromatic character


Marshall. J. L.; Uchida, K.; Frederickson, C. K.; Schütt, C.; Zeidell, A. M.; Goetz, K. P.; Finn, T. W.; Jarolimek, K.; Zakharov, L. N.; Risko, C.; Herges, R.; Jurchescu, O. D.; Haley, M. M. Chem. Sci. 2016, 7, 5547-5558.
DOI: 10.1039/C6SC00950F

Synthesis and Characterization of Two Unsymmetrical Indenofluorene Analogues: Benzo[5,6]-s-indaceno[1,2-b]thiophene and Benzo[5,6]-s-indaceno[2,1-b]thiophene


Marshall. J. L.; O’Neal, N. J.; Zakharov, L. N.; Haley, M. M. J. Org. Chem. 2016, 81, 3674-3680.
DOI: 10.1021/acs.joc.6b00340

Synthesis of Open-Shell Ladder π-Systems by Catalytic C–H Annulation of Diarylacetylenes


Maekawa, T.; Ueno, H.; Segawa, Y.; Haley, M. M.; Itami, K. Chem. Sci. 2016, 7, 650-654.
DOI: 10.1039/C5SC03391H

Synthesis and properties of fully conjugated indacenediselenophene and diindenoselenophene derivatives


Marshall. J. L.; Rudebusch, G. E.; Vonnegut, C. L.; Zakharov, L. N.; Haley, M. M. Tetrahedron Lett. 2015, 56, 3235-3239.
DOI: 10.1016/j.tetlet.2014.12.096

Synthesis and Optoelectronic Properties of Indeno[1,2-b]fluorene-6,12-dione Donor–Acceptor–Donor Triads


Frederickson, C. K.; Haley, M. M. J. Org. Chem. 2014, 79, 11241-11245.
DOI: 10.1021/jo502009p

Unusually short excited state lifetimes of indenofluorene and fluorenofluorene derivatives result from a conical intersection


Rose, B. D.; Shoerb, L. E.; Wasielewski, M. R.; Haley, M. M. Chem. Phys. Lett. 2014, 616-617, 137-141.
DOI: 10.1016/j.cplett.2014.10.031

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing


Rose, B. D.; Santa Maria, P. J.; Fix, A.G.; Vonnegut, C. L.; Zakharov, L.; Parkin, S. R.; Haley, M. M. Beilstein J. Org. Chem. 2014, 10, 2122–2130.
DOI: 10.3762/bjoc.10.219

Quinoidal diindenothienoacenes: Synthesis and properties of new functional organic materials


Rudebusch, G. E.; Fix, A. G.; Henthorn, H. A.; Vonnegut, C. L.; Zakharov, L.; Haley, M. M. Chem. Sci. 2014, 5, 3627-3633.
DOI: 10.1039/C4SC01432D

Experimental and Computational Studies of the Neutral and Reduced States of Indeno[1,2-b]fluorene


Rose, B. D.; Sumner, N. J.; Filatov, A. S.; Peters, S. J.; Zakharov, L. N.; Petrukhina, M. A.; Haley, M. M. J. Am. Chem. Soc. 2014, 136, 9181–9189.
DOI: 10.1021/ja503870z

Synthesis and properties of fully-conjugated indacenedithiophenes


Young, B. S.; Chase, D. T.; Marshall, J. L.; Vonnegut, C. L.; Zakharov, L. N.; Haley, M. M. Chem. Sci. 2014, 5, 1008-1014.
DOI: 10.1039/C3SC53181C

Indeno[2,1-c]fluorene: A New Electron-Accepting Scaffold for Organic Electronics


Fix, A. G.; Deal, P. E.; Vonnegut, C. L.; Rose, B. D.; Zakharov, L. N.; Haley, M. M. Org. Lett. 2013, 15, 1362–1365.
DOI: 10.1021/ol400318z

6,12-Diarylindeno[1,2-b]fluorenes: Syntheses, Photophysics, and Ambipolar OFETs


Chase, D. T.; Fix, A. G.; Kang, S. J.; Rose, B. D.; Weber, C. D.; Zhong, Y.; Zakharov, L. N.; Lonergan, M. C.; Nuckolls, C.; Haley, M. M. J. Am. Chem. Soc. 2012, 134, 10349–10352.
DOI: 10.1021/ja303402p

Fluoreno[4,3-c]fluorene: A Closed-Shell, Fully Conjugated Hydrocarbon


Rose, B. D.; Vonnegut, C. L.; Zakharov, L. N.; Haley, M. M. Org. Lett. 2012, 14, 2426–2429.
DOI: 10.1021/ol300942z

Electron-Accepting 6,12-Diethynylindeno[1,2-b]fluorenes: Synthesis, Crystal Structures, and Photophysical Properties


Chase, D. T.; Fix, A. G.; Rose, B. D.; Weber, C. D.; Nobusue, S.; Stockwell, C. E.; Zakharov, L. N.; Lonergan, M. C.; Haley, M. M. Angew. Chem. Int. Ed. 2011, 50, 11103–11106.
DOI: 10.1002/anie.201104797

Synthesis, Crystal Structures, and Photophysical Properties of Electron-Accepting Diethynylindenofluorenediones


Rose, B. D.; Chase, D. T.; Weber, C. D.; Zakharov, L. N.; Lonergan, M. C.; Haley, M. M. Org. Lett. 2011, 13, 2106–2109.
DOI: 10.1021/ol200525g

Indeno[1,2-b]fluorenes: Fully Conjugated Antiaromatic Analogues of Acenes


Chase, D. T.; Rose, B. D.; McClintock, S. P.; Zakharov, L. N.; Haley, M. M. Angew. Chem. Int. Ed. 2011, 50, 1127–1130.
DOI: 10.1002/anie.201006312