Indenofluorene Scaffolds

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 the singlet-triplet energy gap of the diradicaloid species.

Selected Publications

“From Solution To Surface: Persistence Of The Diradical Character Of A Diindenoanthracene Derivative On A Metallic Substrate”

Hieulle, J.; Garcia Fernandez, C.; Friedrich, N.; Vegliante, A.; Sanz, S.; Sanchez-Portal, D.; Haley, M.M.; Casado, Juan.; Frederiksen, T.; Ignacio Pascual, J. J. Phys. Chem. Lett. 2023, 14, 11506-11512.
DOI: 10.1021/acs.jpclett.3c02401

**“Tetra-tert-butyl-s-Indacene Is A Bond Localized C_2h Structure And A Challenge For Computational Chemistry”**

Karas, L.S.; Jalife, S.; Viesser, R.V.; Soares, J.V.; Haley, M.M.; Wu, J.I. Angew. Chem. Int. Ed. 2023, 62, e202307379.
DOI: 10.1002/anie.202307379
See Team Profile: DOI: 10.1002/anie.202317561

“Comparison of Antiaromatic Properties in a Series of Structurally Isomeric Naphthothiophene-fused s-Indacenes”

Warren, G.I.; Zocchi, L.J.; Zakharov, L.N.; Haley, M.M. Chem. Eur. J. 2023, e202301153.
DOI: 10.1002/chem.202301153

“Orbital Nature of Carboionic Monoradicals Made from Diradicals”

A. Cardenas Valdivia, Y. Dai, F. Rambaldi, Z. Zhou, Y. Zhu, Z. Wei, J. E. Barker, J. J. Dressler, M. A. Petrukina, M. M. Haley, F. Negri and J. Casado, Chem. Eur. J.2023, 29, e202300388.
DOI: 10.1002/chem.202300388

“Polycyclic Hydrocarbons from [4n]Annulenes: Correlation versus Hybridization Forces in the Formation of Diradicaloids”

Quintero, S.M.; Haley, M.M.; Ketesz, M.; Casado, J. Angew. Chem. Int. Ed. 2022, 61, e202209138.
DOI: 10.1002/anie.202209138

“A Tale of Two Isomers: Enhanced Antiaromaticity/Diradical Character versus Deleterious Ring-Opening of Benzofuran-fused s-Indacenes and Dicyclopenta[b,g]naphthalenes”

Barker, J. E.; Price, T. W.; Karas, L. J.;Kishi, R.;MacMillan, S. N.; Zakharov, L. N.; Gómez-García, C. J.; Wu, J. I.; Nakano, M.; Haley, M. M. Angew. Chem. Int. Ed.2021, 60, 22385-22392.
DOI: 10.1002/anie.202107855

“OCELOT: An Infrastructure for Data-Driven Research to Discover and Design Crystalline Organic Semiconductors”

Ai, Q.; Bhat, V.; Ryno, S. M.; Jarolimek, K.; Sornberger, P.; Smith, A.; Haley, M. M.; Anthony, J. E.; Risko, C. J. Chem. Phys.2021, 154, 174705.
DOI: 10.1063/5.0048714

“Enhancing the Antiaromaticity of s-Indacene Through Naphthothiophene Fusion”

Warren, G. I.; Barker, J. E.; Zakharov, L. N.; Haley, M. M. Org. Lett. 2021, 23, 5012-5017.
DOI: 10.1021/acs.orglett.1c01514

“Monoradicals and Diradicals of Dibenzofluoreno[3,2-b]fluorene Isomers: Mechanisms of Electronic Delocalization”

Hayashi, H.; Barker, J. E.; Valdivia, A. C.; Kishi, R.; MacMillan, S. N.; Gómez-García, C. J.; Miyauchi, H.; Nakamura, Y.; Nakano, M.; Kato, S.-I.; Haley, M. M.; Casado, J. J. Am. Chem. Soc. 2020 142, 20444-20455.
DOI: 10.1021/jacs.0c09588

“Late-stage Modification of Electronic properties of Antiaromatic and Diradicaloid Indeno[1,2-b]fluorene Analogues via Sulfur Oxidation”

Dressler, J. J.; Barker, J. E.; Karas, L. J.; Hashimoto, H.; Kishi, R.; Zakharov, L. N. MacMillan, S. N.; Gómez-García, C. J.; Nakano, M.; Wu, J. I.; Haley, M. M. J. Org. Chem. 2020 85, 10846-10857.
DOI: 10.1021/acs.joc.0c01387

“Learning how to fine-tune diradical properties by structure refinement”

Dressler, J. J.; Haley, M. M. J. Phys. Org. Chem. 2020, 33, e4114.
DOI: 10.1002/poc.4114

“Diindenoanthracene Diradicaloids Enable Rational, Incremental Tuning of Their Singlet-Triplet Energy Gaps”

Dressler, J. J.; Valdivia, A. C.; Kishi, R.; Rudebusch, G. E.; Ventura, A. M.; Chastain, B. E.; Gómez-García, C. J.; Zakharov, L. N.; Nakano, M.; Casado, J.; Haley, M. M. Chem 2020, 6, 1353-1368.
DOI: 10.1016/j.chempr.2020.02.010

“Interplay of Biradicaloid Character and Singlet/Triplet Energy Splitting for cis-/trans-Diindenoacenes and Related Benzothiophene-Capped Oligomers as Revealed by Extended Multireference Calculations”

Nieman, R.; Silva, N. J.; Aquino, A. J. A.; Haley, M. M.; Lischka, H. J. Org. Chem. 2020, 85, 3664-3675.
DOI: 10.1021/acs.joc.9b03308

“Molecule Isomerism Modulates the Diradical Properties of Stable Singlet Diradicaloids”

Barker, J. E.; Dressler, J. J.; Valdivia, A. C.; Kishi, R.; Strand, E. T.; Zakharov, L .N; MacMillan, S. N.; Gómez-García, C. J.; Nakano, M.; Casado, J.; Haley, M. M. J. Am. Chem. Soc. 2020, 142, 1548-1555.
DOI: 10.1021/jacs.9b11898

“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, 1279-1287.
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. 2017, 48, 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