β-Disubstituted Pentacene Derivatives: Thin Film StructuralProperties and Four-Probe Field Effect Mobility

0582837 - ÚOCHB 2025 RIV US eng J - Journal Article
Aliouat, M. Y. - Cristiano, F. - Abbassi, L. - Escoubas, S. - Mesnilgrente, F. - Salvagnac, L. - Šámal, Michal - Rybáček, Jiří - Sturm, L. - Gourdon, A. - Jančařík, A. - Seguy, I.
β-Disubstituted Pentacene Derivatives: Thin Film StructuralProperties and Four-Probe Field Effect Mobility.
ChemPlusChem. Roč. 89, č. 4 (2024), č. článku e202300611. ISSN 2192-6506. E-ISSN 2192-6506
Institutional support: RVO:61388963
Keywords : acenes * charge mobility * nanostructures * organic electronics * organic field effect transistors
OECD category: Organic chemistry
Impact factor: 3.4, year: 2022
Method of publishing: Open access
https://doi.org/10.1002/cplu.202300611

2,9- and 2,10-diphenylpentacene were synthesized by direct C-H borylation of ketal-protected pentacene, followed by halodeboronation, resolution of the dihalo isomers, Suzuki arylation, cleavage of the ketals and decarbonylation in the solid state. They were studied as main active components in organic field effect transistors (OFETs). Diphenyl substitution of pentacene affects the unit cell dimensions only slightly, preserving a face to edge molecular packing in the first layers of thin films evaporated on SiO2 substrates. Both isomers self-assemble into nanoribbons during the thin film growth upon vapor deposition. The similarity between the surface induced phases of the 2,9-isomer and unsubstituted pentacene leads to similar 4-probe hole mobilities, i. e. 0.13 cm2 V-1 s-1 for the former. Whereas 2,9-disubstitution thus does essentially preserve the thin film characteristics of unsubstituted pentacene, 2,10-disubstitution is detrimental to the molecular ordering in the thin films and therefore to the field effect mobility which is only 0.07 cm2 V-1 s-1. The known strong enhancement of field effect mobility observed upon diphenyl substitution of anthracene can thus not be emulated analogously with pentacene.
Permanent Link: https://hdl.handle.net/11104/0350887