Small molecules like (aza-)acenes and arenes are important organic semiconductors with application in organic transistors (OFETs) or organic solar cells (OPV). Their tendency to crystallize forming π-stacked arrangements is beneficial for OFETs, but detrimental for OPV due to phase separation. For multilayer-devices such as bulk-heterojunction OPV cells, smooth films are desired. Appending alkyl-/alkoxy- or aryl-side-chains can lower the crystallinity significantly, but often results in a distinct reduction of the charge carrier mobilities due to increased distances between the aromatic systems. This work focuses on the synthesis of azaacene tetramers, connected via cyclooctatetraene- (COT) backbones. The resulting constructs link the acene units via direct CC bonds without the need of an additional connector. The tetramers show strong interactions across the COT backbone resulting in a significantly redshifted absorption compared to their consanguine monomeric counterparts. The crystal structures of 1a and 1b show close packing of adjacent molecules and prove the tetrahedral shape spanned by the acene subunits. As expected, due to the three dimensional shape, 3a and 3b form smooth spin-coated films in contrast to their corresponding crystalline monomers.

Cyclooctatetraene-based acene tetramers

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.