Monodisperse conjugated molecules are useful materials for investigating structure-property relationships as they provide the opportunity to systematically perform structure property studies under well-defined conditions. Two-dimensional cross-conjugated molecules that feature two perpendicular π-conjugated linear “arms” connected through a central aromatic core are particularly promising. The spatial segregation of the frontier molecular orbitals within these “cruciforms,” makes it possible to semi-independently alter the LUMO or the HOMO through judicious selection and strategic positioning of substituents around the central molecule.[1] Amongst cruciforms, the benzo[1,2-d:4,5-d′]bisoxazole (BBO)-based systems are unique since one of the conjugation pathways, along the 2,6-axis encompasses two oxazole rings whereas the 4,8-axis goes through the central benzene ring. This structure allows for synthesis of number of different materials with tunable properties.[2-3] Using a combination of organic synthesis, theoretical calculations and physical measurements we are systematically investigating the development of novel cross-conjugated oligomers. The work has produced wide band-gap blue-light emitting materials for use in OLEDs and narrow band gap cruciform with energy levels suitable for use in OPVs. We are actively pursuing new derivatives and our recent discoveries in this area will be presented.
[1] B. C. Tlach, A. L. Tomlinson, K. D. Morgan, C. R. Collins, M. D. Zenner, M. Jeffries-EL, Australian Journal of Chemistry 67, 711 (2014). [2] B. C. Tlach, A. L. Tomlinson, A. Bhuwalka, M. Jeffries-El, Journal of Organic Chemistry 76, 8670 (2011). [3] B. C. Tlach, A. L. Tomlinson, A. G. Ryno, D. D. Knoble, D. L. Drochner,
K. J. Krager, M. Jeffries-EL, Journal of Organic Chemistry 78, 6570 (2013).