Novel Series of Diaminoanthraquinone-Based π-Extendable Building Blocks with Tunable Optoelectronic Properties.

We have achieved the first series of DAAQ -based building blocks, viz., n -TIPS-DAAQ s ( n = 1-4), and unraveled a rational design of their π-extension. Sequentially increasing numbers ( n ) of the exocyclic π-linkers showed (a) a systematic bathochromic shift in both absorption and emission spectra, (b) selective stabilization of the lowest-unoccupied molecular orbital (LUMO), and (c) unselective changes in the S 0 /S 1 states. To our surprise, the LUMO level of 4-TIPS-DAAQ (-3.72 eV) was found to be comparable to that of PC 60 BM.