Fig. 2: HOMO and LUMO energy level diagram for the two types of building blocks for constructing D-A pairs.

The TAPTc and TAPBc represent the core part (without the amine group) of the amino-based monomers (TAPT and TAPB), and the Clc, Hc, OCCHc, OHc and OMec represent the core part (without the aldehyde group) of the terephthalaldehyde-based monomers.