Figure 2 (a) Optimized geometries (top: top view; bottom: side
view) of the
three
NFREAs. (b) 2D-GIWAXS patterns of neat NoCA-17, NoCA-18, and NoCA-19
films.
compared to IC-2Cl, leading to a more efficient intramolecular charge
transfer effect. Accordingly, NoCA-19 displays a blue-shifted absorption
peak (728 nm) in comparison NoCA-18. Both symmetric acceptors, NoCA-17
and NoCA-18, in the thin film exhibit comparable absorption spectra. In
contrast, the asymmetric acceptor NoCA-19 demonstrates a broadening of
the absorption spectrum in the high-energy region, indicating a unique
stacking arrangement in the solid state.
Table 1 Basic properties of NoCA-17, NoCA-18, and NoCA-19