Aminopyrimidine-Based Donor–Acceptor Chromophores: Push–Pull versus Aromatic Behaviour
Novel 2-aminopyrimidines substituted with two electron-donor dialkylamino groups and either one dicyanovinyl (4a–d) or one tricyanovinyl (7a–d) electron-acceptor group have been synthesized, and the balance between their push–pull character and their aromatic behaviour has been studied by experimental (spectroscopic, electrochemical and X-ray analysis) and theoretical (DFT/B3LYP/6-31G**) methods. Calculations reveal that the push–pull character is energetically favoured with respect to the preservation of the aromaticity of the pyrimidine ring. X-ray analysis of 7a confirms the theoretical predictions and reveals a strong distortion from planarity due to the steric interaction between the t…
Azatruxene‐Based, Dumbbell‐Shaped, Donor–π‐Bridge–Donor Hole‐Transporting Materials for Perovskite Solar Cells
Three novel donor-π-bridge-donor (D-π-D) hole-transporting materials (HTMs) featuring triazatruxene electron-donating units bridged by different 3,4-ethylenedioxythiophene (EDOT) π-conjugated linkers have been synthesized, characterized, and implemented in mesoporous perovskite solar cells (PSCs). The optoelectronic properties of the new dumbbell-shaped derivatives (DTTXs) are highly influenced by the chemical structure of the EDOT-based linker. Red-shifted absorption and emission and a stronger donor ability were observed in passing from DTTX-1 to DTTX-2 due to the extended π-conjugation. DTTX-3 featured an intramolecular charge transfer between the external triazatruxene units and the azo…