A Combination of B- and N-Doped π-Systems Enabling Systematic Tuning of Electronic Structures and Properties

Doping heteroatoms into polycyclic aromatic hydrocarbons (PAHs) may alter their structures and thereby physical properties. This study reports the construction of B/N-codoped PAHs via combining the B- and N-doped pi-systems. Two pi-extended B/N-codoped PAHs were synthesized through the Mallory photoreaction. Both feature a C48BN2 pi-skeleton, which is assembled by linearly fusing three substructures including B-doped and sp2-hybridized N-doped pi-moieties and one pyrene unit. In comparison to the pristine B-doped analog, their intramolecular charge transfer (ICT) states are distinctly modulated by the fused N-doped pi-system and the further incorporated cyano group, leading to their tunable optical properties, as revealed by detailed theoretical and experimental analysis. Furthermore, these three molecules have sufficient Lewis acidity and can coordinate with Lewis base to form Lewis acid-base adducts, and notably, such intermolecular complexation can further dynamically modulate their ICT transitions and thereby photophysical properties, such as producing blue, green and red fluorescence. B/N-codoped polycyclic aromatic hydrocarbons (PAHs) were constructed via combining the B- and N-doped pi-systems. Two B/N-codoped PAHs were synthesized through the Mallory photoreaction, and their electronic structures and optical properties could be effectively modulated via static and dynamic control of intramolecular charge transfer states.image

Automated summary

B/N-codoped polycyclic aromatic hydrocarbons (PAHs) were constructed by combining the B- and N-doped π-systems, enabling tunable structures and optical properties.