Pyrrolic Type N Directed Borylation Route to BN-PAHs: Tuning the Photophysical Properties by Varying the Conjugation Shape and Size.

Two series of BN-cyclopenta[a]phenalenes have been synthesized through an indole/pyrrole oriented borylation reaction. A total of five compounds are obtained and fully characterized; one of them is unambiguously confirmed by single X-ray crystal structure. Their photophysical properties could be finely tuned through varying the conjugation size and shape of the bottom PAHs applied. Moreover, their response toward fluoride anions was also investigated.