Structure and electronics in dimeric boron π expanded azine and salphen complexes

Although boron-based fluorophores incorporating nitrogenous chelating ligands have received much attention, there has been little work on examples of boron-salphen and azine derivatives. In this report, we present several it expanded boron salphen type complexes, incorporating both bis(2-hydroxy-naphthaldehyde)azine as well as ortho, meta and para variants of the analogous 2-hydroxynaphthalde-hyde salphen compounds. For the azine, we observed only the formation of a single BF 2 adduct, while for the naphth-phen compounds dimeric BF 2 binding was observed. All new compounds were fully characterized via X-ray diffraction, and both DFT. and TDDFT. studies were carried out to probe the electronic structures of these fluorophores