Synthesis and Photophysical Properties of <i>N</i> , <i>N</i> -chelated Boron Complexes Based on Imidazo[1,2- <i>a</i> ]pyridines

Abstract Two imidazo[1,2-a]pyridine-based boron complexes were synthesized using N,N-bidentate ligands composed of imidazo[1,2-a]pyridine and indole units, and their photophysical properties were evaluated. The resulting boron complexes formed stable tetracoordinated structures and exhibited blue emission in solution and cyan emission in the solid state, demonstrating dual-state emission. Fluorescence imaging studies using one complex representative of this group revealed preferential mitochondrial localization in living HeLa cells, highlighting the potential of this molecular scaffold for fluorescent bioimaging applications.