Syntheses and structures of new luminescent B(III) complexes: BPh2(2-(2-pyridyl)naphtho[b]imidazole) and BF2(2-(2-pyridyl)naphtho[b]imidazole)

A novel chelating ligand, 2-(2-pyridyl)naphtho[b]imidazole (PNI) has been synthesized and structurally characterized. The PNI molecule reacts readily with BPh3 and BF3 to form BPh2(2-(2-pyridyl)naphtho[b]imidazole) (1) and BF2(2-(2-pyridyl)naphtho[b]imidazole) (2), respectively. The structures of PNI and 1 were determined by single crystal X-ray diffraction, while that 2 by spectroscopic methods. The structure of 1 reveals that the boron center is four-coordinated. The electroluminescent device using 1 as the emitting layer shows bright yellow luminescence with a maximum emission peak at 540 nm. Complexes 1 and 2 form a new family of organometallic emitting materials which could be of interest for practical applications.

Graphical abstractWe have demonstrated a novel PNI ligand which is capable of chelating to B(III) center and the resulting complexes possess appreciable photoluminescent efficiency, which could be of interest for practical applications, especially for OLED.Figure optionsDownload full-size imageDownload as PowerPoint slide