Synthesis and luminescent study of naphthalenedioxyboron compounds for photoelectronic applications

The coordinatively saturated naphthalenedioxyboron compounds were newly synthesized and characterized by 1H-NMR and mass spectrometry. First, the dianion of 2,3-dihydroxynaphthalene (dhn) was coordinated to the boron center by the reaction of dhn and B(OEt)3, resulting in (dhn)B(OEt). (dhn)B(OEt) was then reacted with 2-amino-3-hydroxynaphthalene (an), 8-hydroxyquinoline (q) or 10-hydroxybenzo[h]quinoline (bq) to obtain the coordinatively saturated boron compounds, (dhn)B(an) (1), (dhn)B(q) (2), or (dhn)B(bq) (3). The photophysical properties of the resulting boron compounds were investigated with UV-VIS spectroscopy and photoluminescence (PL) spectroscopy. Their luminescent properties and sublimability were tested for the photoelectronic applications. The absorption bands of these boron compounds 1-3 were observed at below 320, 400, 450 nm, respectively, in the UV-VIS spectra, showing typical ligand-based transitions. The solid films of 1-3 showed luminescence at 378, 485 and 510 nm, respectively. All of these boron compounds were sublimable under vacuum condition of 1.7 × 10−5 Torr. Further studies on these compounds have been attempted in our laboratory for the photoelectronic applications such as light-emitting layers of the light-emitting devices.