The synthesis of organic electron-transport materials (ETMs) for organic light-emitting diodes (OLEDs) has been intensely pursued. Herein we report an organic phosphinyl compound (2,2′-Binaphthyl-6,6′-diyl)bis(diphenylphosphine oxide) ( BiNa-BiDPO ) with concise synthesis and purification. BiNa-BiDPO is thermally stable up to ca. 415 °C and exhibits distinct glass transition with a T g of 112 °C after being cooled from the melt. Upon further heating, no crystallization or melting is observed. Ultraviolet photoemission spectroscopy studies reveal that E HOMO ≈ −6.12 eV for the new compound. Consequently, the LUMO level was roughly estimated as −2.77 eV based on the onset of the film absorption spectrum. BiNa-BiDPO possesses a higher electron mobility of 1.6–8.4 × 10 −5 cm 2 V −1 s −1 at E = 2–5 × 10 5 V cm −1 , relative to a common ETM 1,3,5-tris( N -phenylbenzimidazolyl)benzene ( TPBi ), thus providing better OLED efficiency with lower working voltage. Moreover the OLED devices involving BiNa-BiDPO as the electron-transport layer showed a half life-time of 172 h at an initial luminance of ca. 1000 cd m −2 , driven at a constant current density, in contrast with the TPBi device with a shortened t 1/2 of 93 h. Further device engineering as well as molecular design may provide enhanced device durability. [ABSTRACT FROM AUTHOR]