Charge transfer emission from 1,4,5,8-naphthalimide-polystyrene

Abstract The photoluminescence (PL) of powders consisting of N,N′-(N,N′-dimethylethyleneamine-N″-allyl) – 1,4,5,8-naphthaldiimide (ANDI) and polystyrene (PS) was studied as they are simply ground together and as repetitive units of copolymers. Reflectance absorption spectra showed typical solid-state ANDI CT-band from 430 nm until 600 nm by both the mixture and the copolymers. PL of the copolymers was proposed to be a CT-emission that comes from the electron donor–acceptor styrene-NDI interaction. Under excitation at 365 nm, the copolymers exhibited emission, λmax ~ 500 nm, with intensity inversely proportional to the ANDI amount. The PS-ANDI ground powders displayed an excimer-like emission band at ca. 485 nm, inversely, increasing ANDI amount in the mix, PL increases. XRD analysis showed that the ANDI crystals were dismantled in some extent inside the PS matrix as they were ground together. An easy method was developed to obtain an emitting-solid system that can be useful to generate charge-transfer devices.