New Acceptor-Donor-Acceptor Systems Based on Bis-(Imino-1,8-Naphthalimide)

Materials (Basel). 2021 May 21;14(11):2714. doi: 10.3390/ma14112714.

Abstract

In this paper, six novel symmetrical bis-(imino-1,8-naphthalimides) differing in core and N-substituent structure were synthesized, and their thermal (TGA, DSC), optical (UV-Vis, PL), electrochemical (DPV, CV) properties were evaluated. The compounds were stable to 280 °C and could be transferred into amorphous materials. Electrochemical investigations showed their ability to occur reductions and oxidations processes. They exhibited deep LUMO levels of about -3.22 eV and HOMO levels above -5.80 eV. The optical investigations were carried out in the solutions (polar and non-polar) and in films and blends with PVK:PBD. Bis-(imino-1,8-naphthalimides) absorbed electromagnetic radiation in the range of 243-415 nm and emitted light from blue to yellow. Their capacity for light emission under voltage was preliminarily tested in devices with an active layer consisting of a neat compound and a blend with PVK:PBD. The diodes emitted green or red light.

Keywords: 1,8-naphthalimides; C-3 position; azomethinediimides; electrochemistry; luminescence.