Ammonia sensing properties of perylene diimides: Effects of core-substituted chiral groups

- New chiral perylenediimide derivatives (PDIs) conductometric sensors were prepared.
- These PDIs sensors showed high sensitivity，excellent selectivity and low detection limit to ammonia vapor.
- Experimental results suggested that chiral alkyl chain had significant effect on the sensing performance of PDIs devices.

The detection of ammonia vapor has strong implications for health, safety and environment. Herein, we reported on an high efficient chemiresistive sensor based on perylenediimide derivatives (PDIs) substituted by (S)-1-octyn-3-ol (SOT), (S)-3-butyn-2-ol (STB) and (S)-1-phenyl-2-propyn-1-ol (SPP) on 1, 7- bay positions. These PDIs devices exhibited high sensitivity, excellent selectivity and low detection limit towards ammonia vapor. In these materials, SPP showed the most efficient sensing performance, and the increment of current is 4 and 1.2 orders of magnitude higher than SOT and STB due to its lowest LUMO energy, uniform and continuous crystalline phase with π-π stacking distance of 3.28 Å. While the highest LUMO energy, poor crystallinity, and smaller π-π overlap as well as largest π-π distance of 3.35 Å resulted in the lowest performance of SOT device. It is expected that excellent sensing parameters and detailed analysis of the roles of core-substituted chiral groups will provide a basis protocol for the design of simple, low-power and high efficient PDIs sensors.