Work

Unsymmetrical naphthalene diimides as electrochromic materials: tailoring structure for controlled optical and redox properties

Year: 2026

Type: article

Abstract: -substituents with progressively increasing electron-donating ability, enabling systematic tuning of their electrochemical and optical properties. All compounds exhibit two reversible reduction processes, whereas donor-functionalized derivatives additionally undergo reversible oxidation, resulting in multistate electrochromism. Spectroelectrochemical studies reveal three, four, and five distinct optical states for NDI-1, NDI-2, and NDI-3, respectively, accompanied by pronounced absorption changes across the visible and near-infrared regions. Owing to its broad electrochemical window and rich optical response, NDI-3 was employed as the active material in a solid-state electrochromic device, which demonstrated reversible multicolor switching, optical modulation in the visible and near-infrared regions, switching times of 1.4-8.7 s, with particularly good stability observed for the radical anion/dication transition. These findings demonstrate that molecular engineering of unsymmetrical NDI derivatives provides an effective strategy for developing multistate electrochromic materials with tunable optical properties for advanced electrochromic devices and energy-efficient smart window applications.

Source: RSC Advances

DOI: 10.1039/d6ra08357a

Authors: Marcin Nowacki, Sergiusz Napierała, Monika Wałęsa-Chorab

Institution: Adam Mickiewicz University in Poznań

Language: English

Topic: Conducting polymers and applications

Subfield: Polymers and Plastics

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,042

Funders: Narodowe Centrum Nauki, Narodowym Centrum Nauki