No abstract

Three solution-processable D-A-type conjugated polymers P1, P2 and P3 were successfully synthesized via the Pd-catalyzed Stille cross-coupling copolymerization approach, with 6,8-Dibromo-3,3-bis-decyl-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepine (M1) and 2,5-Bis(trimethylstannanyl)thiophene (M3) as the donor units and 4,7-Dibromo-5,6-difluoro-2-(2-hexyl-decyl)-2H-benzotriazole (M2) as the acceptor unit, wherein the feed ratio of the three units was 1:3:4 (M1:M2:M3, the same below), 1:1:2 and 3:1:4 for P1, P2, and P3, respectively. The results obtained by our test showed that the feed ratio between the D and A units had a significant effect on both the electrochemical and the spectroelectrochemical properties of the three polymers. The copolymers exhibited a gradually deepening red color in neutral state with the increase of M1 content and then turned to a transmissive grey color in the oxidation state. Also, three copolymers showed good performance in electrochromic parameters, which mainly consists of optical contrast, response time, and coloration efficiency. In general, the excellent electrochromic performances of the copolymers make them outstanding candidates for electrochromic material applications.

This paper explores high-contrast mechanoresponsive luminescence (MRL) turn-on materials by combining the features of the coumarin and typical aggregationinduced emission enhancement (AIEE) tetraphenyethylene groups. Therefore, fluorogen C3Ph is obtained by fusing triphenylvinyl and coumarin units, which exhibits typical AIEE characteristics with high solid-state photoluminance (PL) efficiency in the amorphous state. The formation of a unique two-dimensional hydrogen-bonded organic framework (HOF) is responsible for the crystalline-state PL quenching but guarantees the luminescence turn-on to the external stimuli. Furthermore, the reversible solid-state fluorescence on−off cycle for C3Ph can be achieved by alternate grinding and melting−solidifying. This work also offers a way to construct high-contrast MRL turn-on materials by using the HOFinvolved molecules.

A series of trinuclear lanthanide circular helicates [Ln3L3]Cl3 have been synthesized via supramolecular subcomponent self-assembly. Photophysical studies demonstrate that the unique helical bis-tetradentate 1,29-dialdehyde ligand L2- could serve as an...