Organic room temperature phosphorescence (RTP) materials have garnered significant interest owing to their unique photophysical properties and promising applications, whereas most of them are sensitive to solvents. Enhancing their resistance to solvents is attractive but suffers from severe deactivation of triplet excitons especially in polar solvents. Herein, we propose a self-sorting co-assembly strategy to achieve ultralong liquid-phase RTP with multicolor fluorescence. The fluorophores containing N-heteroatoms and hydrogen bonding acceptors/donors co-assemble with melamine (MA) and cyanuric acid (CA) to offer ultralong liquid-phase RTP emission with a lifetime of up to 544 ms in water. In addition, the organic phosphors can be employed as chelating ligands to coordinate lanthanide ions, endowing liquid-phase RTP with multicolor fluorescence and remaining excellent resistance to various polar and nonpolar solvents. Relying on robust liquid-phase RTP emission and intense multicolor fluorescence, dual-modality visual detection of leakage is demonstrated as a proof-of-concept. This study provides a reliable avenue for realizing ultralong liquid-phase RTP with multicolor fluorescence to meet versatile uses.
Kaiyi Zhou,Hui Cao,Pan Gao,Zhigang Cui,Yi Ding,Yuanli Cai
Autocatalytic self-sorting in the biomimetic poly(cystamine methacrylamide hydrochloride) (PCysMA) is presented, whose units comprise lysine-mimetic alkylammonium ions and cystine-mimetic alkyl disulfide spacers. The block copolymer with poly(2-hydroxypropylmethacrylamide) was synthesized directly by RAFT in acidic water under visible light irradiation at 25 °C. Disulfide exchange can be initiated by the terminal thiolates as generated by alkalization-induced aminolysis. 65–67% CysMA units sort into hydrophobic polymer disulfides and water-soluble cystamine at pH 10.5. Moreover, intermediate reactions occur in the presence of copper ions, i.e., Cu(II)–NH2 coordination, aminolysis, NH2-to-SH substitution, and cupric-to-cuprous reduction in metal centers, thus autocatalytic self-sorting with essentially 100% conversion at pH 8.8. UV–vis spectroscopy, 1H NMR, atomic absorption spectroscopy, and elemental analysis confirmed this ideal self-sorting. Dynamic light scattering and atomic force microscopy identified supramolecular-to-supracolloidal self-assembly with concomitant release of cystamine molecules and intermediate cuprous complexes. Such a self-sorting underlines an amazing prospect for the use of a single polymer to achieve artificial reaction complexity, hierarchy, and metabolic process, with minimal synthetic efforts.
Xinlin Zha,Guilin Xu,Yi Xiong,Zhong Yan,Ke Liu,Mufang Li,Yuanli Chen,Jing Lu,Dong Wang
Designing artificial systems to mimic chiral superstructures and exploring how achiral molecules precisely modulate their chirality is crucial to understand the origin of homochirality in nature. Herein, the tunability nature of supramolecular chirality is subtly applied to fabricate robust chiral covalent polymers with controlled macroscopic helicity. When using conventional supramolecular transcription methods to prepare chiral poly(m-phenylenediamine), simply introducing various small amounts of achiral diaminopyridines (DAPs) to copolymerize with m-phenylenediamine (MPD) enables the resulting chiral copolymers with adjustable helical configurations and chiroptical activities in an enantiopure template system. The strong hydrogen bonds between DAPs and the template molecules (( S )/( R )-PhgC 16 ) proved to be the driving force for guiding the chiral polymerization mode of MPD. Impressively, the exquisite self-sorting phenomenon is observed by tuning the stoichiometric ratio of DAP and ( R )-PhgC 16 , where the as-prepared copolymers with opposite helicity can exist simultaneously to form a double network structure and their chiroptical activity can be well regulated. In addition, based on such a copolymerization strategy, a conceptual library of helical functional copolymers is built with editable polymer types including conducting polymers and designable amine-aldehyde condensation-based polymers. This copolymerization-mediated synthetic strategy may facilitate the development of chiral polymers with controlled morphologies and dynamic compositions.
危险品化学品经营许可证（带存储）