吉林大学杨柏研究团队报道了近红外室温磷光自保护碳化聚合物点的交联增强发光主导设计策略。相关研究成果发表在2024年8月7日出版的《德国应用化学》。

具有有利交联纳米结构的自保护碳化聚合物点（CPDs）在无金属室温磷光（RTP）材料中引起了相当大的关注，然而，它们的RTP发光仍然局限于短波长。将它们的RTP发光扩展到近红外（NIR）范围是有吸引力的，但在构建窄能级和抑制强烈的非辐射衰变方面存在困难。

该文提出了一种以交联增强发射（CEE）为主的构建策略，首次在自保护CPDs中实现了所需的近红外RTP（710 nm）发光。结构因素，即交联（共价键CEE）、共轭（具有桥接N-H和C=C基团的共轭胺）和空间位阻（受限域CEE），被证实是触发CPDs中NIR RTP发光不可或缺的。对比实验和理论计算进一步揭示了源自CEE的设计策略在促进三重态激子窄能级发射和抑制非辐射猝灭方面的合理性。

该项工作不仅首次在自保护CPDs中实现了NIR RTP，而且有助于了解NIR RTP的起源，以进一步指导具有高效长波RTP发光的各种CPDs的合成。

附：英文原文

Title: Crosslink-Enhanced Emission-Dominated Design Strategy for Constructing Self-Protective Carbonized Polymer Dots with Near-Infrared Room-Temperature Phosphorescence

Author: Chengyu Zheng, Songyuan Tao, Xinxiang Zhao, Chunyuan Kang, Bai Yang

Issue&Volume: 2024-08-07

Abstract: Self-protective carbonized polymer dots (CPDs) with advantageous crosslinked nano-structures have attracted considerable attention in metal-free room temperature phosphorescence (RTP) materials, whereas, their RTP emissions are still limited to short wavelength. Expanding their RTP emission to Near-Infrared (NIR) range is attractive but suffers from the difficulties in constructing narrow energy levels and inhibiting intense nonradiative decay. Herein, a crosslink-enhanced emission (CEE)-dominated construction strategy was proposed, achieving desired NIR RTP (710 nm) in self-protective CPDs for the first time. Structural factors, i.e.，crosslinking (covalent-bond CEE), conjugation (conjugated amine with bridging N-H and C=C group), and steric hindrance (confined-domain CEE), were confirmed indispensable for triggering NIR RTP emission in CPDs. Contrast experiments and theoretical calculations further revealed the rationality of the design strategy originating from CEE in terms of promoting the narrow energy level emission of triplet excitons and inhibiting the nonradiative quenching. This work not only firstly achieves NIR RTP in self-protective CPDs, but also helps understand the NIR RTP origin to further guide the synthesis of diverse CPDs with efficient long-wavelength RTP emission.

DOI: 10.1002/anie.202408516

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202408516