State Key Laboratory of Superhard Materials, Synergetic Extreme Condition High-Pressure Science Center, College of Physics, Jilin University, 130012, Changchun, China.
Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
Adv Mater. 2023 Jun;35(23):e2211729. doi: 10.1002/adma.202211729. Epub 2023 Apr 25.
As equally essential as the synthesis of new materials, maneuvering new structure configurations can endow the brand-new functional properties to existing materials, which is also one of the core goals in the synthesis community. In this respect, pressure-induced emission (PIE) that triggers photoluminescence (PL) in nonemission materials is an emerging stimuli-responsive smart materials technology. In the PIE paradigms, harvesting bright PL at ambient conditions, however, has remained elusive. Herein, a remarkable PIE phenomenon is reported in initially nonemission Zn(BDC)(DMF)(H O) (MOF-2), which shows bright blue-emission at 455 nm under pressure. Intriguingly, the bright blue PL with an excellent photoluminescence quantum yield up to 70.4% is unprecedentedly retained to ambient conditions upon decompression from 16.2 GPa. The detailed structural analyses combined with density functional theory calculations reveal that hydrogen bonding cooperativity effect elevates powerfully the rotational barrier of the linker rotor to 3.87 eV mol from initial 0.91 eV mol through pressure treatment. The downgrade rotational freedom turns on PL of MOF-2 after releasing pressure completely. This is the first case of harvesting PIE to ambient conditions. These findings offer a new platform for the creation of promising alternatives to high-performance PL materials based on initially nonemission counterparts.
与新材料的合成同等重要的是，操纵新的结构构型可以赋予现有材料全新的功能特性，这也是合成界的核心目标之一。在这方面，压力诱导发射（PIE）在非发射材料中触发光致发光（PL）是一种新兴的刺激响应智能材料技术。在 PIE 范例中，在环境条件下收集明亮的 PL 仍然难以实现。在此，首次报道了初始非发射 Zn(BDC)(DMF)(H 2 O)（MOF-2）中的显著 PIE 现象，该现象在 16.2 GPa 的压力下显示出 455nm 的明亮蓝光发射。有趣的是，在从 16.2 GPa 减压时，其明亮的蓝光发射具有高达 70.4%的出色光致发光量子产率，这是前所未有的，可在环境条件下保留下来。详细的结构分析结合密度泛函理论计算表明，氢键协同效应通过压力处理将连接体转子的旋转势垒从初始的 0.91 eV/mol 强力提升至 3.87 eV/mol。在完全释放压力后，降级的旋转自由度开启了 MOF-2 的 PL。这是首例在环境条件下收获 PIE 的案例。这些发现为基于初始非发射对应物的高性能 PL 材料提供了一个有前途的替代方案的新平台。
