Long persistent luminescence (LPL) materials have been fascinating from ancient times till today, whereas the generation and modulation of LPL are still uncontrollable in most cases. In this paper, a smart responsive metal–organic framework (MOF, LIFM-WZ-1) was reported to combine resilient structural dynamics with reversible LPL modulation. At room temperature in air, the as-prepared LIFM-WZ-1 has a staggered packing structure with inhaled water molecules between cavities, exhibiting fluorescence (F)-dominated blue emission. Under vacuum or by mild heating, the water molecules can be exhaled by the lattice, resulting in a crystal structure (LIFM-WZ-1a) with a reduced a axis and intensified intermolecular interactions. This brings transition to green excimer (E) emission related with lowered energy states. Meanwhile, orange-colored room temperature phosphorescence (RTP) is also enhanced, giving an overall balanced F/E/RTP emission. More fascinatingly, red LPL is ignited in the dehydrated sample, which is dumb in the original LIFM-WZ-1 because of intensified singlet to triplet intersystem crossing, damped high-energy oscillation, and compatible heat dissipation. The above breathing-induced LPL turn-on process is reversible by facile cooling, exposing to wet air, or purging in water vapor. This constitutes a successful exemplification in modulating LPL by the dynamic MOF, which provides potential applications in sensing, anti-counterfeiting, display, and so on.

中文翻译：

---

弹性金属-有机框架中的呼吸激发长持续发光

从远古时代到今天，长期持续发光（LPL）材料一直着迷，而在大多数情况下，LPL的生成和调制仍然不可控。在本文中，据报道，智能响应金属-有机框架（MOF，LIFM-WZ-1）将弹性结构动力学与可逆LPL调制相结合。在室温下的空气中，所制备的LIFM-WZ-1具有交错的堆积结构，在腔之间具有吸入的水分子，表现出以荧光（F）为主的蓝色发射。在真空或温和加热下，水分子可被晶格呼出，从而导致晶体结构（LIFM-WZ-1a）具有降低的轴和加剧的分子间相互作用。这带来了与能量状态降低相关的绿色准分子（E）发射的过渡。同时，还增强了橙色的室温磷光（RTP），使F / E / RTP发射总体平衡。更令人着迷的是，脱水的样品中会点燃红色的LPL，这在原始LIFM-WZ-1中是愚蠢的，这是因为单重态到三重态的系统间交叉增强，阻尼的高能振荡和兼容的散热。上述呼吸诱导的LPL开启过程可以通过轻松冷却，暴露于湿空气或吹扫水蒸气来逆转。这构成了动态MOF调制LPL的成功范例，它在传感，防伪，显示等方面提供了潜在的应用。