In this work, a new crystalline polyoxometalate-viologen hybrid, (Pbpy)(Me2NH2)3[PW11ZnO40] (1: Pbpy = 1,1'-[1,4-phenylenebis-(methylene)]bis(4,4'-bipyridinium)), has been synthesized. It showed efficient ultraviolet light detection ability with an obvious colour change from pale yellow to blue and fast response with ultraviolet intensity as low as 0.006 mW cm-2 in narrow-band UV regions. The POM-viologen-based film of 1 has also been readily prepared on quartz substrates using a drop casting method and could exhibit different levels of colour changes under sunlight irradiation at different local times on a sunny day, indicating its potential to be used as a portable device for solar ultraviolet light detection. Ultraviolet light detection is not only reflected in colour changes, but also accompanies the photoluminescence phenomenon. The fluorescence intensity decreased with the increase of UV intensity, and when irradiated with an ultraviolet xenon lamp (8 mW cm-2) for about 5 min, the fluorescence intensity was almost completely quenched. The compound has the potential to achieve fluorescence based UV probing. The powdered sample of compound 1 could also be deposited in paper simply by coating it with a solution of ethanol. The paper can be used as an inkless and erasable print medium, which was found to remain clear for 11 d in the dark under an ambient atmosphere and was also reusable when erased.

中文翻译：

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多金属氧酸盐-紫罗兰色光致变色杂化物，用于快速检测太阳紫外线，基于光致发光的紫外线探测以及无墨和可擦除的打印。

在这项工作中，一个新的结晶多金属氧酸盐-紫罗兰杂化物，（Pbpy）（Me2NH2）3 [PW11ZnO40]（1：Pbpy = 1,1'-[1,4-亚苯基双-（亚甲基）] bis（4,4'- bipyridinium）），已经合成。它显示出有效的紫外光检测能力，从浅黄色到蓝色具有明显的颜色变化，并且在窄带UV区中的紫外强度低至0.006 mW cm-2时具有快速响应。1的POM-紫罗兰色基膜也很容易使用滴铸法在石英基板上制备，并且在晴天在阳光照射下的不同局部时间可能表现出不同水平的颜色变化，表明其潜在的用途用于太阳紫外线检测的便携式设备。紫外光检测不仅反映在颜色变化中，还伴随着光致发光现象。荧光强度随着紫外线强度的增加而降低，并且当用紫外线氙灯（8 mW cm-2）照射约5分钟时，荧光强度几乎被完全淬灭。该化合物具有实现基于荧光的紫外线探测的潜力。化合物1的粉末状样品也可以简单地通过用乙醇溶液涂布而沉积在纸上。该纸可用作无墨水和可擦除的打印介质，发现该介质在黑暗中于环境气氛下保持透明11 d，并且在擦除后也可以重复使用。化合物1的粉末状样品也可以简单地通过用乙醇溶液涂布而沉积在纸上。该纸可用作无墨水和可擦除的打印介质，发现该介质在黑暗中于环境气氛下保持透明11 d，并且在擦除后也可以重复使用。化合物1的粉末状样品也可以简单地通过用乙醇溶液涂布而沉积在纸上。该纸可用作无墨水和可擦除的打印介质，发现该介质在黑暗中于环境气氛下保持透明11 d，并且在擦除后也可以重复使用。