When designing photoresponsive materials, the impact of a polymer host matrix on the photophysical and photochemical properties of chromophores can be dramatic and advantageous for correlating macromolecular properties. Some compounds possess changes in their photophysical response with variation in the surrounding media (e.g., crystalline glass vs solution). This study demonstrates how changes in the excited state dynamics of [Cu(dmp)₂]⁺, where dmp = 2,9-dimethyl-1,10-phenanthroline, are used to quantitatively probe the viscosity of the surrounding polymer matrix. A correlation of both excited state lifetime and photoluminescence emission wavelength on viscosity was observed in different supramolecular materials containing [Cu(dmp)₂]⁺. These effects were attributed to restricted photoinduced structural distortion of the Cu(I) complex as the polymer matrix hardened. This photoluminescence sensor features a greater dynamic range for viscosity sensing (6 orders of magnitude) and displayed larger changes in lifetime response with respect to typical organometallic mechanosensitive probes.

中文翻译：

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用于传感机械性能的 Cu(I) 配合物的受限光致构象变化

在设计光响应材料时，聚合物主体基质对发色团的光物理和光化学性质的影响可能是巨大的，并且对于关联大分子性质是有利的。一些化合物的光物理响应随周围介质的变化而变化（例如，结晶玻璃与溶液）。这项研究展示了 [Cu(dmp) ₂ ] ⁺的激发态动力学的变化，其中 dmp = 2,9-二甲基-1,10-菲咯啉，如何用于定量探测周围聚合物基质的粘度。在含有 [Cu(dmp) ₂ ] ^{+的不同超分子材料中观察到激发态寿命和光致发光发射波长与粘度的相关性}. 这些影响归因于当聚合物基体硬化时，Cu(I) 配合物的光致结构变形受到限制。这种光致发光传感器具有更大的粘度传感动态范围（6 个数量级），并且相对于典型的有机金属机械敏感探针，其寿命响应变化更大。