Oxazine dyes act as reporters of their near environment by the response of their fluorescence spectra. At the same time, their fluorescence spectra exhibit a pronounced vibrational progression. In this work, we computationally investigate the impact of near-environment models consisting of aggregated water as well as betaine molecules on the vibrational profile of fluorescence spectra of different oxazine derivatives. For aggregated betaine and a water molecule located above the plane of the dyes, we observe a distinct modification of the vibrational profile, which is more pronounced than the effect of a continuum description of a solvent environment. Our analysis shows that this effect cannot be explained by a pure change in the electronic structure, but that also vibrational degrees of freedom of the environment can be decisive for the vibrational profile and should, hence, not generally be neglected.

中文翻译：

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微环境对计算振动分辨发射光谱的作用：以恶嗪为例


恶嗪染料通过其荧光光谱的响应充当其附近环境的报告者。同时，它们的荧光光谱表现出明显的振动级数。在这项工作中，我们通过计算研究了由聚集水和甜菜碱分子组成的近环境模型对不同恶嗪衍生物荧光光谱振动轮廓的影响。对于聚集的甜菜碱和位于染料平面上方的水分子，我们观察到振动轮廓的明显改变，这比溶剂环境的连续描述的效果更明显。我们的分析表明，这种效应不能用电子结构的纯粹变化来解释，但环境的振动自由度对于振动轮廓也具有决定性作用，因此通常不应被忽视。