Persistent optical hole-burning spectroscopy has been conducted for a dye molecule within a very small (∼1 nm) reverse micelle at room temperature. The spectra show a spectral narrowing due to site-selective excitation. This definitely demonstrates that the surroundings of the dye molecule are in a glassy state regardless of a solution at room temperature. On the other hand, the hole-burning spectra exhibit large shifts from excitation frequencies, and their positions are almost independent of excitation frequencies. The hole-burning spectra have been theoretically calculated by taking account of a vibronic absorption band of the dye molecule under the assumption that the surroundings of the dye molecule are in a glassy state. The calculated results agree with the experimental ones that were obtained for the dye molecule in a polymer glass for comparison, where it has been found that the ratio of hole-burning efficiencies of vibronic- to electronic-band excitations is quite high. On the other hand, the theoretical results do not explain the large spectral shift from the excitation frequency and small spectral narrowing observed in the hole-burning spectra measured for the dye-containing reverse micelle. It is thought that the spectral shift and broadening occur within the measurement time owing to the relaxation process of the surroundings that are hot with the thermal energy deposited by the dye molecule optically excited. Furthermore, the relaxation should be temporary because the cooling of the inside of the reverse micelle takes place with the dissipation of the excess thermal energy to the outer oil solvent, and so the surroundings of the dye molecule return to the glassy state and do not attain the thermal equilibrium. These results suggest that a very small reverse micelle provides a unique reaction field in which the diffusional motion can be controlled by light in a glassy state.

中文翻译：

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室温下液体中纳米约束染料分子的持久光洞燃烧光谱：由于玻璃态和纳米笼中的异常弛豫导致光谱变窄

在室温下，已经对非常小的（〜1 nm）反胶束中的染料分子进行了持久光洞燃烧光谱分析。光谱显示由于位点选择性激发而使光谱变窄。这无疑表明染料分子的周围环境呈玻璃态，而与室温下的溶液无关。另一方面，空穴燃烧光谱显示出与激发频率的较大偏移，并且它们的位置几乎与激发频率无关。在假定染料分子周围处于玻璃态的假设下，通过考虑染料分子的振动吸收带，从理论上计算出了空穴燃烧光谱。计算结果与在聚合物玻璃中用于比较的染料分子的实验结果相符，在该实验中发现，电子束和激发带的空穴燃烧效率之比非常高。另一方面，理论结果不能解释由激发频率引起的大光谱偏移和在对含染料的反胶束测得的空穴燃烧光谱中观察到的光谱狭窄。可以认为，由于周围环境的松弛过程，利用由光学激发的染料分子沉积的热能使周围环境变热，因此在测量时间内发生了光谱偏移和展宽。此外，松弛应该是暂时的，因为反向胶束内部的冷却是随着多余的热能消散到外部油溶剂中而发生的，因此染料分子的周围环境返回到玻璃态而没有达到热态。平衡。这些结果表明，非常小的反胶束提供了独特的反应场，在该反应场中，扩散运动可以由玻璃态的光控制。