Photochemistry Center of the Russian Academy of Sciences, Moscow, Russia.
J Phys Chem A. 2011 May 5;115(17):4505-10. doi: 10.1021/jp1123579. Epub 2011 Apr 6.
The photophysical properties of aqueous solution of styryl dye, 4-[(E)-2-(3,4-dimethoxyphenyl)ethenyl]-1-ethylpyridinium perchlorate (dye 1), in the presence of cucurbit[7]uril (CB[7]) was studied by means of fluorescence spectroscopy methods. The production of 1:1 host-guest complexes in the range of CB[7] concentrations up to 16 μM with K = 1.0 × 10(6) M(-1) has been observed, which corresponds to appearance of the isosbestic point at 396 nm in the absorption spectra and a 5-fold increase in fluorescence intensity. The decay of fluorescence was found to fit to double-exponential functions in all cases; the calculated average fluorescence lifetime increases from 145 to 352 ps upon the addition of CB[7]. Rotational relaxation times of dye 1 solutions 119 ± 14 ps without CB[7] and 277 ± 35 ps in the presence of CB[7] have been determined by anisotropy fluorescence method. The comparison of the results of quantum-chemical calculations and experimental data confirms that in the host cavity dye 1 rotates as a whole with CB[7].
研究了在葫芦[7]脲（CB[7]）存在下，苯乙烯染料 4-[(E)-2-(3,4-二甲氧基苯基)乙烯基]-1-乙基吡啶翁高氯酸盐（染料 1）在水溶液中的光物理性质。在 CB[7]浓度范围内至 16 μM 的范围内观察到 1:1 主客体配合物的生成，K = 1.0×10(6) M(-1)，这对应于吸收光谱中在 396nm 处出现等色点和荧光强度增加 5 倍。在所有情况下，荧光衰减都被发现符合双指数函数；加入 CB[7]后，计算得到的平均荧光寿命从 145ps 增加到 352ps。通过各向异性荧光法测定了无 CB[7]时染料 1 溶液的旋转弛豫时间为 119±14ps，而有 CB[7]时为 277±35ps。量子化学计算结果与实验数据的比较证实，在主体空腔中，染料 1 与 CB[7]整体旋转。
