Complex Photophysical Behaviors Affect Single Conjugated Molecule Optical Anisotropy Measurements
Complex Photophysical Behaviors Affect Single Conjugated Molecule Optical Anisotropy Measurements
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DOI：
10.1021/acs.jpcc.8b10916
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发表时间：
2019-01
影响因子：
3.7
通讯作者：
Heungman Park;Heungman Park;Youngah Kwon;L. Kaufman
中科院分区：
文献类型：
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作者：
Heungman Park;Heungman Park;Youngah Kwon;L. Kaufman
偏振调制深度 (M) 测量已被广泛用作报告过渡偶极子排列以及单个共轭聚合物和聚集体的分子构象的技术。然而，由于光物理过程（其本身与构象耦合）可能影响 M 值，因此从这些测量中推断构象变得复杂。在这里，我们证明强度依赖的部分光致发光猝灭的存在可以抑制 M 值，这种抑制在具有高度对齐的过渡偶极子的分子中更为突出。我们表明，这些关于 M 值的发现是荧光强度最大值和最小值行为作为聚[2-甲氧基-5-(2-乙基己氧基)-1,4-亚苯基亚乙烯基]单分子中激发偏振的函数的直接结果，并得到重现实验结果的模拟的支持。我们的研究结果表明，用复杂的光物理学解释分子的 M 值应该用......
Polarization modulation depth (M) measurements have been widely used as a technique to report on transition dipole alignment and thus molecular conformation of single conjugated polymers and aggregates. Such extrapolation of conformation from these measurements, however, is complicated by the fact that photophysical processes (which themselves are coupled to conformation) may influence M values. Here, we show that the presence of intensity-dependent partial photoluminescence quenching can suppress M values, with this suppression more prominent in molecules with highly aligned transition dipoles. We show that these findings on M values are a direct consequence of behaviors of fluorescence intensity maxima and minima as a function of excitation polarization in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] single molecules, as supported by a simulation that reproduces the experimental results. Our findings show that interpreting M values of molecules with complex photophysics should be done with ...