Conjugated polymers complexed with helical porphyrin oligomers create micron-sized ordered structures.
Conjugated polymers complexed with helical porphyrin oligomers create micron-sized ordered structures.
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DOI：
10.1002/anie.200601493
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发表时间：
2006-08
影响因子：
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通讯作者：
M. Takeuchi;Chiaki Fujikoshi;Yohei Kubo;K. Kaneko;S. Shinkai
中科院分区：
文献类型：
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作者：
M. Takeuchi;Chiaki Fujikoshi;Yohei Kubo;K. Kaneko;S. Shinkai
5495 Angew. Chem. Int. Ed. 2006, 45, 5494–5499 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www. angewandte. org at λex= 400 nm (an isosbestic point in the UV/Vis spectrum) at 258C, we observed that the emission intensity (λem= 465 nm) of CP1 decreased upon increasing the Por-12 concentration (Figure 1b). At [Por-12]= 0.072 mm, the fluorescence intensity of CP1 decreased to 7% of its value in the absence of Por-12. This finding clearly indicates that the Por-12 and CP1 units interact and that efficient energy transfer from CP1 to Por-12 probably occurs in their complex as a result of the emission wavelength of CP1 overlapping considerably with the absorption band of Por-12. We obtained a solution-cast film after deposition of a homogeneous solution of CP1 (0.30 mm unit) in CDCl3 containing 5.0 wt% polystyrene (Mw= 200000) on a quartz plate. The emission spectrum of this CP1 film was broad in comparison with that recorded in dilute solution ([CP1 unit]= 0.03 mm). This effect probably is due to random aggregation of the polymer main chains in the film.[15] Interestingly, the addition of Por-12 transformed the broad emission obtained in the solid state into the sharp one similar to that observed for a dilute solution of CP1 (see the Supporting Information), that is, random aggregates of CP no longer exist. With this experiment, we also confirmed the bathochromic shift of the Q bands of Por-12 in the solid state, thus indicating that Por-12 formed the complex with CP1 (see the Supporting Information). The UV/Vis and emission spectra of the solution-cast film of the composite formed between Por-12 and CP1 in CDCl3 suggest that the structure of the composite is maintained in the solid state.To obtain visual images, we examined the composite formed between Por-12 and CP1 in CDCl3 using confocal laser scan microscopy (CLSM), polarized optical microscopy (POM), and high-resolution transmission electron microscopy(HRTEM). From the HRTEM image, we confirmed that the Por-12/CP1 composites grew into large aggregates (several microns in size) that possess stacked sheetlike 2D structures (see below). In a separate study, we confirmed that the aggregates of Por-12 or CP1 alone are amorphous [15] and cannot organize into 2D structures as large as that presented in Figures 2 and 3.
