| 研究実績の概要 |
This research project in this year is originated from a serendipitous discovery. A topological defect-directed nucleation and growth of a porphyrin-based core-shell-like microstructure (PorMOF) is discovered with the aid of in situ optical microscopic observations. The key points are summarized as follows:
1.A unique crystallization pathway of a porphyrin-based crystalline microstructure with a core-shell morphology is discovered in one-pot synthesis of zinc nitrate hexahydrate, 4,4’-azopyridine (AzoPy) and 4,4’,4’’,4’’’-(porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) (2HPor) in DMF / EtOH (v / v = 3:1) in a quartz cell (1 mm × 10 mm) at 64°C.
2.The morphologies and structures of this crystalline microstructure are characterized by scanning electron microscopy, transmission electron microscopy and atomic force microscopy and X-ray diffraction analysis.
3.The mechanism of this crystalline microstructure formation is established based on in situ optical microscopic observations that a topological defects pinned at the center of shell crystals directs and triggers the nucleation and growth of a new crystalline phase because of a lower energy barrier.
4.Such a crystalline microstructure exhibits unique photophysical properties that the shell part imposes a remarkable impact on the fluorescence emission of the corresponding core part that locates in the center of the shell. More specifically, the shell can quench the fluorescence of the core; and if the core crystal is released from the shell part, anisotropic fluorescence emission is observed.
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