取代基对卟啉分子自组装聚集体纳米结构的调节

摘要

Metal free tetrakis (4-methoxylphenyl) porphyrin ( Ⅰ ), tetra ( phenyl ) porphyrin ( Ⅱ ) and tetrakis (4-chlorophenyl) porphyrin ( Ⅲ ) were assembled into organic nanostructures by "one-step" method.Their self-assembly properties,especially the effect of meso-substituents with varied electron-donating/withdrawing properties on tuning and controlling the morphology of self-assembled nanostructures of these porphyrin derivatives, have been comparatively studied by electronic absorption, transmission electronic microscopy (TEM) ,and X-ray diffraction(XRD) techniques.J-type aggregates have been formed with the increasing degree of intermolecular interaction (Ⅲ ) ＜ ( Ⅱ ) ＜ ( Ⅰ ), which are in agreement with the degree of electron-donating and electron-withdrawing properties of mesosubstituents.TEM observation suggests that the microcrystal structure is dependent on the degree of intermolecular interaction resulting from varied meso-substituents of these porphyrin derivatives.Square and lamellar, nanorods as well as nanobelts structures have been obtained in aggregates of porphyrin ( Ⅰ ), ( Ⅱ ), ( Ⅱ ), respectively.Favorable growing direction of microstructures in these aggregates is different in the self-assembly process,which in turn result in different morphology for the self-assembled nanostructures.%运用简单的"one-step"法自组装技术,将Meso位具有不同取代基团的卟啉分子Meso-5, 10, 15, 20-四(对甲氧基苯基)卟啉(Ⅰ), Meso-5, 10, 15, 20-四苯基卟啉(Ⅱ)和Meso-5, 10, 15, 20-四(对氯苯基)卟啉(Ⅲ)组装成有机纳米聚集体.利用多种表征手段系统研究化合物(Ⅰ),(Ⅱ) 和 (Ⅲ) 在水溶液中的自组装性质.结果表明,在自组装过程中,3种卟啉分子均形成J型聚集体,从化合物(Ⅰ),(Ⅱ)到(Ⅲ),随着卟啉Meso位取代基供电子能力依次下降,分子间相互作用程度减弱,其纳米聚集体形貌由二维四方片状逐渐变成一维纳米带.这表明通过调节卟啉Meso位取代基的供/吸电子能力,可以调节分子间非共价键相互作用程度,从而控制卟啉分子自组装纳米结构的形貌.