【作者】 齐平；

【导师】 张汉壮； 李子亨；

【作者基本信息】 吉林大学 ， 光学， 2013， 硕士

【摘要】 卟啉是一种重要的维持动植物生命体征的物质，被广泛应用于多种生物活性的重要研究上，因卟啉自身的π键和共轭环状结构，卟啉分子的光谱特性也非常受其关注。LB（Langmuir-Blodgett）膜技术因其使分子排列有序、规则、厚度可控等优点被利用在生物膜、化学修饰电极等多个方面，因此，我们结合卟啉本身具有的良好的光电性能制备了卟啉LB膜，研究了卟啉LB膜的光谱和电化学特性，以期探索卟啉分子在ITO电极表面的排列结构、电荷储存特性和转移特性，揭示其结构与功能之间的关系，这对于从分子水平阐述化学修饰电极的电荷转移机理有重要意义。本文首先介绍了LB膜的制备方法，卟啉及四能级轨道模型理论。然后对卟啉的紫外可见吸收谱和主要红外吸收峰进行了指认，对其进行荧光光谱测试并阐述了荧光机制。第四章以ITO为基底组装了卟啉LB膜，对其进行了光谱(紫外-可见吸收光谱、红外光谱)和电化学(循环伏安法和恒电位阶跃法)特性研究；电化学方法研究了卟啉LB膜的电荷转移和存储特性。结果表明， LB膜有序性和拉膜次数都影响电荷转移，2次膜随着有序性的增加，电导率增大，4次膜随着有序性的增加，电导率降低；相同表面压下，随着膜层数的增多，电导率降低。紫外-可见吸收谱表明，当表面压约为10mN/m时形成有序膜，没有表面压时形成无序膜，约为5mN/m时有序无序都存在。红外光谱进一步证实了有序膜的形成。膜为2次时，储存电量随着有序性的增加显著增加，膜为4次时，储存电量随着有序性增大不明显；IR谱证明了卟啉LB有序膜能够靠卟啉环形成头对头相互作用，也能靠羟基形成脚对脚的相互作用，这种作用会影响卟啉膜的电荷转移特性。理论计算表明，卟啉环上碳间的键长介于单键和双键之间，卟啉环整体表现为共轭特性，以大π键形式存在。大π键有序排列后能够有效释放和存储电子，具有很高的电化学活性。更多还原

【Abstract】 Porphyrin is a kind of material for maintaining plant and animal life. It can bewidely used in a variety of biological activities. Because of its large conjugatedporphyrin ring structure and pi-conjugated, people also pay large attention to itsspectral properties. LB（Langmuir-Blodgett）technology has a lot of advantages, suchas the molecular order, controllable thickness and so on. So it can be used inbiological membrane and chemically modified aspects. Combining the photoelectricproperties of good prophyrin itself with LB technology, we prepared the porphyrin LBfilms to study the electrochemical and spectral properties. We hope to discuss theporphyrin molecules order and charge transfer on the ITO electrode. Moreover, wereveals the relationship between its structure and function. It has importantsignificance for the charge transfer mechanism on chemically modified electrode fromthe molecular level.In this paper we fistly introduces the method of preparing LB film, porphyrins andfour level energy model theory. Then the porphyrin UV-visible absorption spectra andmainly infrared absorption peaks were identified. We also tested the fluorescencespectra and expounds the fluorescence mechanism. In the fourth chapter the porphyrinLB films prepared on the ITO substrate were assembled by the spectra method(UV-Vis absorption spectroscopy, infrared spectroscopy) and electrochemical(including cyclic voltammetry and constant potential jump method) to study thecharge transfer and storage properties characteristics of porphyrin LB films. Theresults show that the ordering and the layer-number of LB films all affect chargetransfer: As the ordering increases, the conductivity increases; electrical conductivitydecreases with the increase of layer number. UV-Vis spectrum show that orderedfilms form with the surface pressure of about10mN/m and disordered membranesform without surface pressure. The ordered and disordered mix when the surfacepressure is about5mN/m. The formation of ordered membrane has been furtherconfirmed by infrared spectra. With the ordering increasing, the charge amount storedin films which are stretched2times significantly increases. However, in the filmsstretched for4times, the stored charge amount’s changing with the orderingincreasing is not obvious. IR spectra prove that, not only relying on the porphyrin ring, the ordered porphyrin LB films can form head to head interactions, but also form theinteractions of end to end by hydroxyl, which principle affects the charge transfercharacteristics of the porphyrin films.The theoretical calculations show that, the carbon bonds length on porphyrin ringare all between the single and double bonds. Because of π bonding, porphyrin ring forthe overall is performance of conjugation characteristics. When the π bond is preparedorderly, it can effectively release and storage of electronic and has very highelectrochemical activity.更多还原