【作者】 孙瑞平；

【导师】 卢小泉；

【作者基本信息】 西北师范大学 ， 分析化学， 2011， 硕士

【摘要】 光合作用是地球上绝大多数生物的物质和能量来源,是生物-地化循环中至关重要的环节,是地球上普遍存在而又独特的植物生理过程,也是制约生态系统中生物的生产量的最重要的生理过程,光合作用的研究在理论和生产实践上都具有重大的意义。因此,研究光合作用过程的能量转化、电子转移、能量传输对于认识、理解、掌握许多重要自然发展规律及人工科技具有重要的意义。光合作用光能的高效吸能、传递和转换,及其控制的微观机理是当前国际光合作用基础研究中的核心问题。电子转移(Electron Transfer, ET)是生命活动的基本过程,生物体的大部分生命活动如血红蛋白的载氧过程,叶绿体中的光和作用,线粒体中的呼吸作用等都和电子转移过程密切相关,并且多数生命过程都是在生物膜上发生的。而界面包括液/液界面及固/液界面被认为是比较简单的模拟生物膜模型。基于此,本文主要以卟啉化合物、叶绿素与苯醌作为配对物质,较为系统地研究了其在模拟生物膜界面(液/液和固/液)上的电子转移过程和光电转换行为。这对于光合作用过程的研究具有十分重要的意义。随着科学技术的飞速发展及各学科间的相互渗透,界面化学的研究也会遇到越来越多的挑战和机遇,而更多精密技术和更合理方法的应用,必将为人类认识自然开拓更广阔的前景。本文结合扫描电化学显微镜(Scanning Electrochemical Microscope, SECM)技术、薄层循环伏安法及SECM-紫外可见光源联用研究了光合作用过程中光电转换过程及金属卟啉在仿生界面上的电子转移过程。本文共分为四部分,主要包括以下内容:1.概述了光合作用发展历程及其研究意义,简单述说了常用的光合作用过程研究方法。回顾了液/液界面电化学的发展背景,基本构型及应用前景。详述了两种主要研究方法:SECM和薄层循环伏安法(TLCV)的工作原理、定量分析理论及应用,并概述了光电化学的的概况。2.用铁卟啉与苯醌作为氧化还原对对光合作用原初反应进行了简单的探讨,利用不同取代基在反应中的驱动力不同来模拟调节光照强度,并对液/液界面驱动力与界面电子转移反应间的关系进行了探讨,发现在驱动力比较小的时候反应速率随着驱动力的增大而增大,但是当驱动力继续增大时,反应速率反而随着驱动力的增大而减小了,这一结果间接揭示可能在植物光合作用过程中,并非光照强度越强光电转换效率就越高,在这期间可能存在一个最适光照,当光照强度到达这点时,光电转换效率达到最大。另外,利用SECM也研究了硝基苯中铁卟啉与水相中苯醌间的电子转移过程,并对反应物质浓度及共同离子对速率常数的影响做了探讨。3.鉴于薄层循环伏安法在液/液界面上的优势,使用这一方法对光合作用原初反应过程进行了简单的模拟应用TLCV方法研究了苯醌(BQ,水相)-铁卟啉(FeTPP,有机相)体系在硝基苯(NB)/水(W)界面上的电子转移过程。并与SECM进行了对比研究,两种方法获得的实验结果相吻合,这不但证实了TLCV方法研究液/液界面异相电子转移反应的可靠性,并且还拓展了TLCV的研究范围。4.应用SECM与紫外-可见光源联用来研究从菠菜中提取出来的叶绿素的光电转换过程,利用I-t技术对反应过程的各种条件进行了优化,并对叶绿素-苯醌体系电子转移情况及水相浓度不同时对反应速率的影响情况进行了研究。更多还原

【Abstract】 Photosynthesis is the most biological material and energy sources in the earth, the vital link between biological and earth, the widespread and unique plant physiology process, and the most important biological production restricted ecological system in physiological processes. Researching photosynthesis has great significance on production practice and theory. Therefore, study the energy conversion, electron transfer, energy transmission of photosynthesis process has the vital significance for understanding and mastering many important natural development regularity and artificially technology. Photosynthesis light energy efficiently absorpt, transfer and convert the energy and the microscopic mechanism its controled is the core issue of basic research in the current international photosynthesis. The electronic transfer is the basic process in life activity, most of the life activities such as organism of hemoglobin, the process of carrying oxygen chloroplast in the mitochondria, photosynthesis and respiration, are all closely related with the electronic transfer process, and most life process was happening on biological membrane. The interface including liquid/liquid interface and solid/liquid interface are thought to be more simple modeling in biological membrane model. Based on this, the paper mainly used porphyrin compounds, chlorophyll and benzene quinone as the matching material, and systematically study the electron transfer process and photoelectric behavior on the modeling of biological membrane interface (liquid/liquid and solid/liquid). This has certain significance for photosynthesis process studies.Along with the rapid development of science and technology and interdisciplinary mutual infiltration, interface chemical study will also meet more and more challenges and opportunities, and more precision technologys and reasonable methods for the application of recoganizing nature, will have a broad prospect.Combining with Scanning Microscope Scanning Microscope (Electrochemical Electrochemical, SECM) technology, thin layer cyclic voltammetry and SECM - uv-vis illuminant coupled research the photoelectric conversion process in photosynthesis process and the electronic transfer process of metallic porphyrin in bionic interface. This paper is divided to four parts, mainly include the following content:1. Summarizes the development and research significance of photosynthesis, simple told the photosynthesis process research methods which commonly used. Review the development background, basic configuration and application prospect of liquid/liquid interface electrochemical. Told the details of two main kinds research methods: SECM and thin-layer cyclic voltammetry (TLCV) work principle, quantitative analysis theory and application, and summarizes the situation of photoelectric chemistry.2. Discussing the primal reactions of photosynthesis used iron porphyrins and benzene quinone as redox in the paper, using different driving force come from different substituents simulate the different light intensity, and discussed relations between driving force and electronic transfer reaction. We found that the reaction rate is increases with increasing of driving force when the driving force is smaller ,but decreases with increasing of driving force when driving forces is larger. This results indirect may process of plant photosynthesis, not the light intensity more light the electric conversion efficiency is higher, during which there may be an optimal illumination, when light intensity reach this dot, photoelectric conversion efficiency achieve to maximum. In addition, use SECM also studied the electronic transfer process between iron porphyrins in nitrobenzene and benzoquinone in water, and the influence the concentration of reaction matter and common ion to the rate constant are discussed.3. For the advantage of TLCV method in liquid/liquid interface, we used it to simulationed the photosynthesis original reaction process simply with benzene in aqueous phase and iron porphyrins in organic phase and study the electron transfer process. Then comparaed it with SECM and found that the experimental results come from this two methods are coincide. Which not only confirmed the reliability of TLCV but also expand the study scope of TLCV. 4. Application SECM and ultraviolet-visible illuminant coupled to study the chlorophyll’photoelectric conversion process which extracted from spinach, using I - t technology optimized the conditions of reaction process, studied the electronic transfer between chlorophyll and benzene system, and the influence of vapor concentration in water to the reaction rates.更多还原