Photochemistry of Organic Compounds

涉及电子转移的化学过程中的能量和介质要求将用专门设计的设备进行探测。要研究的供体-受体对系统将允许研究异构体发射和电荷转移发射之间的关系，光诱导电子转移的能量学和速率之间的关系，以及蛋白质作为生物光诱导电子转移介质的作用。所研究的双色团体系之一将具有一个取代的蒽和一个由不同长度的间隔段隔开的二甲基苯胺基团作为供体/受体对。该间隔剂将由亚甲基或酰胺单元组成。这样一系列的化合物将允许通过取代基的变化来探测这些过程的能量学，并通过改变间隔的长度来探测转移过程的几何形状。研究将使用瞬态光谱仪和超音速射流进行，以获得高分辨率光谱。这项来自有机动力学项目的资助用于支持芝加哥大学杨北昌教授的研究。控制分子内两个基团之间电子转移的因素将被研究。其中一个基团会因吸收光能而被提升到激发态。随后，利用快速光谱技术可以研究电子从该激发态基团到分子中另一个电子受体基团的转移。该过程的能量学将通过用其他取代基改变其中一个基团来探测，这些取代基可以促进或阻碍电子转移。电子转移在包括光合作用在内的许多生物过程中将光能转化为化学能的过程中起着至关重要的作用，因此这项研究将引起广大科学家的极大兴趣。

The energetic and medium requirements in chemical processes involving electron transfer will be probed with specially designed equipment. The systems of donor-acceptor pairs to be investigated will allow studies to be made of the relationship between exciplex emission and charge transfer emission, the relationship between energetics and rates of photoinduced electron transfer, and the role of proteins as the media in biological photoinduced electron transfer. One of the bichromophoric systems to be studied will have as the donor/acceptor pair a substituted anthracene and a dimethylaniline group which is separated by a spacer of varying length. The spacer will consist of methylene or amido units. Such a series of compounds will allow the energetics of these processes to be probed by changes in substituents and the geometry of the transfer processes to be probed by varying the length of the spacer. The studies will be carried out with a transient spectrometer and a supersonic jet to obtain high-resolution spectra. %%% This grant from the Organic Dynamics Program supports the research of Professor N. C. Yang at the University of Chicago. Factors that govern electron transfer between two groups within a molecule will be studied. One of the groups will be promoted to an excited state by the absorption of light energy. Subsequently, electron transfer from this excited group to the other electron acceptor group in the molecule can be studied by fast spectroscopic techinques. The energetics of the process will be probed by altering one of the groups with other substituents which facilitate or retard electron transfer. Electron transfer is of fundamental importance in the conversion of light into chemical energy in many biological processes including photosynthesis and thus this research will be of considerable interest to a wide range of scientists.