Biosynthesis of chlorophyl studied by time-resolved Raman spectroscopy

本项目有两个目标：(1)通过对皮秒到微秒时间分辨吸收光谱的详细研究，在时间域内发现叶绿素生物合成过程中的新中间体，并从动力学研究中确定该过程的时间常数。(2)从中间体的时间分辨共振拉曼光谱可望确定其结构。针对第一个目标，改进仪器，重复实验，发现生物合成过程描述为：PChlide(S_1)-&gt；PS&gt；X-B-&gt；^^^&lt；&lt；plus-minus&gt；0.2&lt；micrn&gt；S&gt；X-690-&gt；^^&lt；Microrn&GT；S&GT；X-684Microrn&GT；S&GT；X-684MICRN&GT发现这些中间体与低温下的中间体是一致的。对于第二个目标，由于荧光很强，很难观察到新发现的中间体和其他中间体的时间分辨共振拉曼光谱。在现阶段，我们还没有成功地获得拉曼光谱。然而，用于时间分辨拉曼光谱的装置是在非相干光方法的基础上，通过使用宽带染料激光观测CARS或CSRS来确定飞秒振动位相弛豫。这项工作被扩展到电子退相时间测量，这些工作得到了许多科研人员的高度评价。首席调查员六次以上应邀在国际会议上发表演讲，并被邀请撰写三篇以上的应邀论文。

There were two targets of this project: (1)By detailed study of picosecond to microsecond time-resolved absorption spectroscopy, new intermediates in the biosynthetic processes of chlorophyl in the time region were to be discovered and from the dynamical study, the time constants of the processes were to be determined. (2)From the time-resolved resonance Raman spectra of the intermediates, the structure were expected to be determined.Concerning the first target, after improving the apparatus, and repeating the experiment the biosynthetic process was found to be described as:PChlide-650->PChlide(S_1)->^^^< PS>X-B ->^^^<<plus-minus>0.2<micrn>S>X-690 ->^^^<<plus-minus>20<micrn>S>X-684 ->^^^<<plus-minus>0.5<micrn>S> Chlide-678->^^^<5<plus-minus>2.0<micrn>S>Chla.All the intermesiates were found to be correspondent with those at low temperature.Concerning the second targer, it was very difficult to observe the timeresolved resonance Raman spectra of the newly found and other intermediates because of the very in tense fluorescence. At the present stage, we have not yet succeeded in getting the Raman spectra. However, the apparatus constructed for the time-resolved Raman spectra was used for the determination of femtosecond vibrational phase relaxation by observing CARS or CSRS using broad band dye laser on the basis of incoherent light method. The work was extendod to the electronic dephasing time measurement and these works were highly evaluated by many scientific research people. The head investigator was invited more than six times to give talks at the international conferences and was asked to write more than three invited papers.