【摘要】 利用飞秒泵探测技术研究了紫细菌光合反应中心RS6 0 1中的超快能量传递过程。通过选择激发反应中心中的不同色素 ,观察到了以不同色素为起点发生在飞秒时域的超快能量传递过程。从细菌去镁叶绿素H到辅助细菌叶绿素B的能量传递发生在约 130fs时间尺度 ,而通过激发色素B则观察到了从B到原始电子供体P的约2 40fs的超快能量传递。另外 ,P激发态的超快弛豫过程则说明其上、下激子能级间存在超快的内转换过程。通过对不同色素激发态的能量弛豫过程的分析 ,说明由原初电子供体P到原初电子受体H的电子传递过程在几个皮秒时间内完成 ,其中辅助细菌叶绿素B为该电子传递过程的中间态更多还原

【Abstract】 The ultrafast energy transfer process, which takes place in femtosecond time range, in bacterial photosynthetic reaction center RS601 was investigated using femtosecond pump probe technique with selective excitation. Upon 755 nm excitation, the excited state of bacteriopheophytin H decayed to bacteriochlorophyll B with a time constant of about 130 fs, while the excited state of B transported the energy to its energy acceptor, the dimeric bacteriochlorophyll P, in about 240 fs with the 800 nm excitation. The internal conversion process between the upper and lower exciton levels of special pair P might exist upon the excitation of 850 nm pulses. In addition, from the results obtained in our experiments, the charge separation and electron transfer from P to the acceptor H was also observed via the real intermediate B within a few picoseconds.更多还原