A search for subpicosecond absorption components in photosystem II reaction centers

✍ Scribed by S.W. McCauley; A.P. Baronavski; Jane K. Rice; M.L. Ghirardi; A.K. Mattoo

• Book ID: 103033300
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 563 KB
• Volume: 198
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)80024-6

✦ Synopsis

The transient absorption kinetics of spinach photosystem II reaction centers were measured at 672 nm (detection bandwidth z 11 nm) following excitation at 3 10 nm. A temporal resolution of z 50 fs was used which is three times higher resolution than the current literature value. We observed a very fast absorption decrease with a rise time of I SO + 15 fs followed by a 13 f 4 ps recovery. The kinetics of the recovery step did not reveal a 3 ps component, however, a slight break in the data suggests a more complicated fit may explain the data as well or better. Based on a comparison of the rise time reported here and those reported by Durrant et al., the relaxation from S,, to S, occurs very rapidly, within the 150 fs initial absorption decrease.