single electron transfer (rus. одноэлектронный перенос) — an intermediate stage of many organic and biochemical reactions characterised by transfer of one electron from donor to acceptor.

Description

This process is very common in nature. In fact, it is a redox process. The transfer usually results in a state with split charges: DA → D+A (D — donor, A — acceptor of electron).

Electron transfer plays a key role in many biochemical reactions. For example, one of the critical stages of photosynthesis is the transfer of an electron through a bilayer cellular membrane. The process begins at a dimer of bacteriochlorophyll (P) and includes a series of electron transfers from one substance to another (see fig.). The final electron acceptor is a quinine molecule (QB).

Illustrations

Energy diagram demonstrating transmission of an electron in reaction centers of purple bac
Energy diagram demonstrating transmission of an electron in reaction centers of purple bacteria. P — a dimer of bacteriochlorophyll that, when exposed to light, changes state into excited state P*, which makes it an electron donor. BChl — bacteriochlorophyll, BPh — bacteriophaeophytin, QA — alternate quinone, QB — electron accepting quinone. Electron transfer time is indicated for each stage.

Author

  • Eremin Vadim V.

Sources

  1. Eremin V. V Quantum dynamics of redox reactions (in Russian). // Priroda. 2006. №5. 15–22 pp.
  2. Chupakhin O.N. Single-electron transfer in organic chemistry (in Russian). // Sorosovskijj obrazovatel'nyjj zhurnal. 2001. V. 7, №10. 33–37 pp.
  3. Hoff A. J., Deisenhofer J. Photophysics of photosynthesis. Structure and spectroscopy of reaction centers of purple bacteria // Physics reports. 1997. V. 287. 1–247 pp.

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