Vibrational frequency photosynthetic reaction center

Characterization of the strongly coupled, low-frequency vibrational modes of the special pair of photosynthetic reaction centers via isotopic labelling of the cofactors, J. Am. Chem. Soc. 119 415. 

In analogy to Marcus theory, we also postulate that the nuclear degrees of freedom of the medium are too inert to change during the electron transfer step, i.e., the Born-Oppenheimer approximation can be applied for the nuclear degrees of freedom. Let us assume that the protein matrix coupled to electron transfer can be represented through N different oscillators where N is of the order of magnitude of the number of atoms in the protein, i.e., about 10 in the case of the photosynthetic reaction center. We denote the frequencies of these oscillators by a = 1,2,..., A and the associated vibrational coordinates by o = 1 2,..., AT. Let us assume further that each mode... 

Fig. 4. 23 The spectrum of a photochemical hole burned in the long-waveloigth absorption band of a sample of photosynthetic bacterial reaction centers at 5 K [68]. The gray curve is the difference between absorption spectra measured with the excitation laser on and off. The excitation frequency was 10,912 cm. Note the sharp zero-phonon hole PH, upward arrow) at 10,980 cm . The downward arrows indicate the centers of two discrete vibrational (phonon) bands that are linked to the zero-phonon transition. The solid curve is a theoretical hole spectrum calculated as described in the text...

---