The anomaly of the ν₁‐resonance Raman band of bβ‐carotene in solution and in photosystem I and II

We have studied the resonance Raman spectra of β‐carotene in solution and in protein‐complexes using laser excitation at various wavelengths in the visible region. Main focus was laid on the ν 1 ‐band, which shows an anomalous behaviour upon variation of the excitation wavelength resulting in a frequency shift of the peak maximum. This shift is due to different excitation profiles of two closely spaced modes as shown previously for β‐carotene in solution. In this work, we have extended the studies to the antenna pigment in photosystems I and II (PS I and PS II).