Raman excitation profiles of β -carotene - novel insights into the nature of the ν1-band

In the present work we have studied β-carotene dissolved in dichloromethane by means of resonance Raman spectroscopy. To obtain the Raman excitation profiles Raman spectra of /3-carotene have been acquired at various wavelengths throughout the visible region. It was found that the position of the prominent peak at ca. 1524 cm -1 varies with the excitation wavelength indicating the involvement of two different modes. Possible origins of the different enhancement pattern of the two modes are discussed.