Solvent effects on the electron-vibration coupling constant of β-carotene

Solvent effect plays an important role in determining electron-vibration coupling constant, however, the physical properties of solvent effects and the relationship between them still need to be investigated. We measure the UV-visible absorption and Raman spectra of β-carotene in 10 typical solvents. The results show that polarizability and dielectric constant of solvent have a significant effect on the electron-vibration coupling constant of β-carotene. With the increase of polarizability, no matter whether the solvent is of polarity, Huang-Ryes factor and the electron-vibration coupling constant of β-carotene decrease and the Raman scattering cross section of β-carotene increases. As to nonpolar solvent, Huang-Ryes factor and the electron-vibration coupling constant of β-carotene decrease with increasing the dielectric constant of the solvent. For polar solvent, no good regularity is obtained. In this paper, the regularity of solvent effect on the electron-vibration coupling constant is presented, which can provide a reference for how to choose the solvent in studying the electron-vibration coupling constant.