The excitation of pure liquid cyclohexane, 2,2,4 trimethylpentane and tetramethylsilane in the vacuum ultraviolet is examined with the help of a new experimental technique allowing fine measurements of single-photon absorption spectra of pure liquids with the synchrotron radiation, up to 10.8 eV. The first experimental results are presented, discussed and compared to the gas phase and photoconduction data already published on these media. A description of the molecular relaxations below the conduction bands of these liquids is proposed. (C) 2003 Elsevier B.V. All rights reserved.