Absorption and luminescence excitation spectra of ClF are recorded in the vacuum ultraviolet employing synchrotron radiation. A broad band (120-130 nm) due to transition to the ion-pair state E(0(+)) and sparse transitions to Rydberg states are observed. All Rydberg states are predissociated and their excitation yields no luminescence. Perturbations by the 4s sigma(1)Pi(1) and 4p pi(1)Sigma(+) Rydberg states result in characteristic dips in the E(0(+)) state luminescence excitation spectrum. Excitation above the Cl* + F dissociation threshold results in luminescence from ion-pair states of ClF or Cl-2 populated in reaction of Cl* with ClF or Cl-2. (C) 2010 Elsevier B.V. All rights reserved.