A STUDY OF THE SPECTROSCOPIC AND THERMODYNAMIC PROPERTIES OF FURAN BYMEANS OF PHOTOABSORPTION, PHOTOELECTRON AND PHOTOION SPECTROSCOPY

Three experimental techniques (photoabsorption, photoelectron, and pho toion spectroscopy) have been used to study the spectroscopic and ther modynamic properties of furan. The absolute photoabsorption cross-sect ions of furan-h(4) and furan-d(4) have been measured using a double io n chamber and a new Rydberg series converging onto the G(2)A(1) ionisa tion threshold has been observed. HeI-excited photoelectron spectra of the X(2)A(2), the A(2)B(1) and the G(2)A(1) states of furan-d(4) have been recorded. Vibrational structure has been observed in all three b ands and has allowed the energies of the nu(3), nu(4), nu(6) and nu(8) vibrational modes to be determined. Time-of-flight mass spectra have been recorded using monochromatic synchrotron radiation, and appearanc e energies have been measured for 19 fragment ions and the doubly char ged parent ion. The fragmentation processes leading to the production of several high-intensity fragment ions have been modelled using ab in itio and semi-empirical methods. (C) 1998 Elsevier Science B.V. All ri ghts reserved.