We report the integral cross sections per scatterer (i.e. elastic collision, phonon excitations, vibrational excitations, electronic excitations and ionization) for 1-100 eV electron scattering in an amorphous film of ice condensed at a temperature of 14 K. The integral cross sections are determined relative to the total from a two-stream multiple-scattering analysis of the electron energy distribution backscattered from the film. Their energy dependence is obtained from both the analysis of the elastic electron reflectivity as a function of the film thickness and the vibrational electron energy-loss spectra measured for several incident energies and large film thickness. The magnitude and various features found in the energy dependence of the cross sections are discussed, whenever possible, by comparison with data and with scattering mechanisms available in the gas phase. Microcospic effects, which are implicitly included in cross sections determined in this way, are discussed in terms of interference and coherent multiple-scattering contributions among the scattering sites as well as interactions of the scattering sites with their neighbors in the condensed phase.

Oscillator strengths for the inner-shell excitation (C Is, O Is, Fe 2p, and Fe 3p) of eight gas-phase organoiron complexes Fe(CO)5, Fe2(CO)9, RFe(CO)3 (R = C4He, c-C6H8, c-C8He), and CpFeCpR' (R' = H, C2H3, C4H9) have been derived from electron energy loss spectra recorded under electric dipole scattering conditions. Tentative spectral assignments have been made based upon comparison to the spectra of free ligands and to previous gas-phase studies of related organometallic species. The spectra provide insight into how core excitation spectroscopy reflects the iron-ligand bonding in these complexes. The C Is, 0 Is, and Fe np spectra of related molecules in a series (e.g., carbonyl complexes or ferrocene derivatives) have a similar shape, suggesting similar origins of the spectral features. Small variations through each series have been interpreted in terms of changes in the electronic structure associated with changing substituents. The sensitivity of core spectra to ligand-ligand electronic interaction has been assessed through comparisons to spectral simulations based on the sums of experimental spectra of free ligands and single-ligand complexes. Spectral simulations based on extended Hückel (EHMO) calculations have also been carried out for C Is and Fe 2p excitation in Fe(CO)6 and Fe2(CO)9. The Fe 2p spectra are surprisingly sensitive to the type of ligands present in the complexes.

Oscillator strength spectra in the region of B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-1,2-orthocarborane, closo-1,7-metacarborane, closo-1,12-paracarborane (C2B10H12)] have been derived from inner-shell electron energy loss spectra (ISEELS) recorded under electric dipole-scattering conditions. Total ion yield spectra recorded at high resolution with synchrotron radiation are also reported. The spectral features are assigned on the basis of comparisons with spectral predictions derived from the results of ab initio and semiempirical (extended Hückel) molecular orbital calculations. The isomeric and core level variations in the discrete core excitations are related to changes in orbital symmetries as well as variations in electron localization in these isomers. The ionization efficiency in the region of the B 1s and C 1s edges is derived.

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