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Optical absorption spectra of nanoclusters of lead iodide, synthesized by the colloidal technique, have been investigated. It is shown that the absorption peaks are due to different orders of interband transitions of a nominally single size of particles rather than the first-order transitions of a number of discrete sizes of particles, as reported earlier. The model used to explain the spectra of lead iodide has also been used to account for the optical absorption peaks of colloidal mercuric iodide and bismuth tri-iodide. ͓S0163-1829͑98͒01443-X͔

The morphologies of the fullerene targets and the ablated fullerenes to determine the optimal conditions of excitation of the C60-containing targets have been analyzed. The optimization of fullerene-containing plasma conditions allowed the enhanced harmonic generation in these plasmas using laser radiation of different wavelengths, pulse durations, and phase modulation. A comparison between the harmonic generation in single-atom/ion-containing plasmas (using bulk carbon, silver, and indium targets) and fullerene-rich plasma plumes showed better conversion efficiency for the latter medium. The influence of phase modulation of the fundamental radiation in fullerene plasmas on the spectral properties of harmonics has been studied.

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The collision-induced decompositions of the [ M + Lil+ and ( M + Agl+ ions of per-0-acetyl-and per-0-benzyla-D-thioglycosides having phenyl sulphide, phenyl sulphoxide and phenyl sulphone as the aglycone moieties were studied. The [ M + Li] + ion of the acetyl derivative of the phenylthioglucoside shows loss of AcOLi, whereas its [ M + Agj+ ion shows elimination of PhSAg. Their sulphoxide and sulphone derivatives lose the C(l) and C(2) substituents to form the glucal under both Li+ and Ag + cationization conditions. The corresponding benzyl derivatives do not show the loss of metal. The formation of glucal leads to ring fragmentation by retro-DielsAlder reaction in the ring-activated benzyl derivatives.