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Synthesis and spectroscopy studies of fullerenes and discovery of macroscopic quantities of doped fullerenes
[摘要] Synthesis techniques of carbon arc and laser vaporization in the furnace for production of fullerenes have been developed. The optimum conditions for the high yields of fullerenes were tested and studied. A fullerene growth model was proposed to explain the formation of the fullerenes and the extraordinary high yield of C$sb{60}$. The results of a test of this growth model was in agreement with the implications of the model. The electronic spectra of neutral C$sb{60}$ and C$sb{70}$ in the regions from 375 to 415 nm and 595 to 640 nm have been studied in a supersonically cooled molecular beam by resonant two-photon ionization spectroscopy method. Sharp spectral features were observed in both regions for C$sb{60}$ and in only the longer wavelength region for C$sb{70}$. Neither molecule has the spectra that correspond to the diffuse interstellar bands. The first method to produce macroscopic quantities of internal metal-doped fullerenes was developed successfully and improved. Lanthanum-doped fullerenes were produced by laser vaporization of a lanthanum oxide/graphite composite rod in a flow of argon at 1200$spcirc$C. Many properties of these endohedral complexes were investigated in detail. Similar results were obtained with yttrium-doped fullerenes, and double-doped endohedral fullerene complexes were first observed as a stable species in both sublimed film and toluene solution. Macroscopic quantities of other interesting metal-doped or B-doped fullerenes have been obtained and studied. Purification of these metal-doped fullerenes is in the process.
[发布日期]  [发布机构] Rice University
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