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Fullerene hydrides and studies toward the syntheses of fulvalenes

Posted on:2006-01-21Degree:Ph.DType:Thesis
University:Rice UniversityCandidate:Peera, Asghar AFull Text:PDF
GTID:2451390005993500Subject:Chemistry
Abstract/Summary:
Benkeser reduction was used to synthesize highly hydrogenated fullerenes, C60H36, C60H38, C 60H40, C60H42 and C60H 44. 1H- and 13C-NMR spectra of HPLC purified fractions show that more highly hydrogenated fullerenes exhibit signals that are shifted upfield. The opposite trend was observed in 3He NMR spectra of the corresponding endohedral helium compounds. The trend in the 3He NMR is attributed to the change in the shape of various hydrogenated fullerenes.; Hydrogenated single-walled carbon nanotubes (H-SWNTs) were prepared via the dissolved metal reduction method in liquid ammonia and by Anhydrous Hydrazine in methanol. Spectroscopic analysis of the H-SWNTs shows that hydrogen is covalently attached to the tubes. Scanning Tunneling Microscopy (STM) images of the hydrogenated tubes show bright regions around the circumference of the tube that most likely correspond to the region covered by hydrogen.; Precursors of two fulvalenes (calicene and triafulvalene) were prepared by multi-step synthetic procedures. The calicene precursor was obtained by base-induced dehydrobromination, while that of triafulvalene was obtained by a metathesis reaction using first generation Grubbs catalyst. The two precursors are attractive candidates for the parent compounds by using solid fluoride as the dehalosilylation inducing reagent in the final step.
Keywords/Search Tags:Hydrogenated fullerenes
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