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Structural Elucidation of Fullerenes and Traditional Inorganic Compounds

Posted on:2016-07-06Degree:Ph.DType:Dissertation
University:University of California, DavisCandidate:Ghiassi, Kamran BlakeFull Text:PDF
GTID:1471390017482139Subject:Chemistry
Abstract/Summary:
With the exception of the introductory Chapter 1, this dissertation focuses on five primary research projects that were published as peer-reviewed articles in academic journals. It does not reflect the other published works and collaborations that were also conducted during candidacy. However, a full publication list is provided in Appendix A.;Although each chapter was originally inspired by the pursuit of fullerene chemistry, Chapter 2 does not include any fullerenes. Rather, it contains structural elucidation of ruthenium chemistry with carbon disulfide. This project was serendipitously discovered whilst investigating the potential reactivity of RuCl2(PPh3)3 with C60 . It became obvious that the two components did not react or interact, and a curious ruthenium product, RuCl2(S2CPPh3 )(PPh3)3, formed. Although there is existing literature on the subject matter, this product was never fully and correctly identified. This chapter provides a synthetic route and clarification to several ruthenium compounds analyzed via 31P{1H} NMR, FT-IR, and UV-vis-NIR spectroscopies as well as cyclic voltammetry and single-crystal X-ray diffraction.;Chapter 3 details interactions with between the organic molecule hexakis(( E)-3,3-dimethyl-1-butenyl)benzene (HB) with C60 or C 70 analyzed via single-crystal X-ray diffraction. The six arms of this substituted benzene molecule interact with either fullerene to form clamshell assemblies in a chain-like fashion. This molecule was chosen due to its similarity to the classic and popular nickel(II) octaethylporphyrin, Ni(OEP). It proved interesting to study a similar, purely organic host-guest system, since the interactions of HB or Ni(OEP) with fullerenes are very similar. Of interest, the C60 and C70 cocrystal structures with HB show the same 2:1 ratio of HB:fullerene, the significant difference being the dihedral angle between the two HB molecules.;In a similar fashion, Chapter 4 provides a wealth of fullerene cocrystal structures of host-guest nature. The fullerenes C60 and C 70 were cocrystallized with brominated benzene molecules, hexabromobenzene and 1,2,4,5-tetrabromobenzene (1,2,4,5-TBB). Other brominated benzenes were attempted during the cocrystallization, however were unsuccessful. Using either hexabromobenzene or 1,2,4,5-TBB, the cocrystal structures with C70 all showed waves of bromine---bromine interactions. These halogen---halogen bonds are completely absent in the C60 cocrystals.;Chapter 5 analyzes the previously-determined structure of C60•2S 8. It was found that this crystal structure was incorrectly assigned at room temperature, and its low temperature structure was not obtained. During the collection of data at 90 K, a phase change was discovered and modelled, thus giving a second polymorph. Another crystal habit was analyzed, giving a third polymorph at room temperature and a fourth at 90 K. This phase change was also modelled. The four polymorphs were examined crystallographically in order to better understand the intermolecular interactions of these systems.;The simple small molecules of similar size, diiodine and carbon disulfide, were cocrystallized with the fullerenes C60 or C70. Diiodine and/or carbon disulfide serve as useful cocrystallization agents, yielding well-ordered fullerenes in the crystal structures. Chapter 6 investigates the supramolecular structure of these cocrystals. Although diiodine and carbon disulfide are of similar size, the cocrystals do not have analogous compositions. In all of the mixed cocrystal systems, the diiodine and carbon disulfide molecules share common sites and common orientations.
Keywords/Search Tags:Carbon disulfide, Fullerenes, Chapter, C60, Cocrystal, Molecules
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