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This thesis is based on two main parts. The first part concerns purification and functionalization of carbon nanotubes (papers I-III), and the second part is related to the synthesis of organometallic fullerene derivatives (papers IV-VII): Two oxidative methods involving aqueous nitric acid were compared with respect to their capability to introduce carboxylic groups into single walled carbon nanotubes, and several literature methods for esterification and amidation of these groups have been evaluated with focus on efficiency and reproducibility in forming covalently functionalized products soluble in organic media. Amidation proceeding via a SWNT-(COCl)n intermediate yielded the expected covalent product, whereas carboxylate salt formation dominated with other attempted methods. Esterification was achieved via the acyl chloride method and via alkylation of SWNT-(COO–)n, the latter being the more efficient method. A new, reagent-free method for purification of single- and multi walled carbon nanotubes has been developed. Microwave treatment dissociates non-nanotube carbon and disperses it into an organic solvent, resulting in very pure carbon nanotubes within a few minutes of heating, without the involvement of acidic/oxidative reagents. According to thermogravimetric analysis, Raman and IR spectroscopy, as well as SEM, the process yields nanotubes with a low degree of defects. A non-covalent approach has been employed to prepare nanotubes functionalized with glycosides. Derivatives of galactose and lactose were covalently linked to a pyrene moiety and the thus formed pyrene-glycosides were non-covalently attached to single- and multi walled carbon nanotubes by π-π interactions. Fluorescence titrations have been used to quantify the formed supramolecular assemblies, which for SWNTs exhibits increased water solubility. A fulleropyrrolidine-(tricarbonyl)chromium complex was synthesized and fully characterized. IR spectroelectrochemistry was used to probe the redox state of the fullerene and provided evidence for electronic communication between the two electroacive moieties. A C60-ferrocene-C60 triad system was synthesized and characterized. Cyclic voltammetry and fluorescence studies suggested electronic communication between ferrocene and the two fullerenes. Finally, the synthesis and initial characterization of short fullerene-ferrocene oligomers are presented.

N-heterocyclic carbenes (NHCs) can be used as ligands for organometallics complexes, which can then facilitate numerous catalytic applications, such as, C-H activation, small molecule activation and numerous materials applications. The use of anionically-tethered NHCs for usage with electropositive metals has been pioneered by the Arnold group within the last decade. This thesis describes the synthesis of both aryloxide- and amide-tethered NHC organometallic complexes of s-, p-, d- and f-block metals to provide a platform for small molecule activation. Once synthesised, the reactivity of some of these complexes were tested by reaction with CO2 with the aim of turning a molecule considered a harmful (environmentally), waste product into value added products, potentially providing an alternative fuel source. Chapter One introduces the use of anionically-tethered NHCs for use in a number of organometallic complexes as well as their current potential as catalysts for a number of important small molecules. This chapter focuses upon the differences between complexes tethered with anionic O, N, P, S elements, f-element NHC complexes and the use of d-block NHC complexes for catalysis. Chapter Two contains the synthesis and characterisation of a number of aryloxy-tethered NHC p-, d- and f-block organometallic complexes using the ligand H2(LArO R)2. The synthesis of SnII complexes including the synthesis of new ‘normal’ ‘abnormal’ complexes given enough steric bulk around the Sn centre due to the lone pair present in Sn complexes, preventing one of the ligands binding through the classical carbene position and therefore binding through the backbone C4 carbon. The synthesis of MII (Zn, Co and Fe) complexes to compare the solid-state structure and binding mode of the carbenes. The synthesis and characterisation of MIII (Ce and Eu) complexes to assess the solid-state structure and binding modes within f-bock complexes. Chapter Three investigates the reactivity of the MII complexes (Sn, Zn, and Fe) with CO2. Successful reactions were characterised using NMR and further treated with alkynes to target catalytic reactions. Chapter Four contains reactions to target a number of amide-tethered bis (NHC) s-, p-, d- and f-block organometallic complexes using the proligand, H4(LN Mes)Cl3. Deprotonation studies undertaken with a number of bases to give the MI (Li and K) salts and MII (Mg) salts and proved to be unsuccessful upon isolation. Reactions to synthesise the p-, d- and f-block complexes were then undertaken using in situ free carbene production as well as the attempted isolation of the free carbene, both of which also proved unsuccessful. Chapter Five provides an overall conclusion to the work presented in Chapters Two, Three and Four within this thesis. Chapter Six gives the experimental and characterising data for the complexes and reactions.

The synthesis of two types of metallocenophanes is described: strained, ring-tilted [1]metallocenophanes with Al and Ga in bridging positions and Fe and Ru as transition elements and unstrained [1.1]ferrocenophanes with Al, Ga and In in bridging positions. [1]Metallocenophanes are potential monomers for the synthesis of organometallic polymers via ring-opening polymerization (ROP). After the successful synthesis of various starting monomers using the concept of intramolecular coordinating ligands, four different pathways of ROP were investigated. However, only one of these pathways proved successful in obtaining polymeric material. The starting monomers showed a surprising stability against commonly used initiators. This was attributed to an overly steric protection by the intramolecular coordinating ligands, thereby blocking the initiators, and a reduced ring strain, a consequence of the size of the bridging element.<p>[1.1]Ferrocenophanes belong to a class of dinuclear complexes where the two redox-active iron atoms are in close proximity with restricted flexibility. [1.1]Ferrocenophanes with Al, Ga and In in bridging positions were investigated. The redox properties of previously published [1.1]ferrocenophanes showed a fully reversible, stepwise, one-electron oxidation (FeII/FeII → FeII/FeIII → FeIII/FeIII). After the initial oxidation of the first iron center, a stable, mixed-valent monocationic species is created. The removal of a second electron from the second iron center therefore is more difficult, and occurs at higher potential to create the dicationic species. The difference in potential for the stepwise oxidation is directly related to the delocalization of the charge in the mixed-valent species. This delocalization mainly depends on the electronic properties of the bridging element. Depending on the bridging group 13 element, very different electrochemical properties were observed. For the alumina[1.1]ferrocenophane, no delocalization was detected, and a one-step, two-electron oxidation at the same potential was observed. For the inda[1.1]ferrocenophane, a more complex electrochemistry was observed that we attributed to an isomerization of the compound in solution. Only the investigated galla[1.1]ferrocenophane showed the expected stepwise oxidation-reduction behavior.

The synthesis of two types of metallocenophanes is described: strained, ring-tilted [1]metallocenophanes with Al and Ga in bridging positions and Fe and Ru as transition elements and unstrained [1.1]ferrocenophanes with Al, Ga and In in bridging positions. [1]Metallocenophanes are potential monomers for the synthesis of organometallic polymers via ring-opening polymerization (ROP). After the successful synthesis of various starting monomers using the concept of intramolecular coordinating ligands, four different pathways of ROP were investigated. However, only one of these pathways proved successful in obtaining polymeric material. The starting monomers showed a surprising stability against commonly used initiators. This was attributed to an overly steric protection by the intramolecular coordinating ligands, thereby blocking the initiators, and a reduced ring strain, a consequence of the size of the bridging element.<p>[1.1]Ferrocenophanes belong to a class of dinuclear complexes where the two redox-active iron atoms are in close proximity with restricted flexibility. [1.1]Ferrocenophanes with Al, Ga and In in bridging positions were investigated. The redox properties of previously published [1.1]ferrocenophanes showed a fully reversible, stepwise, one-electron oxidation (FeII/FeII → FeII/FeIII → FeIII/FeIII). After the initial oxidation of the first iron center, a stable, mixed-valent monocationic species is created. The removal of a second electron from the second iron center therefore is more difficult, and occurs at higher potential to create the dicationic species. The difference in potential for the stepwise oxidation is directly related to the delocalization of the charge in the mixed-valent species. This delocalization mainly depends on the electronic properties of the bridging element. Depending on the bridging group 13 element, very different electrochemical properties were observed. For the alumina[1.1]ferrocenophane, no delocalization was detected, and a one-step, two-electron oxidation at the same potential was observed. For the inda[1.1]ferrocenophane, a more complex electrochemistry was observed that we attributed to an isomerization of the compound in solution. Only the investigated galla[1.1]ferrocenophane showed the expected stepwise oxidation-reduction behavior.