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The concept of this thesis is to effect greater control over the crystalline state of radical cation salts in order to enhance electron transport, and to allow for the incorporation of additional functionality such as optical activity or magnetism. The salts formed are based on the bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) framework, and are produced using the technique of electrocrystallisation. In attempts to control the crystal packing arrangements observed, a number of approaches have been explored including the incorporation of chirality, hydrogen bonding interactions and coordinate bonding interactions. These properties have been installed on the electron donor molecule and/ or the charge stabilising anion component. This thesis presents a novel radical cation salt that has been prepared from ET and the sulfamate anion, and which exhibits ordered channels of hydrogen bonded anions and water molecules extending in one crystallographic dimension. This research has also discovered an unusual chiral crystallographic packing observed in a novel semiconducting radical cation salt formed from ET and the bromide anion. Also presented are the synthesis of a family of metal-binding electron donors and the first radical cation salts formed from these, including a perrhenate salt which is both N-protonated and oxidised, giving an overall charge of +2 on the electron donor molecule. A group of novel aldehyde-functionalised donors are discussed, one of which could lead to a Little-type superconductor, and the syntheses towards a bis(donor) molecule containing a spiro centre, and separately a porphyrin appended electron donor are presented.

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Chapter 1 presents the most relevant literature in the fields of borane, carborane and metallacarborane chemistry, providing the reader with an overview of these topics. In the later part the focus changes to 1,1′-bis(o-carborane). Chapter 2 describes the attempted two electron reduction/metallation and single cage decapitation/metallation chemistry of 1,1′-bis(o-carborane). Also described are the analysis of two dimensional 11B-11B correlation spectra of all the products and the cal-culation of weighted average 11B chemical shifts of the individual cage components of these products which are discussed with respect to the parent compound. Chapter 3 describes the double cage decapitation of 1,1′-bis(o-carborane) with excess KOH and metallation with {(arene)Ru} and {CpCo} fragments at room temperature. Metallation with {(arene)Ru} resulted in two products whereas metallation with {CpCo} yielded the same two structure types plus a third product. Also discussed are the room temperature isomerisations observed. Chapter 4 reports the double cage decapitation of 1,1′-bis(o-carborane) and metallation with {(dmpe)Ni} fragments, and discusses diastereoisomers obtained for the first time. Also discussed are the methylation of 1,1′-bis(o-carborane) and the results obtained from decapitation followed by deprotonation and metallation of this. Chapter 5 gives full details of the experimental procedures undertaken and also pro-vides spectroscopic and analytical data for all new compounds reported herein. Appendix 1 provides details of the crystal structure determinations of the compounds synthesised. Appendix 2 (provided on compact disk) gives the appropriate crystallographic files in RTF and CIF format.

Density functional theory (DFT) calculations have been carried out to study the selective C–F bond activation of fluoroaromatics at rhodium and ruthenium complexes. The C–F activation reaction of C6F5H with [Rh(SiR3)(PMe3)3] (R3 = Me2Ph, Ph3) to give [Rh(4-C6F4H)(PMe3)3] and FSiR3, has been studied computationally. Using a model system, [Rh(SiMe3)(PMe3)3], calculations show that the lowest energy process occurs via initial phosphine dissociation and subsequent C–F oxidative addition to give trans-[Rh(4-C6F4H)(F)(SiMe3)(PMe3)2], with computed free energies of activation (∆G‡) of +13.2 kcal/mol and +12.4 kcal/mol, respectively. Reductive elimination and phosphine association to give the final products [Rh(4-C6F4H)(PMe3)3] and FSiMe3 are found to be facile. In addition, calculations show that C–F activation at trans- [Rh(SiMe3)(PMe3)2] is more accessible kinetically and thermodynamically than C–H activation (∆∆G‡ = 2.9 kcal/mol, ∆∆G = 51.3 kcal/mol). DFT calculations have been used to model the reaction of C5NF5 at the 2-position with [Rh(X)(PEt3)3] (X = Si(OEt)3, Bpin, where Bpin = pinacolate = –OCMe2CMe2O–). C–F activation at the computational models [Rh(X)(PMe3)3] (X = Si(OMe)3 and Bpin) shows that the lowest pathways proceed via novel silyl- and boryl-assisted C–F activation in which short RhN contacts are computed in the transition states. These occur via modest barriers (∆G‡ = +26.1 kcal/mol and +20.1 kcal/mol, respectively, relative to the two separated reactants) and also account for the experimental selectivity. The hydrodefluorination (HDF) reaction of C6F5H at [Ru(H)2(CO)(NHC)(PR3)2] (NHC = SIMes, SIPr, IMes, IPr; R = Ph) to give 1,2,3,4-C6F4H2, has been investigated. Calculations on small (NHC = IMe, R = H) and full systems (NHC = IMes, R = Ph) have allowed a novel class of reaction mechanism to be defined involving a nucleophilic attack of one hydride ligand at C6F5H. The most accessible pathway has a computed transition state energy of +20.1 kcal/mol in THF (PCM, approach). In addition, calculations reveal that the use of a more sterically encumbered full model system is essential to explain the unusual ortho-regioselectivity observed experimentally.

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