This thesis mainly concerns the application of electrochemical impedance spectroscopy (EIS) and electrochemical noise analysis (ENA) to the study of CO(subscript)2 corrosion of mild steel and its inhibition. The primary focus is on the use of EIS and ENA to monitor inhibitor film performance and to evaluate inhibitor film persistency.EIS was shown to be a suitable technique to study CO(subscript)2 corrosion product scale, and inhibitor films. The formation and deterioration of protective scales and inhibitor films is found to be accompanied by characteristic spectral changes and a rapid change in electrode impedance. EIS data were used to calculate corrosion related parameters such as the resistances and capacitances of inhibitor layers, and the charge transfer resistance and double layer capacitance. These parameters were used to analyse inhibitor mechanisms, determine corrosion rates and the persistence of inhibitor films.ENA is also a suitable technique to monitor the formation and deterioration of inhibitor films. It has the advantage of being able to monitor rapid processes which occur within one second. Several technical and theoretical developments were made in this thesis including the development of a new method of instantaneous corrosion rate measurement to study fast corrosion processes (the continuous noise resistance calculation method). Experimentally, the noise resistance was confirmed to be similar to linear polarisation resistance in the systems studies. The theoretical background and the advantages and disadvantages of the ENA technique are also discussed.Corrosion product scales formed under different conditions were investigated using EIS and surface analysis techniques. Temperature, pressure and exposure time were confirmed to be the important factors influencing the degree of protection given by the scale. The morphology of corrosion scales ++ / showed an obvious correlation to their protective ability. Electron microscopy revealed two types of crystal structures on corroded steel coupons. The smaller crystals associated with one of these structures was found to contribute most to corrosion protection.Several typical CO(subscript)2 corrosion inhibitors, including an imidazoline and a quaternised amine, were studied by EIS. A multi-layer model was employed to explain the EIS characteristics and self-repairing ability of imidazoline films. A quaternised amine film is most probably a physically or electrostatically adsorbed molecular layer which forms rapidly and desorbs easily.The deterioration of films, formed by commercial batch treatment inhibitors, was found to occur in three stages which were indicated or characterised by Bode phase-angle plots. A method to determine inhibitor film persistency was developed. This method is based on determining the three stages of inhibitor film deterioration, and the continuous measurement of corrosion rate, which is accessible at the second and third stages of film deterioration.

We have synthesized norbornene-functionalized side-chain monomers for potential use as hole transporting and electron transporting/hole blocking materials in organic light-emitting diodes. TPD-norbornenes were prepared. The monomers demonstrated similar electrochemical and absorbance spectra to the parent TPD small molecule. The similarity is promising for using the monomers in OLEDs because TPD is a known blue-emitter with relatively high hole mobility in amorphous thin films. 1,10-Phenanthroline small molecules and monomers were synthesized to explore their potential as hole blocking materials in multilayer devices. We had difficulty purifying the monomers; however, the small molecules were slightly easier to reduce than commonly used hole blocking materials 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline.

Condensation of Ph2PCH2OH with a range of polyaromatic substituted secondary amines afforded a new set of 'hybrid' phosphine ligands of the type {RCH2N(CH2PPh2)CH2}2 and RCH2N(CH2PPh2)CH2CH3 (R = various planar aromatic groups). The coordination chemistry of these new mono and bidentate ligands towards a range of transition metal centres including Mo(0), Au(I), Rh(I), Ni(II), Pd(II), Pt(II) and Ru(II) was investigated. Ditertiary phosphines of the form {RCH2N(CH2PPh2)CH2}2 were found to be capable of bridging two transition metal centres in addition to forming rare examples of nine-membered cis- and trans- chelate complexes. Single crystal X-ray analysis of these coordination compounds revealed several types of inter- and intramolecular packing interactions (including a C-H···Pt interaction and slipped intermolecular π····π stacking), and also confirmed the rare trans-diphosphine coordination mode. Fluorescent emission measurements have been undertaken on these new tertiary phosphines and their coordination compounds, and these luminescent properties are discussed. A preliminary investigation into the chemosensory behaviour of selected compounds has been undertaken. Using RPCH2OH (RP = Ph2P, Cy2P or AdP = 1,3,5,7,-tetramethyl-2,4,8-trioxa-6- phosphaadamantane) as a versatile precursor, a range of ferrocenyl (Fc) tertiary phosphines have been prepared from a selection of primary and secondary amines. The coordination chemistry of these new mono and bidentate ligands towards several transition metal centres including Cr(0), Mo(0), Au(I), Rh(I), Ru(II), Pd(II) and Pt(II) was investigated. In particular, the previous chemistry was expanded to prepare several new diferrocenyl phosphines of the form {FcCH2N(CH2PR)CH2}2. In a similar manner to their polyaromatic counterparts, these ditertiary phosphines were found to be capable of coordination through both bridging and cis- / trans-chelating modes. Notably, single crystal X-ray analysis was used to confirm the formation of an extremely rare example of a dimeric trans, trans-[Rh(CO)Cl{phosphine}2]2 complex; thought to be the first crystallographically characterised metallacycle containing an Rh2Fe4 arrangement of metal centres. In addition to this {FcCH2N(CH2PR)CH2}2 chemistry, a rare example of a triferrocenyl ditertiary ii phosphine, {FcCH2N(CH2PPh2)CH2}2Fc, was prepared, as well as a macrocyclic ditertiary ferrocenyl phosphine, C10H8Fe(CH2N(CH2PPh2)CH2)2CH2. The coordination chemistry of {FcCH2N(CH2PPh2)CH2}2Fc led to the formation of two unusual examples of pentametallic diphosphine coordination complexes with a Fe3Au2 and Fe3Ru2 arrangement of metal centres. The development of a new phosphinoamine, (Ph2P)2NCH2Fc, and a new ferrocenyl iminophosphine, Ph2PCH(Ph)CH2C(H)NCH2Fc, are also discussed, in addition to a brief investigation of their coordination chemistry. Electrochemical measurements have also been undertaken on these ferrocenyl ligands and their respective coordination compounds (when purity, yield and stability would allow), and their redox chemistry discussed. A series of novel phosphorus(III) containing ligands of the forms (R)N(CH2PPh2)2 and (R)NHCOCH2N(CH2PPh2)2 (R = functionalised planar aromatic or ferrocenyl group) have been prepared. The phosphines were found to readily coordinate several transition metals including Pt(II), Pd(II) and Ru(II) to form a series of new cis- chelate and bridged bimetallic complexes. Analysis by single crystal X-ray diffraction revealed several types of inter- and intramolecular hydrogen bonding within the molecular structures of the phosphines and their coordination compounds, including the formation of several intermolecular 1D chains and the presence of an intramolecular N-H···N bond, which forces a 'scorpion-like' conformation.