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Phthalocyanines are a class of compounds intensively studied because of their intense blue/green colour. The discovery, the synthesis and some of their applications are described in Chapter 1. A number of crystal structures have been published in the past. In chapter 2, a comparison study discusses the effect of the substituents (linear such as n-hexyl or branched such as iso-pentyl) and the central ion (zinc, nickel, lead and free base) on molecular structure and packing. Crystal structures have been obtained and a UV-Vis study in solution and in the solid state as well as Non Linear Optical measurements in solution and in the solid state have been carried out. Phthalocyanine arrays containing well-defined scaffolds and support architectures are currently being investigated for NLO, molecular-electronics and sensor-device applications. In two different approaches, the synthesis of oligomeric and macromolecular arrays from a single mono-functionalised phthalocyanine has been investigated. In the first the synthesis was attempted of a well-defined structure of oligomeric polyisocyanide Pc that should arise from the synthesis of a peripheral isocyanide-dipeptide substituent which, when polymerised, should afford a rigid, helical polymeric backbone for the phthalocyanine array. In the second the synthesis was attempted of a hexameric macromolecular species affording a defined macromolecular system designed to exhibit properties mediated by both inter- and intramolecular phthalocyanine interactions. The results are presented together in Chapter 3. Chapter 4 reports the discovery that spin coated films of 1,4,8,11,15,18,22,25- octakis(hexyl)phthalocyaninato lead (Il) can be used as a medium for the source of Pb2 for the formation of PbS nanoparticles when exposed to H2S gas. It has been demonstrated that the formation of CdS nanoparticles can be carried out following the same procedure. The synthesis and characterisation of CdS and PbS nanoparticles is discussed.

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The present study was mainly devoted to evaluate the applicability of differential pulse adsorptive stripping voltammetry (DPAdSV) for the determination of ultra-trace concentration levels of a range of reactive dyes. The studied reactive dyes were found to adsorb effectively onto the hanging mercury drop electrode (HMDE). This applied electroanalytical method was primarily based on the nonelectrolytic accumulation (adsorption) of the analyte of interest (reactive dye), followed by a cathodic reduction scan measurement. Consequently, the adsorptive stripping voltammograms of the analysed reactive dyes exhibited several useful electrochemical signals, corresponding to the cathodic reduction of the anthraquinone, azo and halo-striazine groups.

12 azo dye ligands LI-LI2 that are used in the inkjet printer industry have been synthesised and characterised. The dyes L5B and L3765 were supplied as gifts by the chemical company Avecia. All dyes were fully examined by IH NMR, 13e NMR, IR spectroscopy, electrospray mass spectroscopy, atomic absorption spectroscopy, UV-Visible spectroscopy and microanalyses. Melting points were also determined. pKa values have been determined by visible spectroscopy for the dyes PAN(Aldrich), L7, L3765, Ll, L5 and L5B. Stability constant measurements have been attempted for the Ni(II) complexes of PAN, LI and L5 using UV-Visible spectroscopy. Single wavelength stopped-flow kinetic studies of the reactions of Ni(II) with PAN(Aldrich), PADA(Aldrich), SUDAN I(Aldrich), L3765 and L7 were carried out. Multi wavelength stopped-flow kinetic studies of the reactions of Ni(II) with L 1, L 7, L5 and L5B were examined and rate constants for complex formation (kf ) were determined. Rates of dissociation of [Ni(PAN)2] using ligand exchange with either EDTA or 2,2' :6' ,2" -Terpyridine (Terpy) were investigated using UV -Visible spectroscopy. Relative stabilities of [Ni(II)(PAN)t, [Ni(II)(L 7)] and [Ni(II)(L3765)r have been determined. Dissociation of Ni(II) complexes of Ll, L5, L5B, L6, PAN, L7 and L3765 using excess Terpy have been studied using UV -Visible spectroscopy and relative stabilities have been compared.

Dans cette étude nous avons cherché à évaluer les paramètres et les mécanismes gouvernant la réactivité des catalyseurs à base de cérium lors de la dégradation des colorants textiles, seuls ou en mélange binaire, dans le cadre du procédé Fenton/photo-Fenton. Dans ce but, 5 séries de catalyseurs à base de cérium ont été testées pour déterminer les effets respectifs : (i) de la surface spécifique de CeO2 commercial (SBET = 11, 101,5 ; 148 ; 235 et 284 m2/g), (ii) du dopage au zirconium (oxydes mixtes CexZr1-xO2 avec différentes teneurs en cérium (x = 0 ; 0,2 ; 0,5 ; 0,8 ; 1)), (iii) d’un traitement de sulfatation de CexZr1-xO2 par H2SO4, et (iv) de l’imprégnation de CeO2 par différents métaux (M = Ba, Bi, La, V et Mo). Les propriétés texturales, structurales et chimiques des catalyseurs à base de cérium étudiés ont été dans la plupart des cas caractérisées par porosimétrie à l’azote, DRX, Raman, XPS, FTIR/ATR, DR-UV-Vis et ATG. Les cinétiques de décoloration et de minéralisation de l’Orange II en présence de CeO2 et H2O2 dépendent fortement de la surface spécifique des catalyseurs ainsi que des paramètres opératoires (présence d’irradiation UV-Vis, pH, température, concentration initiale en catalyseur et en H2O2). Par comparaison avec les colorants pris séparément, l’adsorption compétitive de l’Orange II et de l’Acide Vert 25 sur les mêmes sites d’adsorption à pH = 3 réduit les taux de dégradation des deux colorants en mélange. En revanche, l’association de l’Orange et du Vert de Malachite en paires d’ion, permet d’améliorer la cinétique apparente de dégradation du Vert de Malachite d’un facteur 5. Dans ce cas, la réaction de Fenton et la coagulation-floculation contribuent simultanément à l’élimination de deux colorants de charge opposée en présence du système CeO2/H2O2. De plus, les performances des oxydes mixtes Ce-Zr dans le procédé Fenton hétérogène sont étroitement liées à leurs caractéristiques texturales, structurales et chimiques. Les analyses effectuées ont permis de vérifier les phases cristallines des oxydes mixtes de révéler la formation de solutions solides. Le traitement de sulfatation conduit à la diminution de la surface spécifique et l’augmentation de la taille des cristallites des oxydes riches en Ce. La dissolution de CeO2 lors de sulfatation suivie par formation d’une phase amorphe Ce(SO4)2 à la surface du catalyseur a été mise en évidence. Le traitement de sulfatation ainsi que le dopage au Zr permettent d’augmenter la densité de surface en sites réduits Ce(III). Les études en spectroscopies DR-UV-Vis, FTIR/ATR et Raman relatives à l’adsorption et l’activation d’H2O2 par les oxydes mixtes ont permis de mettre en évidence l’existence d’espèces Ce-peroxo de surface, comme intermédiaires pour générer les radicaux hydroxyles. La détermination quantitative de ces espèces par TPD-MS s’est avérée utile pour mieux comprendre les performances catalytiques des oxydes mixtes modifiés ou non. La concentration en Ce de surface, la densité de défauts Ce(III) (augmenté par dopage et le traitement de sulfatation) et la surface spécifique semblent être à cet égard parmi les paramètres les plus influents sur l’activité. L’imprégnation de CeO2 par différents métaux n’a pas montré un impact positif sur la réactivité de ce matériau en procédé Fenton. Un mécanisme général d’activation d’H2O2 a été proposé sur la base des résultats expérimentaux obtenus et la littérature. De point de vue mécanistique, les analyses spectroscopiques par ATR/FTIR et UV-Vis montrent que l’adsorption de l’Orange II à la surface du catalyseur est fortement dépendante du pH du milieu et se fait par des interactions électrostatiques. Le mécanisme de dégradation de l’Orange II, en phase liquide et à la surface du catalyseur, a été étudié par différentes techniques (DR-UV-VIS et ATR/IR, HPLC et GC/MS) / In this work, the parameters and mechanisms governing the reactivity of cerium based materials towards the degradation of textile dyes, taken separately or in binary mixture, in Fenton/photo-Fenton process have been investigated. For this purpose, five sets of catalysts were performed in order to determine the respective effects of : (i) the specific surface area of commercial CeO2 (SBET = 11, 101,5 ; 148 ; 235 and 284 m2/g); (ii) the zirconia doping ((CexZr1-xO2 with different Ce content (x = 0 ; 0,2 ; 0,5 ; 0,8 ; 1)); (iii) the treatment with H2SO4 ; and (iv) the impregnation of different metals in CeO2 (M = Ba, Bi, La, V and Mo). The textural, structural and chemical properties of the studied ceria-based materials were systematically characterized by nitrogen porosimetry, Raman, XRD, XPS, ATR/FTIR, DR-UV-Vis and TGA. Discoloration and mineralization kinetics of Orange II dye in presence of CeO2/H2O2 system are strongly related to the surface area of catalysts and other parameters (UV-Vis irradiation, pH, temperature, concentration of catalyst and H2O2). The presence of another dye with similar (Acid Green 25) or opposite charge (Malachite Green) can also influence the discoloration kinetics of Orange II. Comparing with single dye solutions, the degradation efficiency of both Orange II and Acid Green 25 were reduced in the mixture due to the competitive adsorption of both anionic dyes onto the same surface Ce sites. However, the discoloration of Malachite Green was enhanced in the presence of Orange II due to the simultaneous contribution of both coagulation/flocculation and Fenton-like process. It is suggested that a Malachite Green ion is electrostatically attracted by an Orange II ion at pH = 3. In addition, the performance of the mixed oxides in the heterogeneous Fenton process is strongly related to their textural, structural and chemical properties. Briefly, characterizations by XRD and Raman spectroscopy indicate that these nanosized mixed oxides can be considered as good quality solid solutions and possess structural properties consistent with the known phase diagram of CexZ1-xO2. The sulfation treatment mostly affects the Ce rich catalysts by increasing the crystallite size and lowering the specific surface area. The dissolution of ceria during sulfation followed by formation of Ce(SO4)2 amorphous phase on catalyst surface was investigated by UV-Vis and TGA analysis. Sulfation treatment as well as doping ceria with Zr increases the amount of reduced sites Ce (III) and defect sites.DR-UV-Vis, FTIR/ATR and Raman spectroscopic studies for adsorption and activation of H2O2 on mixed oxides show the formation of surface Ce-peroxo species as intermediate to generate hydroxyl radicals. The relative amounts of these species on the mixed oxides and/or not modified was indirectly determined using TPD-MS, giving rather good indication about the performances of catalysts towards the degradation of dye. The concentration of surface Ce, the density of defects Ce(III) sites (increased by doping and sulfation treatment) and the surface area appear to be among the most important parameters affecting the catalytic activity. Impregnation of ceria with different metals did not show a positive effect on the reactivity of this material in Fenton process. A possible mechanism for the activation of H2O2 was discussed in details according to all the experimental results and to the literature. From a mechanistic viewpoint, it is shown using FTIR/ATR and liquid UV-Vis spectroscopic measurements that the adsorption of the anionic dye is highly pH-dependent and proceeds via electrostatic interactions with surface metal centers. A possible pathway for Orange degradation is proposed on the basis of qualitative and quantitative detection of intermediate compounds, in liquid phase and on catalyst surface, using various techniques (FTIR/ATR, DR-UV-VIS, HPLC and GC/MS)