The work described in this thesis concerns the synthesis and study of the coordination behaviour of the 6-anilino-2,2'-bipyridyl (Habipy), 6-N-methylanilino-2,2'-bipyridyl (mabipy), 6-piperidyl2,2'.- bipyridyl (pipbipy) and 2,2'-bipyridin-6-one (Hobipy) ligands. Chapter one reviews the coordination chemistry of the 2-aminopyridyl (Rap), 2-hydroxypyridyl (Hhp) and the 2-(2-pyridyl)-I,8-naphthyridine (pynp) ligands. These ligands are closely related to Habipy, mabipy, pipbipy and Hobipy in that they share a common NCN or NCO fragment. Thus the review of their coordination behaviour provides insight into the expected coordination of the Habipy, mabipy, pipbipy and Hobipy ligands. The synthesis and characteristaion of the novel Habipy, mabipy and pipbipy ligands are reported in Chapter two. X-ray crystal structure determinations of mabipy and pipbipy reveal that the geometry about the exocyclic nitrogen atom in both ligands is nearly planer, suggesting substantial overlap of the nitrogen lone pair orbital with the 1t electron system of the bipyridyl rings. In both mabipy and pipbipy the N3-C 10 bond lengths are shorter then normal N-C single bonds. In Chapter three -the synthesis and characterisation of copper(I) complexes containing mabipy, pipbipy and Habipy, and a copper(II) complex containing mabipy are reported. The copper(I) complexes have the general formula [Cu(l12-L)2r, where L= mabipy 1, pipbipy 2 or Habipy 3. The structures of complexes 1 and 2 are determined by X-ray crystallography. In complexes 1- 3 the bipyridyl fragments of mabipy, pipbipy and Habipy chelate while the exocyclic nitrogen atoms remain free. The crystal structures of 1 and 2 reveal that the exocyclic nitrogens have a planar geometry as was the case in the uncoordinated ligand. The crystal structure of [Cu(1l2-mabipY)2f+ (4) is determined by X-ray crystallography and is very similar to that of the copper(I) species. Coordination of the mabipy ligand in 4 is the same as that in 1 and the exocyclic nitrogen in 4 is also planar. The redox couple 4/1 is shown to be electrochemically reversible with EV2= 0.45 V. In Chapter four the synthesis and chararcterisation of dinuclear complexes containing the Ru2 2+, Ru/+, Mo24+and ~4+ cores are reported in which the abipy ligand bridges two metal centres. The complexes [Rulll-L)lCO)4], where L= abipy 5 or obipy 6, were synthesised by the r~action of the free ligands with [{RuiCO)102CCH3)2}n] in toluene. The structures of5 and 6 are determined by X-ray crystallography and show the ligands bridging the Ru(I) atoms in a head to tail fashion and occupy mutually cis positions about the octahedral Ru(I) atoms. The Ru-Ru separations in 5 and 6 are 2.668(1) and 2.671(1) A respectively. The reaction of Habipy with [Rui02CCH3)4CI]n was found to afford the mixed valence species [Ruill-abipy)(02CCH3)3CI] (7), the structure of which is determined by X-ray diffraction methods. The structure of7 reveals one abipy ligand bridging the two ruthenium atoms as in 5. The Ru-Ru separation in 7 is 2.294(2) A. The reaction of [Moi02CCH3)4] with habipy in methanol affords (Moill-abipy)(02CCH3)3] (8). The structure of 8 is determined by X-ray diffraction methods and reveals one abipy ligand bridging two quadruply bonded molybdenum atoms which have a Mo-Mo separation of 2.094(2) A. The [Rhlll~abipy)(02CCH3)iH20)] (9) is formed from the reaction of [Rh i02CCH3)4] with Habipy in methanol. The structure of [Rh2(Il-abipy)(02CCH3)iNCPh)] is determined by X-ray diffraction methods and shows the abipy ligand bridging two Rh(II) atoms which are separated by 2.399(1) A. This chapter is concluded with a discussion of the possiblity of substitution of more than one acetate ligand by the abipy ligand in terms of 'hard' and' soft' acid-base theory and synthetic methods. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

A series of Pt(S₂N₂)(P(OR)[subscript n]R′[subscript(3-n)])₂ complexes were prepared and analysed using ³¹P NMR and IR spectroscopy, elemental analysis and X-ray crystallography. Similarly, a series of Pt(SeSN₂)(P(OR)[subscript n]R′[subscript(3-n)])₂ complexes were also prepared and analysed. The ¹J[subscript(Pt-P)] coupling constants and Pt-P bond lengths for these complexes are influenced by the oxygen content of their phosphorus ligands. The ³¹P NMR spectra for a series of [Pt(S3N)(P(OR)[subscript n]R′[subscript(3-n)])₂][BF₄] complexes are also reported. Planar [S₂N₂H]⁻ complexes were prepared and the X-ray crystal structure of [Pd(S₂N₂H)(bipy)][Cl] is reported. The X-ray structures of MX₂(P(OR)[subscript n]R′[subscript(3-n)])₂ are reported and compared with the previously reported analogues. The magnitude of the ¹J[subscript(Pt-P)] varies linearly with the Pt-P bond length (l[subscript(Pt-P)] = 2.421 – J/24255) for the 12 platinum-containing complexes. This correlation is compared to that of a larger series of complexes. A series of M(ndsdsd₂ (ndsdsd = bis[(nitrilo(diphenyl)-λ⁶-sulfanyl)](diphenyl)-λ⁶-sulfanediimide (Ph₂S(=N-(Ph₂)S≡N)₂)) complexes were prepared and characterised using elemental analysis and multinuclear NMR and IR spectroscopy where appropriate. The X-ray crystal structures of five examples are reported.

Title: Symmetrical aminophosphinates Author: Bc. Soňa Procházková Department of Inorganic Chemistry, Faculty of Science, Charles University Supervisor: RNDr. Vojtěch Kubíček, Ph.D. Supervisor's email address: kubicek@natur.cuni.cz ABSTRACT Two types of α-aminophosphinates were prepared and studied: phosphinate analogues of iminodiacetic acid − aminobis(methyl(hydroxymethyl)phosphinic acid) (IDPhm ) and aminobis(methyl(2-carboxyethyl)phosphinic acid) (IDPce ), and bis(aminomethyl- phosphinates) − (hydroxy(fenyl)methylen)bis(aminomethylphosphinic acid) (PheOHABPin) and (methylen)bis(aminomethylphosphinic acid) (ABPin). All prepared compounds were fully characterized (by NMR, MS, elemental analysis). One crystal structure was determined by X-ray singlecrystal analysis. The diphosphinates were synthesized by Mannich type reaction, whereas the bis(aminomethylphosphinates) were prepared by multistep synthesis including reactive silylesters. Compounds were prepared in moderate or good yields Acid-base and coordination properties of ligands were investigated and compared by potentiometric and NMR titrations. The values of protonation constants of aminogroups, which determine stability of complexes, showed surprising results. An extremely low basicity of nitrogen atom was found in diphosphinates. So, these compounds...

A combined experimental and computational study on the reversible ortho-metalation exhibited by the triosmium cluster Os3(CO)10(dppm) (dppm = 1,1-bis(diphenylphosphino)methane is reported. The conversion of nonacarbonyl cluster HOs3(CO)9[-PhP(C6H4)CH2PPh2] to Os3(CO)10(dppm) is independent of added CO and exhibits a significant inverse equilibrium isotope effect (EIE). Reductive coupling of the C-H bond in HOs3(CO)9[-PhP(C6H4)CH2PPh2] leads to the formation of agostic C-H and two distinct aryl-π species prior to the rate-limiting formation of the unsaturated cluster Os3(CO)9(dppm). Heating the unsaturated dimer H2Re2(CO)8 with Cp*Rh(CO)2 (Cp* = 1,2,3,4,5-pentamethylcyclopentadiene) at elevated temperature affords the new trimetallic clusters H2RhRe2Cp*(CO)9 and HRh2ReCp*2(CO)6, and the spiked-triangular cluster HRhRe3Cp*(CO)14. H2Re2(CO)8 reacts with Cp*2Rh2(CO)2 under identical conditions to furnish H2RhRe2Cp*(CO)9 and HRh2ReCp*2(CO)6 as the principal products, in addition to the tetrahedral cluster H2Rh2Re2Cp*2(CO)8. H2RhRe2Cp*(CO)9 undergoes facile fragmentation in the presence of halogenated solvents and the thiols RSH (where R = H, C6H4Me-p) to afford the structurally characterized products Cp*Rh(-Cl)3Re(CO)3, S2Rh3Cp*(CO)4, Cp*Rh(-Cl)(-SC6H4Me-p)2Re(CO)3, and Cp*Rh(-SC6H4Me-p)3Re(CO)3. The new hydrazido-substituted compounds TaCl(NMe2)3[N(TMS)NMe2] (TMS = tetramethylsilyl) and Ta(NMe2)4[N(TMS)NMe2] have been synthesized and their structures established by X-ray crystallography. The latter product represents the first structurally characterized octahedral tantalum(V) complex containing a single hydrazido(I) ligand in an all-nitrogen coordinated environment about the metal center. The fluxional properties of the amido and hydrazido ligands in these new compounds have been established by VT 1H NMR spectroscopy (VT = variable temperature). Preliminary data using Ta(NMe2)4[N(TMS)NMe2] as an ALD (ALD = atomic layer deposition) precursor for the preparation of tantalum nitride and tantalum oxide thin films are presented.

Reductive functionalization of methyl ligands by 3d metal catalysts and two possible side reactions has been studied. Selective oxidation of methane, which is the primary component of natural gas, to methanol (a more easily transportable liquid) using organometallic catalysis, has become more important due to the abundance of domestic natural gas. In this regard, reductive functionalization (RF) of methyl ligands in [M(diimine)2(CH3)(Cl)] (M: VII (d3) through CuII (d9)) complexes, has been studied computationally using density functional techniques. A SN2 mechanism for the nucleophilic attack of hydroxide on the metal-methyl bond, resulting in the formation of methanol, was studied. Similar highly exergonic pathways with very low energy SN2 barriers were observed for the proposed RF mechanism for all complexes studied. To modulate RF pathways closer to thermoneutral for catalytic purposes, a future challenge, paradoxically, requires finding a way to strengthen the metal-methyl bond. Furthermore, DFT calculations suggest that for 3d metals, ligand properties will be of greater importance than metal identity in isolating suitable catalysts for alkane hydroxylation in which reductive functionalization is used to form the C—O bond. Two possible competitive reactions for RF of metal-methyl complexes were studied to understand the factors that lower the selectivity of C—O bond forming reactions. One of them was deprotonation of the methyl group, which leads to formation of a methylene complex and water. The other side reaction was metal-methyl bond dissociation, which was assessed by calculating the bond dissociation free energies of M3d—CH3 bonds. Deprotonation was found to be competitive kinetically for most of the 1st row transition metal-methyl complexes (except for CrII, MnII and CuII), but less favorable thermodynamically as compared to reductive functionalization for all of the studied 1st row transition metal complexes. Metal-carbon bond dissociation was found to be less favorable than the RF reactions for most 3d transition metal complexes studied. The first dinitrogen dicopper (I) complex has been characterized using computational and experimental methods. Low temperature reaction of the tris(pyrazolyl)borate copper(II) hydroxide {iPr2TpCu}2(µ-OH)2 with triphenylsilane under a dinitrogen atmosphere gives the µ -N2 complex, {iPr2TpCu}2(µ -N2). X-ray crystallography reveals an only slightly activated N2 ligand (N-N: 1.111(6) Å) that bridges between two iPr2TpCuI fragments. While DFT studies of mono- and dinuclear copper dinitrogen complexes suggest a weak µ-backbonding between the d10 CuI centers and the N2 ligand, they reveal a degree of cooperativity in the dinuclear Cu-N2-Cu interaction.

Orientador: José Clayston Melo Pereira / Banca: Adelino Vieira de Godoy Netto / Banca: Gustavo Metzker / Resumo: O câncer é uma dos principais problemas de saúde que afeta e mata milhões de pessoas. Diversos tipos de tratamento já foram propostos, entretanto, alguns se apresentam muitas vezes tóxicos ao corpo e/ou ineficientes de acordo com as características particulares do organismo. Dentre as propostas de tratamento está o uso do complexo precursor [Fe(NO)2(CO)2] para síntese de complexos [Fe(NO)2 Ligante] em que se encontram a vanilina tiossemicarbazona (VTS) e a vanilina semicarbazona (VSC) como ligantes. Busca-se, por meio desses, a possibilidade de inibição do sistema enzimático da glutationa - glutationa / glutationa transferases - conhecido por restringir a ação da cisplatina através da catalisação da conjugação da glutationa com o complexo - e através do uso dos dinitrosilos de ferro (DNICs) e da liberação do ligante orgânico obter uma possível atuação farmacológica. Neste trabalho, foram utilizadas técnicas como Análise Elementar, Espectroscopia no UV-Vis, Espectroscopia no Infravermelho, Espectroscopia de Ressonância Magnética Nuclear, Ressonância Paramagnética de Elétron e Espectrometria de Massas para a caracterização dos ligantes que foram também avaliados por ensaio citotóxico frente a linhagem MCF-7 (adenocarcinoma mamário humano) e bacteriano por Staphylococcus aureus e Escherichia coli. Os complexos sintetizados foram avaliados por técnicas espectroscópicas e espectrometria de massas. / Abstract: Cancer is one of the major health problems that affects and kills millions of people. Several types of treatment have been proposed, however, some of them are often toxic to the body and / or inefficient according to the particular characteristics of the organism. Among the treatment proposals is the use of the precursor complex [Fe(NO)2(CO)2] for synthesis of complexes [Fe(NO)2Binder] in which are the vanillin thiosemicarbazone (VTS) and vanillin semicarbazone (VSC ) as ligands. The aim is to inhibit the enzymatic system of glutathione glutathione / glutathione transferases known to restrict the action of cisplatin by catalyzing the conjugation of glutathione to the complex and through the use of iron dinitrosilos (DNICs) and the release of the organic ligand to obtain a possible pharmacological action. In this project, were used techniques such as Elementary Analysis, UV-Vis Spectroscopy, Infrared Spectroscopy, Nuclear Magnetic Resonance Spectroscopy, Electron Paramagnetic Resonance and Mass Spectrometry for the characterization of ligands that were also evaluated by cytotoxic assay against the MCF lineage -7 (human mammary adenocarcinoma) and bacterial by Staphylococcus aureus and Escherichia coli. The synthesized complexes were evaluated by spectroscopic techniques and mass spectrometry. / Mestre

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Contamination of water bodies by heavy metals and metalloids is an established problem and several studies have been conducted to deal with it. South Africa is amongst those countries whose water systems are most affected as a result of intensive mining activities. This research was dedicated to the development of insoluble chelating polymers for use as adsorbents to abstract heavy metal ions from mining and industrial wastewater. Branched polyethylenimine (PEI), well known for its metal chelating potential, was cross linked by epichlorohydrin in order to convert it into a water-insoluble form. The water-insoluble property gives the advantage of being used in situ and a possibility of regeneration and re-use, making it a more feasible and cost-effective method. Its surface was also modified for selective removal of specifically-targeted heavy metal and metalloid ions. The binding affinity of the synthesized materials to heavy metal and metalloid ions has been determined as well as their ability to be regenerated for reuse. These processes demonstrated that cross-linked polyethylenimine (CPEI) exhibited good complexation ability with high affinity to Cr and some divalent metal ions such as Fe, Zn, and Ni. On the other hand, it showed very poor ability to bind oxo-anions such as SeO32- and AsO2- which has been attributed to the unavailability of suitable functional groups to interact with these ions. The observed order of complexation was: Cr > Zn> Fe >> Ni > Mn > Pb >> As > U > Se. The phosphonated polyethylenimine (PCPEI) showed high selectivity for As, Mn and uranyl ions. The observed order of removal was: U > Mn> Ni > Zn > As >> Cr > Pb > Fe >> Hg > Se; whereas the suffocated polyethylenimine (SCPEI) exhibited high affinity to Se, and Hg. The observed order of adsorption was: Hg > Se >> U > Zn >Pb > Ni >> As > Cr > Fe. v The adsorption behaviour of these polymeric materials involved more than one mechanism such as complexation, normal surface charge exchange, and anion replacement and all these mechanisms are governed by the functional groups. The nitrogen atom on the chelating group (-NH) in the cross-linked polyethylenimine; the phosphorus atom on the chelating group (-PO3H2) in phosphonated cross-linked polyethylenimine; and sulphur atom on the chelating group (-SO3H) in suffocated cross-linked polyethylenimine act as Lewis bases and donate electrons to metal cations which are considered Lewis acids. The existence of the chelating groups in SCPEI and PCPEI facilitate the removal of oxo-anions through anion replacement since they exist as bases in solution and hence cannot be electron acceptors. Thus, the expected mechanism is the normal anion replacement. This mechanism can explain the high removal of Se by SCPEI since Se has similar chemical behaviour as sulphur and are in the same group in the periodic table. As such they can easily replace each other. Sulphur is released from the polymer into the solution by replacing the selenium ions in the polymer. Similar behaviour occurs between phosphorus in PCPEI and arsenic ions as As and P belong to the same group in the periodic table and hence have similarities in their chemical behaviour. The Langmuir and Freundlich isotherm models were used to interpret the adsorption nature of the metal ions onto synthesized polymers. The Freundlich isotherm was found to best fit and describe the experimental data describing the adsorption process of metal and metalloid ions onto the synthesized polymeric materials The kinetic rates were modelled using the pseudo first-order equation and pseudo second-order equation. The pseudo second-order equation was found to explain the adsorption kinetics most effectively implying chemisorption. vi The thermodynamic study of the adsorption of metals and metalloids by the synthesized CPEI, PCPEI and SCPEI resulted in high activation energies > 41 KJ mol-1 which confirm chemisorption as a mechanism of interaction between adsorbate and adsorbent. So far, the developed polymeric materials showed good results and have potential to be applied successfully for remediation of heavy metal-polluted waters, and they have potential for use in filter systems for household use in communities that use borehole water impacted by mining and industrial waste waters. The desorbed metals can be of use to metal processing industries.

A soja é uma leguminosa amplamente cultivada mundialmente, sendo o Brasil o segundo maior produtor mundial. Seu alto conteúdo proteico e baixo custo são fatores potenciais para o desenvolvimento de produtos tendo como base o isolado proteico de soja ou seus derivados. Neste sentido, a partir do farelo de soja (após extração do óleo) e métodos convencionais de extração foi obtido o concentrado proteico, substrato para o desenvolvimento de hidrolisados enzimáticos parciais de proteína. Para tanto, foram avaliadas endopeptidases (Neutrase® 0,8L, Alcalase® 2,4L e papaína) e exopeptidase (Flavourzyme® 1000L). A partir do hidrolisado foram preparados complexos/quelatos de metal-peptídeo. Em cada etapa foi avaliada a viabilidade econômica do produto gerado. A condição de extração proteica que proporcionou o melhor resultado foi a relação sólido/solvente de 1:30 (m/v), pH 9,0 ajustado com NaOH 4,0 M, com tempo de extração de 45 minutos, seguido de filtração e ajuste do pH para 4,5 com HCl 2,0 M para a precipitação de proteínas. Nestas condições foi obtido rendimento aproximado de 68,6 % de extrato com teor proteico de 84 %. O processo de hidrólise que proporcionou melhor perfil de peptídeos foi obtido com a Alcalase® 2,4L, cuja relação proteína/enzima foi de 7,5 mg:10 ?L, com tempo de incubação de 30 minutos em solução de tampão fosfato de sódio 30 mM a 55 ºC. Porém, não foi possível a secagem do hidrolisado devido ao teor de glicerol oriundo da enzima. Este inconveniente foi superado com a purificação parcial da mistura enzimática em coluna de Sephadex G25, eluída com tampão acetato de sódio (50 mM, pH 5,0), obtendo assim o concentrado enzimático sem prejuízo para a atividade da enzima. O hidrolisado assim obtido representa a proteína em seu conteúdo de aminoácido tanto qualitativamente quanto quantitativamente. Na preparação dos complexos metálicos de cobre, ferro, zinco e manganês, o ponto de equivalência metal/ligante foi determinado com a utilização de métodos eletroquímicos (voltametria cíclica ou titulação potenciométrica) e a quantificação do metal por absorção atômica revelou uma quantidade de metal ligado de 15,19; 5,55; 3,13 e 2,94 % de manganês, ferro, cobre e zinco respectivamente. A análise econômica mostrou a viabilidade para a produção de complexo de zinco, porém não se descartou a viabilidade dos outros produtos mediante ao ajuste da escala produtiva. / The soybean is a legume widely cultivated worldwide, with Brazil being the second largest world producer. Its high protein content and low cost are potential factors for the development of products based on isolated soybean protein or its derived products. In this way, from the soybean meal ( after oil extraction ) and conventional extraction methods, the protein concentrate was obtained, which is a substrate for the development of partial hydrolysates of protein. For this, were evaluated endopeptidases (Neutrase® 0.8L, Alcalase® 2.4L and papain) and a exopeptidase (Flavourzyme® 1000L). From the hydrolysate were prepared metal-peptide complexes / chelates. At each stage were evaluated the economic feasibility of the generated product. The protein extraction condition which provided the best result was the relationship solid/solvent 1:30 (w/v), pH 9.0 adjusted with 4.0 M NaOH, with extraction time of 45 minutes, followed by filtration and pH adjustment to 4.5 with 2.0 M HCl for proteins precipitation. In these conditions was obtained an income of about 68.6 % of extract with 84% of protein content. The hydrolysis process which provided the best peptides profile was obtained with Alcalase® 2.4L, whose ratio of protein / enzyme was 7.5 mg:10 ?L, with incubation time of 30 minutes in a buffer solution of sodium phosphate 30 mM at 55 º C. However, the drying of the hydrolyzed was not possible due to the glycerol content coming from the enzyme. This drawback was overcome by partial purification of the enzyme mixture on a column of Sephadex G25, eluted with sodium acetate buffer (50 mM, pH 5.0), thus obtaining the enzymatic concentrate without any loss to the enzyme activity. The thus obtained hydrolysate represents the protein in its amino acid content qualitatively and quantitatively. In the preparation of metal complexes of copper, iron, zinc and manganese, the equivalence point metal / ligand was determined using electrochemical methods (cyclic voltammetry or potentiometric titration) and metal quantification by atomic absorption revealed an amount of bounded metal of the 15.19; 5.55; 3.13 e 2.94 % of manganese, iron, copper and zinc respectively. The economic analysis showed the feasibility for the production of zinc complex, but not dismissed the feasibility of using the other products adjusting the scale of production.

O objetivo principal deste trabalho é aplicar complexos de cobre(II), níquel(II), zinco(II) e nióbio(V) como fontes de metais em banhos de eletrodeposição. Os íons metálicos foram coordenados aos ligantes íon oxalato, íon citrato, etilenodiamina (EDA) ou tetraetilenopentamina (TEPA), os quais são aditivos orgânicos típicos em banhos de eletrodeposição. Os complexos foram caracterizados por análise elementar, espectroscopias nas regiões do infravermelho e ultravioleta-visível e voltametria cíclica. Foram realizadas eletrólises em presença de dois complexos de coordenação em ausência de quantias adicionais de aditivos, usando aço 1010 como substrato a pH = 4.5 (H2SO4/Na2SO4), resultando em depósitos com dois elementos metálicos. Os depósitos apresentaram aspectos morfológicos com boas qualidades e sem falhas. Em adição, os depósitos foram analisados por EDX, reflectância difusa e espectroscopia de raio-X e também foram realizadas medidas de curvas de polarização. Os depósitos obtidos a partir dos complexos gerados ex-situ mostraram morfologias melhores do que depósitos obtidos de soluções preparadas com os sais dos metais na presença dos aditivos, mediante as mesmas condições de trabalho. É sugerido que os metais de partida, coordenados a aditivos influenciam o processo de eletrodeposição, propiciando depósitos com potenciais de corrosão deslocados por até +200 mV em 0.5 mol.L-1 NaCl (1 mV.s-1). / The main goal of this work is to use copper(II), nickel(II), zinc(II) and niobium(V) complexes as metal plating source in electrodeposition baths. The metal ions were coordinated with oxalate, citrate, ethylenediamine (EDA) or tetraethylenepentamine (TEPA) as ligands, which are typical organic additives in electroplating. The complexes were characterized by elemental analysis, infrared and ultraviolet spectroscopies and cyclic voltammetry. The electrolyses in presence of two coordination complexes in the baths were carried out in absence of extra amount of additive, using 1010 steel as substrate at pH = 4.5 (H2SO4/Na2SO4). Deposits with two metal elements from the ex-situ generated complexes showed good quality morphologic aspect without crashes. Further, the deposits were analyzed by EDX, diffuse reflectance and X-ray spectroscopy and polarization curves were recorded. The deposits showed better morphologies than deposits obtained from the metal salt solutions in presence of additives under similar conditions. It is suggestive that the starting metal plating coordinated with additives influences the electrodeposition processes, affording deposits with corrosion potentials shifted over +200 mV in 0.5 mol.L-1 NaCl (1 mV.s-1).

The present research work focuses on the coordination chemistry of two different types of monoanionic nitrogen-coordinating ligands, namely the bidentate triazenide ligand [(DippN)N(NDipp)]⁻ (Dipp = Prⁱ₂C₆H₃−2,6) (L¹) and monodentate arylamido ligands [N(R)(Ar)]⁻ (R = SiMe₃., Ar = C₆H₃Me₂-2,6 (L²), C₆H₂Me₃-2,4,6 (L³) or C₆H₃Prⁱ₂-2,6 (L⁴); R = SiBuᵗMe₂, Ar = C₆H₃Prⁱ₂-2,6 (L⁵)). The first part of this work was centred on the synthesis, structural characterization and reactivity of divalent lanthanide metal complexes derived from the triazenide ligand L¹. The second part of this work dealt with the chemistry of low valent and low-coordinate first row transition metal complexes supported by arylamido ligands Lⁿ (n = 2-5). The last part of this work focused on the synthesis and structures of divalent chromium complexes derived from the L¹, L⁴ and L⁵ ligands. / Chapter 1 presents an overview on divalent lanthanide complexes derived from nitrogen-coordinating ligands. The coordination chemistry of low valent and low-coordinate first-row transition metal complexes was also reviewed. / Chapter 2 describes the preparation and characterization of samarium(II) triazenide complex [Sm(L¹)₂(THF)₂] (2). Complex 2 was prepared by the reaction of SmI₂(THF)₂ with 2 equivalents of potassium triazenide [KL¹(THF)₀.₅] (1). The electrochemistry of 2 in THF was studied with cyclic voltammetry. Complex 2 is a strong reducing reagent. Its reactions with various inorganic/organic substrates have been examined. Treatment of 2 with AgCl or PhCH₂Cl gave Sm(III) bis(triazenide) chloride complex [Sm(L¹)₂Cl(THF)₂] (3), whilst reaction of 2 with I₂ led to the isolation of the iodide complex [Sm(L¹)I₂(THF)₃] (4). Reactions of 2 with PhEEPh (E = S, Se) afforded the corresponding Sm(III) chalcogenolate complexes [Sm(L¹)₂(EPh)(THF)] (E = S (5), Se (6)). On the other hands, addition of 2 to ArEEAr (Ar = Buᵗ₂C₆H₃−2,6, E = S, Se and Te) yielded the homoleptic Sm(III) tris(triazenide) complex [Sm(L¹)₃] (7) as the only isolable product. Besides, reactions of 2 with O₂, S₈, Se, Ph₃P=Se and BuᵗOOBuᵗ also yielded complex 7. Complex 2 reacted with PhNHNH₂ and PhNHNHPh, leading to the isolation of the corresponding Sm(III) phenylhydrazido complexes [Sm(L¹)₂(DMAP)₂(NH₂NPh)] (8) and [Sm(L¹)(THF)(μ-η²:η²-PhNNPh)]₂ (9). Reactions of 2 with azobenzene, benzophenone, 9-fluorenone, adamantyl azide, N, N’-dicyclohexylcarbodiimide, N, N’-diisopropylcarbodiimide, and CS₂ were examined as well. / Chapter 3 reports on the coordination chemistry of the triazenide ligand L¹ with divalent ytterbium and europium ions. Metathetical reaction of LnI₂(THF)₂ (Ln = Yb, Eu) with two molar equivalents of [Na(L¹)(THF)₃] (10) led to the corresponding divalent lanthanide(II) bis(triazenide) complexes [Eu(L¹)₂(THF)₂] (11) and [Yb(L¹)₂(THF)₂] (12). The heteroleptic ytterbium(II) complex [Yb(L¹)(μ-I)(THF)₂]₂.(C₆H₁₄) (13.C₆H₁₄) was also isolated along with 12. Oxidation of 12 with CuCl afforded Yb(III) triazenide−chloride complex [Yb(L¹)₂Cl(THF)₂] (14). Treatment of 12 with PhEEPh (E = S, Se) afforded the corresponding Yb(III) chalcogenolate complexes [Yb(L¹)₂(EPh)(THF)] (E = S (15), Se (16)). Nevertheless, reactions of 12 with elemental sulfur and selenium yielded the homoleptic Yb(III) complex [Yb(L¹)₃] (17) as the only isolable product. / Chapter 4 deals with the synthesis and characterization of low valent and low-coordinate first row transition metal complexes derived from arylamido ligands L²-L⁵. Reaction of MCl₂ (M = Fe, Co) with one molar equivalent of lithium amide [Li(L³)(TMEDA)] (TMEDA = Me₂NCH₂CH₂NMe₂) yielded the corresponding monoamido complexes [M(L³)Cl(TMEDA)] (M = Fe (20) and Co (22)). Reduction of [Co(L²)Cl(TMEDA)] (21), 22 and [Co(L³)Cl(TMEDA)] (23) with potassium metal gave the corresponding cobalt(I) amido complexes [CoL²]₂ (24), [CoL₃]₂ (25) and [CoL⁴]₂ (26), respectively. Meanwhile, treatment of [Fe(L⁴)Cl(TMEDA)] (23) with potassium metal yielded iron(I)-dinitrogen complex [{FeL⁴(TMEDA)}₂(μ-η¹:η¹-N₂)] (27). Complexes 24-27 were fully characterized by X-ray crystallography, various spectroscopic techniques and cyclic voltammetry. DFT calculations were carried out in order to understand the electronic structures of these complexes. / Chapter 5 describes the preparation and characterization of three neutral two-coordinate first row transition metal complexes of the general formula [M(L⁵)₂] (M = Fe (29), Co (30), Ni (31)). They were prepared by the reactions of anhydrous MCl₂ (M = Fe, Co) or NiBr₂(DME) with [LiL⁵(Et₂O)₂] (28). The solid-state structures of complexes 29-31 were determined by X-ray diffraction analysis. They were also characterized by spectroscopic methods (UV/Vis, I.R.) and electrochemistry. TD-DFT computational analysis was carried out in order to assign UV/Vis spectra features of these two-coordinate late transition metal (Fe->Ni) complexes. / Chapter 6 reports on the coordination chemistry of L¹, L⁴ and L⁵ with chromium ions. Treatment of CrCl₂ or CrCl₃ with one molar equivalent of [Li(L¹)(Et₂O)₂] (32) yielded heteroleptic Cr(II) complex [Cr(L¹)(μ-Cl)(THF)]₂ (33) and Cr(III) complex [Cr(L¹)Cl₂(THF)₂] (34), respectively. Attempts to reduce 33 and 34 with potassium metal, potassium graphite or magnesium were unsuccessful, yielding [Cr(L¹)₂] (35). Reaction chemistry of 35 was also studied in our research work. No reaction was observed in the reaction of 35 with PhEEPh (E = S, Se). Treatment of 35 with iodine led to the isolation of iodide bridged heteroleptic Cr(II) complex [Cr(L¹)(μ-I)(THF)]₂ (36). Simple monodentate amido ligands L⁴ and L⁵ were also used to prepare Cr(I) complexes. Treatment of anhydrous CrCl₂ with [LiL⁴(Et₂O)₀.₅] and [LiL⁵(Et₂O)₂] (28) afforded oxidative deprotonation products [Cr{N(C₆H₃Prⁱ₂-2,6)(SiMe₂CH₂)}₂Cr(L⁴)] (37) and [Cr(L⁵){N(C₆H₃Prⁱ₂-2,6)(SiBuᵗMeCH₂)}] (38). Attempts to synthesize monovalent chromium complexes supported by the L¹, L⁴ and L⁵ ligands were still in progress during the submission of this thesis. / Chapter 7 summarizes the results of the present studies. A brief description on the future direction of this research work is also presented. / 本項研究工作主要針對兩類負一价含氮配体，即雙齒叠氮基配体[(DippN)N(NDipp)]⁻ (Dipp = Prⁱ₂C₆H₃−2,6) (L¹)和單齒苯胺基配体[N(R)(Ar)]⁻ (R = SiMe₃, Ar = C₆H₃Me₂-2,6 (L²), C₆H₂Me₃-2,4,6 (L³) or C₆H₃Prⁱ₂-2,6 (L⁴); R = SiBuᵗMe₂, Ar = C₆H₃Prⁱ₂-2,6 (L⁵))的配位化學進行研究。本研究工作的第一部分致力於研究二價鑭系叠氮基配合物的合成，結構及其化學反應性。第二部分研究工作主要集中于由苯胺基構築的低價態，低配位數的第一周期后過渡金属的配位化學研究。最後一部分工作闡述了二價鉻叠氮基配合物和苯胺基配合物的合成，結構和表徵。 / 第一章概述了二價鑭系含氮配合物的發展。同時，也簡要闡述低價態，低配位數過鍍金属含氮配合物的研究工作。 / 第二章描述了二價釤叠氮基配合物[Sm(L¹)₂(THF)₂] (2)的製備，結構及其化學反應性。配合物2是由SmI₂(THF)₂與兩當量的鉀叠氮基化合物[KL¹(THF)₀.₅] (1) 反應製得。配合物2的電化學性質採用了循環伏安法進行了研究。介於配合物2為強還原劑，它與一系列無機/有機化合物的反應也予以探索。配合物2與AgCl或PhCH₂Cl反應得到了三價釤雙叠氮基氯化物[Sm(L¹)₂Cl(THF)₂](3)，同時配合物2與單質碘I₂反應得到了碘化物[Sm(L¹)I₂(THF)₃] (4)。配合物2與二苯基硫族化合物PhSSPh及PhSeSePh反應得到了相應的三價釤硫族配合物[Sm(L¹)₂(EPh)(THF)](E = S (5), Se (6))。與之相反，配合物2與位阻較大的二苯基硫族化合物ArEEAr (Ar = Buᵗ₂C₆H₃−2,6, E = S, Se和Te)反應得到了均配的三價釤三叠氮基配合物[Sm(L¹)₃] (7)。此外，配合物2與O₂, S₈, Se, Ph₃P=Se和BuᵗOOBuᵗ反應都生成了配合物7。配合物2與苯肼化合物PhNHNH₂和PhNHNHPh反應得到了相應的三價釤苯肼配合物[Sm(L¹)₂(DMAP)₂(NH₂NPh)] (8) (DMAP = 對二甲基胺吡啶)以及[Sm(L¹)(THF)(μ-η²:η²-PhNNPh)]₂(9)。另外，本章對配合物2與偶氮苯;二苯基酮;9-芴酮;金剛烷叠氮化物;二環已基碳二亞胺;二異丙基碳二亞胺以及二硫化碳的反應性也進行了研究。 / 第三章講述了對該叠氮基配体L¹所衍生出的二價鐿和銪配合物的配位化學研究工作。二價鑭系碘化物LnI₂(THF)₂(Ln = Yb, Eu)與兩當量的鈉叠氮基化合物[Na(L¹)(THF)₃] (10)的複分解反應得到相應的二價鑭系雙叠氮基配合物[Eu(L¹)₂(THF)₂] (11)以及[Yb(L¹)₂(THF)₂] (12)。在製備二價鐿雙叠氮基配合物[Yb(L¹)₂(THF)₂] (12)的過程中同時得到了異配的二價鐿碘橋連單叠氮基配合物[Yb(L¹)(μ-I)(THF)₂]₂.(C₆H₁₄) (13.C₆H₁₄)。配合物12與CuCl的氧化反應得到三價鐿叠氮基氯化物[Yb(L¹)₂Cl(THF)₂] (14)。此外，配合物12與二苯基硫族化合物PhSSPh及PhSeSePh反應得到了相應的三價鐿硫族配合物[Yb(L¹)₂(EPh)(THF)] (E = S (15), Se (16))。然而，配合物12與單質硫和單質硒的反應生成唯一的產物，即均配的三價鐿三叠氮基配合物[Yb(L¹)₃] (17)。 / 第四章闡述了由苯胺基配体L²-L⁵所衍生的低價態，低配位數第一周期后過渡金屬的製備以及結構表徵。通過金屬氯化物MCl₂(M = Fe, Co)和一當量的鋰苯胺基化合物反應得到相應的二價鐡和鈷的單苯胺基配合物[M(L³)Cl(TMEDA)] (M = Fe (20) 和 Co (22))。配合物[Co(L²)Cl(TMEDA)] (21), 22和[Co(L³)Cl(TMEDA)] (23) 與金屬鉀的還原反應分別得到相應的一價鈷苯胺基配合物[CoL²]₂ (24), [CoL³]₂ (25) 和 [CoL⁴]₂ (26)。與此同時，二價鐡單苯胺基配合物[Fe(L⁴)Cl(TMEDA)] (23)與金屬鉀反應得到了一價鐡-偶氮配合物[{FeL⁴(TMEDA)}₂(μ-η¹:η¹-N₂)] (27)。配合物24-27的分子結構及其物理性質分別以X射綫衍射晶体學，波譜學以及循環伏安法表徵。密度泛函(DFT)這一理論計算方法也被用來瞭解這些配合物的電子結構。 / 第五章描述了三個二配位的第一周期后過渡金屬配合物[M(L⁵)₂] (M = Fe (29), Co (30), Ni (31))的製備和表徵。它們由相應的無水金屬鹵化物MCl₂ (M = Fe, Co)或NiBr₂(DME)與[LiL⁵(Et₂O)₂] (28)反應製得。配合物29-31的固體結構由X射綫衍射分析獲得。它們的光學性質和電學性質也分別由波譜方法（紫外可見光光譜，紅外光譜）以及循環伏安法表徵得到。含時密度泛函(TD-DFT)這一計算分析方法也被用來瞭解這些化合物紫外可見光光譜性質。此外，配合物31在有機烯烴與苯硅烷PhSiH3的硅氫化反應中被證實為有效的催化劑。 / 第六章講述了由配体L¹, L⁴與L⁵所構築的二價鉻的配位化學的研究。通過無水二氯化鉻CrCl₂或三氯化鉻CrCl₃與一當量的鋰叠氮基配合物[Li(L¹)(Et₂O)₂] (32)反應分別成功製備了相應的異配的二價鉻配合物[Cr(L¹)(μ-Cl)(THF)]₂ (33) 以及三价鉻配合物[Cr(L¹)Cl₂(THF)₂] (34)。利用金屬鉀，鉀碳以及單質鎂來還原配合物33和34生成了二價鉻雙叠氮基配合物[Cr(L¹)₂] (35)。此外，配合物35的反應性能也在本項工作得以研究。然而，在配合物35與二苯基硫族化合物PhSSPh及PhSeSePh反應中並沒有觀察到明顯的反應變化，依舊得到了原料配合物35。配合物35與單質碘I₂反應得到了異配碘橋連二價鉻配合物[Cr(L¹)(μ-I)(THF)]₂ (36)。單齒苯胺基配体L⁴和L⁵也被嘗試用來合成一價鉻配合物。無水二氯化鉻CrCl2與鋰苯胺基化合物[LiL⁴(Et₂O)₀.₅]和[LiL⁵(Et₂O)₂] (28)反應分別生成了氧化脫質子產物[Cr{N(C₆H₃Prⁱ₂-2,6)(SiMe₂CH₂)}₂Cr(L⁴)] (37) and [Cr(L⁵){N(C₆H₃Prⁱ₂-2,6)(SiBuᵗMeCH₂)}] (38)。關於利用叠氮基配体L¹，以及苯胺基配体L⁴和L⁵來製備一價鉻配合物的相關工作在遞交本論文的過程中还在進行中。 / 第七章總結了本論文的研究成果，並對本項工作未來的發展作出了簡要的描述。 / Yun, Lei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2015. / Includes bibliographical references. / Abstracts also in Chinese.80-30|aDetailed summary in vernacular field only. / Title from PDF title page (viewed on 21, December, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.