Global ETD Search

1	Co-ordination chemistry of the 1,3-dithiole-2-thione (DMIT) and 2-one-4,5-dithiolato (DMIO) compounds Chohan, Zahid H. January 1997 (has links) Various bis-dmio and -dmit zincate complexes, [Q]<SUB>2</SUB>[Zn(dmio)<SUB>2</SUB>] [Q = NEt<SUB>4</SUB>, 1,4-dmp, Ph<SUB>4</SUB>P and FcCH<SUB>2</SUB>NMe<SUB>3</SUB>] and [Q]<SUB>2</SUB>[Zn(dmit)<SUB>2</SUB>] [Q = FcCH<SUB>2</SUB>NMe<SUB>3</SUB>], have been prepared and characterised by IR, <SUP>1</SUP>H and <SUP>13</SUP>C-NMR spectral and elemental analysis data. The solid state structure of [FcCH<SUB>2</SUB>NMe<SUB>3</SUB>]<SUB>2</SUB>[Zn(dmio)<SUB>2</SUB>] was determined by X-ray crystallography. The complexes, [Q]<SUB>2</SUB>[Zn(dmio)<SUB>2</SUB>] and [Q]<SUB>2</SUB>[Zn(dmit)<SUB>2</SUB>], have been further used as precursors of various dmio and dmit complexes of tin (IV) and antimony (III) and (V). Metal exchange reactions with these complexes have also been investigated. The neutral tin compounds, R<SUB>2</SUB>Sn(dmio) [RR' = Me<SUB>2</SUB>, Et<SUB>2</SUB>, Bu<SUB>2</SUB>, Ph<SUB>2</SUB> and MeO<SUB>2</SUB>CH<SUB>2</SUB>CH<SUB>2</SUB>] have been synthesised and characterised by IR, <SUP>1</SUP>H, <SUP>13</SUP>C and <SUP>119</SUP>Sn-NMR spectral and elemental analysis data and for Me<SUB>2</SUB>Sn(dmio) by X-ray diffraction. The compounds, [Q][R<SUB>2</SUB>Sn(dmio)X] [Q = NEt<SUB>4</SUB>, FcCH<SUB>2</SUB>NMe<SUB>3</SUB> ; R = Ph, Et ; X = Cl] and [Q][R<SUB>2</SUB>(dmit)X] [Q = FcCH<SUB>2</SUB>NMe<SUB>3</SUB> ; R = Ph ; X = Cl], have been prepared and halide (X) exchange reactions in [Q][R<SUB>2</SUB>Sn(dmio)X] [Q = NEt<SUB>4</SUB> ; R=Ph ; X=Cl] have been investigated using alkali metal halides and pseudohalides [NaI, NaBr and NaSCN]. The solid state structures of [NEt<SUB>4</SUB>][Ph<SUB>2</SUB>Sn(dmio)Cl], [NEt<SUB>4</SUB>][Ph<SUB>2</SUB>Sn(dmio)-SCN] and [NEt<SUB>4</SUB>][NEt<SUB>4</SUB>][Et<SUB>2</SUB>Sn(dmio)Br] have been determined. The monoestertin bis-dmio complexes, [Q][MeO<SUB>2</SUB>CCH<SUB>2</SUB>CH<SUB>2</SUB>Sn(dmio)<SUB>2</SUB>] [Q = NEt<SUB>4</SUB>, 1,4-dmp and Ph<SUB>4</SUB>P] and the neutral diestertin dmio complex, [(MeO<SUB>2</SUB>CCH<SUB>2</SUB>CH<SUB>2</SUB>)<SUB>2-</SUB>Sn(dmio)], have been synthesised and characterised. The solid state structure of [NEt<SUB>4</SUB>][MeO<SUB>2</SUB>CCH<SUB>2</SUB>CH<SUB>2</SUB>Sn(dmio)<SUB>2</SUB>] has been determined. Also, the tris-dmio and dmit complexes, [Q]<SUB>2</SUB>[Sn(dmit)<SUB>3</SUB>] [Q = NEt<SUB>4</SUB>, 1,4-dmp, Ph<SUB>4</SUB>P and FcCH<SUB>2</SUB>NME<SUB>3</SUB>] and [Q][Sn(dmit)<SUB>3</SUB>] [Q = FcCH<SUB>2</SUB>NMe<SUB>3</SUB>] have been prepared and characterised. The antimony (III) bis-dmio complexes, [Q][Sb<SUP>III</SUP>(dmio)<SUB>2</SUB>] [Q = NEt<SUB>4</SUB>, 1,4-dmp, Ph<SUB>4</SUB>P and FcCH<SUB>2</SUB>NMe<SUB>3</SUB>], and antimony (III) bis-dmit complex, [Q][Sb<SUP>III</SUP>(dmio)<SUB>2</SUB>] [Q = FcCH<SUB>2</SUB>NMe<SUB>3</SUB>], have been synthesised and fully characterised by IR, <SUP>1</SUP>H and <SUP>13</SUP>C-NMR spectral and elemental analysis data. 546 Antimony; Zincate salts
2	Synthèse et développement de la réactivité des triorganozincates de lithium chiraux en addition nucléophile énantiosélective et application à la synthèse de produits bioactifs. / Synthesis and development of the reactivity of chiral lithium triorganozincate to enantioselective nucleophilic addition and application to the synthesis of bioactive compounds Chaumont-Olive, Pauline 30 November 2018 (has links) Le développement de méthodes de synthèse asymétriques a largement été exploré au cours des vingt dernières années et en particulier par le biais de réactifs organométalliques. Bien que ces processus mènent à d’excellents résultats en terme d’énantiodiscrimination, l’objectif de cette thèse a été de développer de nouveaux outils de synthèse peu onéreux, respectueux des fonctions sensibles environantes et permettant l’accès aux composés attendus avec de bons rendements et excès énantiomériques. Dans cet optique, des triorganozincates de lithium chiraux ont été étudiés. Des méthodes d’alkylation et d’arylation 1,2 énantiosélectives d’aldéhydes, comportant comme partenaire chiral la (R)-N-(2-iso-butoxybenzyl)-1- phenyléthanamine, ont ainsi été développées et mises en application sur divers aldéhydes. Les alcools secondaires correspondants ont été obtenus avec de bons rendements (jusqu'à 83%) et d’excellents excès énantiomériques (jusqu'à 99%). Ces procédures ont ensuite été appliquées à la synthèse asymétrique de produits naturels et/ou bioactifs tels que la Spiromastilactone A, la (R)-Néobénodine et la (R)-Orphénadrine. Par ailleurs, la synthèse de nouveaux ligands de type amino-alcool a été développée dans le but ultime de désymétriser des substrats de type imines cycliques. / The development of new asymetric methodologies have been widely explored during the last twenty years and in particular through organometallic reagents. Although these processes lead to excellent results in terms of enantiodiscrimination, the goal of this thesis was to develop new tools: cheap, chemoselective and allowing the access to the desired compounds with high yields and enantiomeric excesses. In this context, chiral lithium triorganozincates have been studied. Enantioselective nucleophilic 1,2 alkylation and arylation of aldehydes reactions, including (R)-N-(2-iso-butoxybenzyl)-1-phenylethanamine as the chiral ligand, have been optimized toward various aldehydes. The expected secondary chiral alcohols have been obtained with good yields (up to 83%) and high enantiomeric excesses (up to 99%).These processes have been then applied to the asymmetric synthesis of naturals and/or bioactive compounds as Spiromastilactone A, (R)-Neobenodine and (R)-Orphenadrine. Finally, the access to new amino-alcohols have been developed with the ultimate goal to engage those species as the chiral partner when reacting chiral lithium zincates with imines. Complexe organo(bi)métallique Zincates de lithium chiraux Synthèse asymétrique Addition 1,2 énantiosélective Ligand chiral Synthèse de composés bioactifs Organo(bi)metallic complex Chiral lithium zincate Asymmetric synthesis Enantioselective 1,2 addition Chiral ligand Bioactive compounds synthesis 547.05
3	Mathematical modelling of primary alkaline batteries Johansen, Jonathan Frederick January 2007 (has links) Three mathematical models, two of primary alkaline battery cathode discharge, and one of primary alkaline battery discharge, are developed, presented, solved and investigated in this thesis. The primary aim of this work is to improve our understanding of the complex, interrelated and nonlinear processes that occur within primary alkaline batteries during discharge. We use perturbation techniques and Laplace transforms to analyse and simplify an existing model of primary alkaline battery cathode under galvanostatic discharge. The process highlights key phenomena, and removes those phenomena that have very little effect on discharge from the model. We find that electrolyte variation within Electrolytic Manganese Dioxide (EMD) particles is negligible, but proton diffusion within EMD crystals is important. The simplification process results in a significant reduction in the number of model equations, and greatly decreases the computational overhead of the numerical simulation software. In addition, the model results based on this simplified framework compare well with available experimental data. The second model of the primary alkaline battery cathode discharge simulates step potential electrochemical spectroscopy discharges, and is used to improve our understanding of the multi-reaction nature of the reduction of EMD. We find that a single-reaction framework is able to simulate multi-reaction behaviour through the use of a nonlinear ion-ion interaction term. The third model simulates the full primary alkaline battery system, and accounts for the precipitation of zinc oxide within the separator (and other regions), and subsequent internal short circuit through this phase. It was found that an internal short circuit is created at the beginning of discharge, and this self-discharge may be exacerbated by discharging the cell intermittently. We find that using a thicker separator paper is a very effective way of minimising self-discharge behaviour. The equations describing the three models are solved numerically in MATLABR, using three pieces of numerical simulation software. They provide a flexible and powerful set of primary alkaline battery discharge prediction tools, that leverage the simplified model framework, allowing them to be easily run on a desktop PC. advection anode asymptotic analysis BET surface area binary electrolyte boundary condition Butler-Volmer equation cathode closed circuit voltage concentration polarisation control volume current path discretisation diffusion electrochemical reaction electrode electrolytic manganese dioxide EMD crystals EMD particles exchange current density geometric surface area initial condition linearisation macrohomogeneous porous electrode theory mathematical model Nernst equation ohmic losses open circuit voltage ordinary differential equation overpotential partial differential equation perturbation techniques potassium hydroxide potassium zincate precipitation reaction primary battery separator paper simulation ternary electrolyte theoretical capacity utilisation zinc zinc oxide

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Co-ordination chemistry of the 1,3-dithiole-2-thione (DMIT) and 2-one-4,5-dithiolato (DMIO) compounds

Mathematical modelling of primary alkaline batteries