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1
Greenhall, Martin Paul. "Fluorinated anions." Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6503/.
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Each of my four main areas of work is concerned with the formation and further reactions of organic fluorinated anions. a) We have investigated the fluoride ion induced reactions of 2H-pentafluoropropene with some perfluoro-aromatic compounds, forming a series of aryl substituted carbon acids and their corresponding carbanions. Also included is a study of an unusual product that was formed with pentafluoronitrobenzene as the aromatic substrate. b) Some fluorinated dienes have been generated from the fluoride ion induced reactions of dimethylacetylenedicarboxylate with a series of cyclic fluorinated alkenes. With perfluorocyclohexene, a variable temperature n.m.r. investigation indicated that one of the products was fluxional at room temperature. Products derived from, perfluorocyclopentene were then further reacted with mono- and bi-functional nucleophiles forming some new products including some interesting polycyclic compounds. c) We have studied the fluoride ion induced reactions of malononitrile and phenylsulphonylacetonitrile with a range of polyfluorinated aromatic and heteroaromatic systems. This study has yielded a series of stable fluorinated organic caesium salts which could be crystallised. Acidification of these salts yielded a series of conjugate acids and some acidity measurements were made. Analysis of n.m.r. data has shed some light on the n.m.r. consequences of tautomerisation which was observed in some of the conjugate acids. A highly unusual carbon-13 n.m.r. concentration effect was studied for several pyrimidyl salts in perdeuteroacetone solution. d) The reaction of bifunctional carbon acids with fluorinated dienes has been used to develop a route to new pentadienyl anions, cyclopentadienes, and cyclopentadienyl anions. FAB mass spectroscopy has proved to be an important tool in the study of our anionic species. Some unusual thermal isomerisation behaviour of the new cyclopentadienes has also been observed and investigated.
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Kawachi, Atsushi. "The Chemistry of Functionalized Silyl Anions." Kyoto University, 1995. http://hdl.handle.net/2433/77813.
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Morris, Daniel S. "Redox chemistry of perrhenate and other anions." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/31480.
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This thesis discusses reduction and oxidation reactions catalysed by the perrhenate anion and oxidation reactions catalysed by other oxo-anions i.e. sulfate and nitrate. Chapter one introduces catalytic hydrosilylation, hydroboration, deoxydehydration and alkene epoxidation and some of their applications, with a focus on high oxidation state complexes. Chapter two describes the synthesis of a salt of perrhenate [N(hexyl)4][ReO4] which is highly soluble in organic solvents. The use of this salt as a catalyst for both the hydrosilylation and hydroboration of carbonyl compounds and carbon dioxide is discussed. Catalytic methylation of amines and anilines with carbon dioxide and hydrosilanes is also reported. Labelled carbon dioxide reactions and DFT calculations are conducted in order to understand the mechanism of carbon dioxide reduction using hydrosilanes. Chapter three outlines the synthesis of a number of alkylammonium and pyridinium perrhenate salts and their application in the deoxydehydration reaction, converting vicinal diols to alkenes. The role of the counterion is discussed with pyridinium perrhenates shown to be more effective catalysts. DFT calculations are conducted to identify the most likely pathway of the catalytic cycle. Alternative reducing agents to the triphenylphosphine initially used are also studied. Chapter four reports results of organic salts of perrhenate, sulfate and nitrate as oxidation catalysts, specifically their ability to catalyse epoxidations of alkenes. By the formation of supramolecular ion pairs (SIPs), these anions are made organic soluble which is found to significantly enhance their catalytic ability, however, the organic counterions used to form these SIPs were found to be of importance. Ionic liquids are also used for the epoxidation of alkenes. Solution studies are presented to further understanding of how these compounds interact with one another in solution. Chapter five contains experimental conditions and characterisation for compounds discussed in this work.
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Buck, J. "Vinyl anions in synthesis." Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353565.
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Downard, Kevin M. "Gas phase chemistry of organic anions involving isomerisation /." Title page, contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phd748.pdf.
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Camiolo, Salvatore. "Anions in supramolecular chemistry : binding, sensing and assembly." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252044.
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Allasia, Sara. "Dipyrromethane based receptors for anions." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/67198/.
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This thesis is principally concerned with the synthesis of a range of dipyrromethane based receptors and their ability to bind anions, in particular carboxylates of amino acid derivatives. Chapter I provides a general introduction to the field of Supramolecular Chemistry and its applications. In this chapter a series of receptors for anions are presented their properties discussed. A particular attention is given to the aromatic heterocycles based receptors and to enantioselective receptors. Chapter II describes the synthesis of a series of acyclic receptors which are the results of subsequent modifications of a simple tweezer, based on a dipyrromethane unit coupled with two butyl amines, previously studied by the group.1 The binding properties with a series of anions are presented and, for the chiral receptors, the binding properties with Nprotected amino acids were investigated. Chapter III describes the synthesis and the binding properties of a series of macrocycles obtained by modifications of the tweezer receptors. The binding properties of the macrocyclic receptors with a series of anions and amino acids are also presented.
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Hiscock, Jennifer R. "Binding anions using simple neutral molecules." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/171157/.
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This thesis reports a number of novel neutral, hydrogen bond donating anion receptors and describes their anion coordination properties in both the solution and solid states. A set of ten urea/thiourea linked indole/carbazole groups were found to have high affinities for a variety of oxo-anions in highly competitive DMSO solutions. Of these receptors, the diindolylurea motif was found to be excellent for the binding of dihydrogen phosphate. This group of receptors were found to form 1:1 complexes in solution with various anions but more complex 2:1 and 3:1 receptor:anion complexes were observed in the solid state. Deprotonation of the bound protonated oxo-anion was observed with these 2:1 and 3:1 complexes. The basic diindolylurea motif was then extended by the incorporation of further NH bond donor groups from amide, indole and carbazole functionalities. This group of receptors were found to form 1:1 complexes in both the solution and solid states, with the binding mode dependent of the geometry of the anion. These compounds also showed spontaneous crystallisation with sulfate in as little as 20 minutes. These receptors showed high affinities for the oxo-anions and gave the first examples of solution state deprotonation of bound protonated oxo-anions. A set of three dimensional indole-based receptors was also synthesised, utilising the TREN and pin-wheel scaffolds. These receptors contain between six and fifteen NH bond donor groups that give a range of anion binding modes, some too complex to be defined, that generally show a preference for the oxo-anions. Again, an example of deprotonation of the bound protonated oxo-anion was observed.
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Ogle, Mark Edward. "Spectroscopic studies of [alpha],[omega]-diphenylpolyenyl anions." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/30363.
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Timmons, Christopher L. "Fluorocarbon Post-Etch Residue Removal Using Radical Anion Chemistry." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/10583.
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During fabrication of integrated circuits, fluorocarbon plasma etching is used to pattern dielectric layers. As a byproduct of the process, a fluorocarbon residue is deposited on exposed surfaces and must be removed for subsequent processing. Conventional fluorocarbon cleaning processes typically include at least one plasma or liquid treatment that is oxidative in nature. Oxidative chemistries, however, cause material degradation to next generation low-dielectric constant (low-k) materials that are currently being implemented into fabrication processes. This work addresses the need for alternative fluorocarbon-residue removal chemistries that are compatible with next generation low-k materials. Radical anion chemistries are known for their ability to defluorinate fluorocarbon materials by a reductive mechanism. Naphthalene radical anion solutions, generated using sodium metal, are used to establish cleaning effectiveness with planar model residue films. The penetration rate of the defluorination reaction into model fluorocarbon film residues is measured and modeled. Because sodium is incompatible with integrated circuit processing, naphthalene radical anions are alternatively generated using electrochemical techniques. Using electrochemically-generated radical anions, residue removal from industrially patterned etch structures is used to evaluate the process cleaning efficiency. Optimization of the radical anion concentration and exposure time is important for effective residue removal. The efficiency of removal also depends on the feature spacing and the electrochemical solvent chosen. The synergistic combination of radical anion defluorination and wetting or swelling of the residue by the solvent is necessary for complete removal. In order to understand the interaction between the solvent and the residue, the surface and interfacial energy are determined using an Owens/Wendt analysis. These studies reveal chemical similarities between specific solvents and the model residue films. This approach can also be used to predict residue or film swelling by interaction with chemically similar solvents.
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Berryman, Orion Boyd 1981. "Anions and electron-deficient aromatic rings." Thesis, University of Oregon, 2008. http://hdl.handle.net/1794/8159.
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xx, 281 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.More than two-thirds of all enzyme substrates and cofactors are anionic, emphasizing the essential role that anions play in biological processes. Moreover, anions can have detrimental effects on the environment by causing ground water contamination when anions such as perchlorate, phosphate and nitrate develop in intolerable levels. Owing to the prevalent nature of anions, traditional strategies employed to target anions--including hydrogen bonding, metal ion coordination and electrostatic interactions--have been extensively studied. An alternative approach to anion binding would complement the powerful array of existing techniques. Recently, in the supramolecular chemistry community, new insight has been cast on how anions attractively interact with electron-deficient arenes, suggesting that aromatic rings are a viable anion binding strategy to balance existing methods. Chapter I provides a historical perspective of anions interacting with electron- deficient arenes. This outlook has its origins in the late 1800s with the discovery of colored charge-transfer complexes between donor and acceptor molecules and continues with the progression of the field leading up to the recent supramolecular fascination. Chapter II represents our initial efforts at measuring anion/arene interactions in solution. In particular, sulfonamide based hydrogen bonding receptors were developed with pendant aromatic rings to test the strength of anion/arene interactions in solution. Complementary computational chemistry and crystallography were utilized to supplement the solution studies. Chapter III describes our quantum calculations and crystallographic efforts at using only electron-deficient arenes to bind halides. A Cambridge Structure Database survey supports our emphasis of understanding multiple anion/arene interactions. Chapter IV illustrates how tripodal anion receptors can be developed to bind anions using only electron-deficient aromatic rings. Furthermore, subtle changes in anion binding geometries are observed with isomeric receptors and corroborated with Density Functional Theory calculations. Chapter V is dedicated to the preparation of electron-deficient anion receptors that are conformationally stabilized by hydrogen bonds. Chapter VI is committed to using our knowledge of anion binding to study a series of ethynyl-pyridine sulfonamides capable of hydrogen bonding to small molecules and anions. In conclusion, Chapter VII is a summary and future prospective for the field of anion/arene interactions. This dissertation includes previously published and co-authored material.
Adviser: Darren W. Johnson
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Davis, Julian Murray. "Sapphyrins aggregation and anion binding behavior in polar, protic media /." Access restricted to users with UT Austin EID UMI Company copy, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3036590.
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Niedenzu, Philipp M. "Studies on polyboron hydride anions and ammine-borane." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299005304.
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Walrond, Lisa. "Stability and chemistry of boron containing cations, anions, and neutrals." Thesis, University of Ottawa (Canada), 2007. http://hdl.handle.net/10393/27493.
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The structure, thermochemistry, isomerization and dissociation of the CH2BH2 and CH3BH radicals, cations and anions have been explored with a wide range of ab initio levels of computational theory and their formation has been probed by tandem mass spectrometry and RRKM kinetic theory. Calculations predict that CH2B H2&ceilr0;+ is not an equilibrium structure on the potential energy surface. The CH3B H&ceilr0;+ was characterized by its collision-induced dissociation mass spectrum and neutralization-reionization (NR) mass spectrometry was used to generate the CH3B H&ceilr0;• radical. While both CH2B H2&ceilr0;• and CH3B H&ceilr0;• are stable with respect to isomerization and dissociation, a relatively low barrier to the 1,2-hydrogen shift means that pure CH3B H&ceilr0;• can only be made cold, and so the above NR experiment likely produces a mixture of neutrals, of which only CH3B H&ceilr0;• can be reionized. Vertical electron attachment to CH3B H&ceilr0;• is endothermic which means the CH3B H&ceilr0;- anion is unlikely to be made from the cation or radical. In addition, the anion lies in a shallow well of only 48 kJ mol-1 and will undergo fast isomerization to CH2B H2&ceilr0;- below the dissociation limit.
The B(N(CH3)2)3 radical cation and dication structures and dissociation products have been investigated by high level ab initio calculations and experimentally characterized by tandem mass spectrometry. The KER was measured for the metastable dissociation products of the B(N(CH 3)2)3 dication. There were four observed dissociation channels, two involving neutral losses and two involving charge separations. The neutral loss channels successfully compete with the charge separations, the dominant process actually being neutral loss of H2. The KER for the four metastable dissociations were determined to be T0.5(141++) = 368 +/- 18 meV, T0.5(127++) = 144 +/- 12 meV, Th (99+) = 2365 +/- 156 meV, Th(44+) = 2046 +/- 279 meV, and Th(128+) = 1942 +/- 332 meV.
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Pace, Stuart. "Guanidines and their anions : versatile ligands for metallo-organic chemistry." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/15566.
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There are a large number of highly stable systems which are isostructural and isoelectronic to carboxylates. One of these, amidinates, the 1,3-nitrogen analogues of carboxylates, show a rich and varied coordination to both main group and transition metals. However, the triaza analogues, substituted guanidinates, had received little or no attention as ligands prior to this work, in which the ligand chemistry of neutral, mono- and dianionic guanidines has been explored. The synthesis and characterisation of tri-substituted guanidines containing a variety of alkyl (iPr, lBu, Cyx) and aryl (Ph, p-tol) substituents is described herein. Preparation of the homochiral substituted N,N',N"-tris((s)-(-)-amethylbenzyl)guanidine and the X-ray crystal structure of its HPF6 salt are also presented. In the solid state the central CN3 unit exhibits local C3 symmetry and has steric elements on one of the plane resulting in two stereochemically different faces. The formation of tetra-substituted N,N-diethyl-N',N"-diphenylguanidine is also detailed. Formation of complexes containing neutral guanidine ligands was achieved in the reactions of N,N',N"-triphenylguanidine with CoCl2 and Ag(SO3CF3). The complexes formed, [Co{PhN=C(NHPh)2]2Cl2] and [Ag{PhN=C(NHPh)2}2][SO3CF3] respectively, were characterised by X-ray crystallography and found to contain monodentate guanidine ligands bound through their imine nitrogen alone. The cobalt complex adopts pseudo-tetrahedral geometry while [Ag{PhN=C(NHPh)2}2] is perfectly linear at silver with the triflate acting only as a counterion. Cleavage reactions of the ruthenium chloro-bridged dimers [(p-cymene)RuCl2]2 and [Cp*RuCl2]2 with various tri-substituted guanidines were undertaken. Two product obtained from these reactions, namely [(p-cymene)Ru{h2-(iPrN)2CNHiPr}Cl] and [Cp*Ru{(h6-p-tol)N=C(NHp-tol)2}]+, were characterised by X-ray crystallography. The first of these contains a ruthenium centre with a h6-arene, terminal chloride and monodeprotonated chelating guanidinate ligand. Meanwhile the second is a sandwich compound in which the guanidine is bound through an arene substituent and not one of its nitrogens.
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Wang, Zhiming 1958. "Anion Exchange and Competition in Layered Double Hydroxides." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc332481/.
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Exchange reactions of anions, especially ferrocyanide and carbonate, with layered double hydroxides (LDHs) were investigated in relation to the origin of life on the early Earth. The effect on ferrocyanide exchange of concentration, pH, reaction time and cations are discussed. It was found that there were two different kinds of ferrocyanide species: one was that intercalated into the layered structure, occupying a site of D symmetry within the LDHs, while in the other, the ferrocyanide group retains full O symmetry. In addition, very low concentration, ferrocyanide associated with LDH will change its FTIR absorption shape. Carbonate was much more strongly intercalated than ferrocyanide into the LDHs, probably because of the strong hydrogen bonding.
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Haynes, Cally J. E. "The design of synthetic transmembrane carriers for anions." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/206159/.
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This thesis reports a number of novel receptors found to facilitate the transmembrane transport of anions in synthetic vesicle systems. A series of structurally simple thioureas were found to function as efficient Cl-/NO3- and Cl-/HCO3- antiporters while the corresponding ureas were inactive. Of these receptors, a simple indolylthiourea was found to be an extremely potent transporter which could function at concentrations as low as 1:25 000 (molar ratio with respect to lipid). Subsequently, a series of bipodal bis-alkyl-indolylureas were found to mediate Cl-/NO3 - antiport, with the observed anion transport found to be highly dependent on the length of the central alkyl chain bridging the two indolylurea moieties. The mechanism of transport and the structure-activity relationships were extensively investigated using a wide range of vesicle-based techniques. The solution phase anion binding properties of these receptors was found to be complex as a result of the flexibility of the receptors and the distance between the binding sites. The binding of dihydrogen phosphate and oxalate by receptors in this series was also demonstrated in the solid state. A series of bipodal bis-phenylthioureas were also found to mediate Cl-/NO3 - and Cl-/HCO3- antiport which was again found to be dependent on the alkyl chain length. The effect of substituent variation on transport activity was also examined, while the solution phase binding properties were found to be similarly complex to the bis-indolylurea receptors. The anion transport activity of a series of strapped calix[4]pyrroles provided by J. L. Sessler and C.-H. Lee was investigated. It was found that the straps were able to encourage transport mechanisms not exhibited by the parent macrocycle, while a series of control compounds were inactive
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Saad, Fawaz Ahmed. "Co-ordination chemistry of novel tripodal ligands designed to host anions." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/55112/.
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The development of novel ligands for the complexation of transition metal ions in inorganic chemistry is a rapidly developing field of study. The broad objective of this work is to design novel tripodal transition metal based receptors of (TPA) frame work which can act as hosts for small molecules (guests) e.g. fluoride and succinate. In addition, investigation into the co-ordination chemistry of those receptors with first row transition metals were explored using variety of characterizing techniques such as: Infrared Spectroscopy (IR), Electronic transitions (UV-Vis), Mass Spectrometry (MS), Nuclear Magnetic Resonance (NMR), Cyclic voltammetry (CV) and Single Crystal Diffractometer (X-Ray). Mono, Bis and Tris thiourea tripodal ligands have been synthesised and their co ordination chemistry has been investigated (chapter 2, 3 and 4) as well as the binding studies of the bisthiourea (chapter 3) to bind: fluoride and succinate using *H NMR titration technique. The co-ordination chemistry of TPPA with some first row transition metals has been studied and it was expected to show high affinity for seven coordination sphere and indeed it has shown strong preference for mono capped octahedral geometry (chapter 5).
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Turbervill, Robert S. P. "Solution reactivity studies of group 15 Zintl anions towards unsaturated substrates." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:c79adeb3-bf62-4c38-8635-de8bd9fb4ca4.
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This thesis describes selected reactivity studies of group 15 Zintl anion [E7]3– (E = P, As) derived cages towards a series of unsaturated organic molecules. The synthesis and characterization of forty-two compounds derived from [E7]3– cages are detailed herein. A high yielding procedure for the synthesis of [HE7]2– (E = P, As) from the K3E7 Zintl phase has been developed. This solves prior issues with poor solubility and variable purity of the Zintl phases. The conditions required for the deprotonation of the phosphorus congener to [P7]3– are described. The reactivity of both [P7]3– and [HP7]2– towards carbon dioxide and isolobal isocyanates and carbodiimides was explored. This yielded a series of monofunctionalized [E7R]2– cages, via a net hydropnictination of a C=N double bond of the organic substrate. The protonation chemistry of these anions was further investigated, resulting in the formation of the protic [HP7C(NHDipp)(NDipp)]– cluster. This anion is capable of further hydrophosphination chemistry to give a series of difunctionalized heptaphosphide cages. The reaction of [E7]3– with alkynes results in the formation of the relatively unusual 1,2,3-tripnictolide anions. A series of such anions have been prepared, encompassing all of the previously reported anions and several novel species. Investigation of the coordination properties of these cyclopentadienyl analogues shows that they are superior π acceptor ligands. A synthetic route to [P5]– as a compositionally pure solid, and some initial studies on its protonation chemistry are also additionally presented.
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Hailemichael, Goitom Aron. "Indirect capillary electrophoretic detection methods of cations and anions." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/49989.
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Thesis (MSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: Capillary electrophoresis (CE) has recently attracted considerable attention as a promising analytical technique for the separation of cations and anions in complex matrices. Determination of ions in aqueous samples using capillary electrophoresis can be accomplished with indirect UV detection. Most inorganic ions have weak absorption profiles in the UV-Vis wavelength range. These mostly non-absorbing species are commonly detected by indirect UV absorbance through addition of an absorbing co-ion (chromophore) into the electrolyte. Inorganic cations most often require an additional complexing agent to selectively alter their similar mobilities and proper separation. For optimal determination of alkali, alkaline, and transition metal ions, several electrolytes systems were studied. These include pyridine, imidazole and 4- aminopyridine as UV-absorbing species and glycolic acid, a-hydroxyisobutyric acid and their mixture were used as complexing reagents. A mixture of 10 metal ions (K+, Na+,Ca2+, Mg2+, Mn2+, Fe2+, Cd2+, Pb2+, Ni2+and Zn2+) was successfully separated. Detectionwas performed at 210,214 and 254 nm. In the anion determination chromate and 2, 6 pyridine dicarboxylic acids (PDC) were used as back ground electrolytes for inorganic ions (F-, CI- en SO₄² ̄ ) and organic acids (tartaric acid, malic acid, succinic acid and citric acid) separations respectively. Electroosmotic flow (EOF) was reversed in the direction of the anode by adding Cetyltrimethylammonium bromide (CTAB) to the electrolyte. Highly alkaline conditions were used to confer a negative charge on inorganic and organic anions to promote their migration towards the anode. The detection wavelength was 200 nm. All peaks were completely resolved and well separated. The limit of detection (LOD) of cations and anions were in the range of 0.5 - 3 ppm and 2 - 3.5 ppm respectively. The described methods were used successfully in routine analysis of real samples. This includes the qualitative and quantitative analysis of an environmental water samples from the areas surrounding Stellenbosch, beverages and orange juice.
AFRIKAANSE OPSOMMING: Kapillêre Elektroforese (CE) het in die onlangse verlede heelwat aandag getrek as "n belowende analitiese tegniek vir die skeiding van katione en anione in komplekse monsters. Die bepaling van ione in waterige medium met kapillêre elektroforese word gedoen deur indirekte Ultraviolet (UV) deteksie aangesien meeste anorganiese ione swak absorbsie in die die sigbare UV (UV-Vis) golflengtegebied toon. Deteksie van hierdie meestal nie-absorberende spesies word algemeen gedoen deur indirekte UV absorbansie deur die byvoeging van "n ko-ioon (chromofoor) tot die elektroliet. Anorganiese katione benodig dikwels "n addisionele komplekserings reagens om selektief hulle eenderse mobiliteite te verander en sodoende goeie skeiding te bewerkstellig. Vir die optimale bepaling van alkali-, alkali-aard- en oorgansmetaal ione is verskeie elektrolietsisteme bestudeer. Hierdie sluit in piridien, imidasool en 4-aminopiridien as UV absorberende spesies en glikoliensuur, a-hydroksie-isobottersuur asook "n mengsel van die twee as komplekserings reagense. "n Mengsel van 10 metaalione (K+, Na+, Ca2+, Mg2+, Mn2+, Fe2+, Cd2+, Pb2+, Ni2+ en Zn2+) is sukselvol op hierdie wyse geskei. Deteksie is gedoen by golflengtes van 210, 214 en 254 nm. Vir die anioon bepaling is chromaat en 2,6-piridiendikarboksielsuur gebruik as agtergrond elektroliete vir die skeiding van anorganiese anione (F-, CI- en SO₄² ̄ ) en organiese sure (tartaarsuur, malonsuur, suksiensuur en sitroensuur), onderskeidelik. Elektroosmotiese vloei (EOF) is omgekeer na die rigting van die anode deur byvoeging van setieltrimetielammoniumbromied (CTAB) by die elektroliet. Sterk alkaliese kondisies is gebruik om 'n negatiewe lading op die anorganiese en organiese anione te konsentreer en sodoende hul migrasie na die anode te bevorder. Die deteksiegolftengte hier gebruik was 200 nm. Volkome resolusie en goeie skeiding is gerealiseer vir al die pieke. Die deteksielimiete (LOD) vir die katione en die anione was 0.5 - 3 ppm en 2 - 3.5 ppm, onderskeidelik. Die metodes wat beskryf word is suksesvol aangewend vir roetiene analise van werklike monsters. Dit sluit in kwalitatiewe sowel as kwantitatiewe analise van omgewingswater monsters uit die Stellenbosch area, koeldranke en lemoensap.
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Wermer, Joseph Raymond. "Preparation and reactions of anions derived from pentaborane(9) : preparation of new metallaboranes /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu148732358362289.
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Meina, Dominic G. "Chemical and electrochemical studies of borane anions and metallaboranes." Thesis, University of Strathclyde, 1985. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21456.
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Several new monosubstituted anionic derivatives of [B₃H₈]⁻ of the type [B₃H₇(X)]⁻(X = NCSe, NCBPh₃, NCBH₂NCBH₃, NCB₃H₇,NCBH₂CN and NCBH₂CNB₃H₇) have been prepared. The disubstituted anions [B₃H₆(Cl)(X)]⁻(X = NCBH₂NCBH₃, NCBH₂CN and NCB₃H₇) and [B₃H₆(Br) NCB₃H₆(Br)]/⁻ have also been prepared and studied by various spectroscopic techniques. Two-dimensional n. m. r. spectroscopy was shown to be useful in the qualitative determination of the bonding employed in these anions. The electrochemical properties of these anions have been investigated by various techniques. It was found that when the substituent was varied the oxidative stability of the anions varied. Metallaboranes of some of these anions have been prepared by anodic dissolution of a suitable metal in a solution of the anion. The structures and dynamics of substituted derivatives of the [B₉H₁₄]⁻ ion have been studied. The anions [B₉H₁₃(X)⁻(X = CINCSe, NCBPh₃, NCBH₂NCBH₃, NCBH₂CN, NCBH₂CNB₉H₁₃, CN, and NCAgCNB₉H₁₃) and [B₉H₁₂(CN₂]⁻ have been prepared. ¹¹B and ¹H n. m. r. spectroscopy indicated that when the substituent contained electron withdrawing groups (e. g. the hydrogen atoms on NCBH₂NCBH₃) the anion was static at room temperature on the n. m. r. time scale. If no electron withdrawing groups were present on the substituent then the molecule was fluxional at room temperature on the n. m. r. time scale. The electrochemistry of these anions was also studied and it was found that, in some cases, oxidation resulted in cage closure to give substituted nido-derivatives. Anodic dissolution of Cu or Ag in solutions of some of the anions produced metallaboranes. The chemistry and electrochemistry of [B₉H₁₂]⁻ was also studied and the crystal structure of the (N(PPh₃)₂]⁺ salt was obtained. Several new substituted metallaboranes have been prepared by reaction of the substituted octahydrotriborate (1-) or substituted tetradecahydrononaborate (1-) anions with Cu(PPh₃)₂(BH₄). The reactions of Mn(CO)₅ Br with [B₉H₁₃(X)]⁻(X = NCSe, NCBH₂NCBH₃ and NCBPh₃) have also been investigated.
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Mullaney, Benjamin R. "Halogen bonding interlocked host systems for recognition and sensing of anions." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:e3d75598-d025-4c69-aad3-9740c428a9b5.
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This thesis describes the synthesis of halogen bonding receptors for integration within interlocked anion host systems. Chapter 1 introduces the field of supramolecular chemistry, with a particular focus on anion recognition and sensing, halogen bonding, and the synthesis of mechanically interlocked structures. Chapter 2 describes the preparation and anion binding properties of carbazole-based receptor molecules. A systematic anion binding study on a series of halogen- and hydrogen-bonding 3,6-bis-triazolium carbazole acyclic receptors is described initially, followed by the development of a halogen bonding rotaxane. The anion and metal complexation properties of acyclic and macrocyclic systems incorporating the 1,8-bis-triazole carbazole motif are also presented. Chapter 3 details the synthesis and anion complexation investigations of halogen and hydrogen bonding naphthalene-based acyclic and interlocked rotaxane host molecules. Chapter 4 presents receptors based on the 4,4'-bis-triazole-2,2'-bipyridyl motif. A halogen bonding rhenium(I) bipyridyl complex is exploited in the development of a rotaxane host system which optically senses anions via luminescence purely through halogen bonding interactions. The anion recognition and sensing properties of diquat-based receptors are also investigated, and shown to exhibit optical and electrochemical responses to anions. Chapter 5 summarises the major conclusions from Chapters 2-4. Chapter 6 describes the experimental procedures used in the work, and includes characterisation data for the synthesised compounds. Supplementary information relating to crystallographic data, and absorption, luminescence and electrochemical studies, is provided in the Appendices.
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Kravetz, Tina Marie. "Stereoselective course of reactions involving isodicyclopentadienes and their anions /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487260531957018.
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Pearson, C. H. G. "New ion exchange resins for ion chromatography applied to anions." Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372771.
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Karagiannidis, Louise E. "Neutral receptors for the transport of anions across lipid membranes." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/374679/.
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This report describes a novel method, using 33S NMR techniques, for the detection of sulfate transport across synthetic lipid membranes comprised of 1-palmitoyl-2 oleoylphosphatidylcholine. With this method it was possible to verify that tris(2 aminoethyl)amine based (thio)ureas and cyclic peptide based cryptands can promote the transmembrane transport of sulfate anions. This is a particularly notable accomplishment due to the highly hydrophilic nature of the sulfate anion, and the associated challenges with partitioning such a species into a hydrophobic lipid membrane. Furthermore, a series of bis(thio)urea compounds, based on the 1,2- bisaminocyclohexane scaffold are reported as ion transporters, capable of facilitating both chloride/nitrate and chloride/bicarbonate antiport transport processes. They have also been investigated for binding properties with a variety of anions, using 1H NMR techniques. The influence of stereochemistry on the anion binding and transport ability of the receptors is discussed in detail, with cis-stereoisomers being superior anion transporters to the transanalogues. Receptors based on the ortho-phenylenediamine bis-urea motif have been demonstrated as highly effective anion transporters and function by an antiport mechanism of anion transport. Modification of existing transporters, by adding fluorination at the central phenyl ring or by increasing fluorination at the peripheral phenyl groups, yielded highly potent anion transporters capable of surpassing the activity of the natural anion transporter prodigiosin, for chloride/bicarbonate exchange.
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Elkadi, Yasser A. "Dipole-bound anions of molecules and clusters: An ab initio study." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284069.
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The quantum mechanical investigation of molecular dimers, trimers and, to a greater extent, higher clusters, constitutes a legitimate attempt towards linking the gas and condensed phases of matter. The interaction of gas-phase clusters with ionizing media can result in anion formation, a special class of which, the dipole-bound anions is the main focus of this dissertation. By applying special techniques of ab initio calculations to model systems, we have addressed the question of the extent to which certain molecular species can form dipole-bound anions. We have shown the effects of attaching a dipole-bound electron on charge distribution, geometrical distortions, and mechanistic fates of certain reactive clusters. Our investigations include cases of homodimer anions where we reported the feasibility of formation of a dipole-bound anion for the dimer agglomerates to the exclusion of the single molecules (ethylene glycol and hydrogen fluoride). The hydrogen cyanide-water anion is a heterodimer system where our results demonstrate the effect of linkage isomerism on an isomer's ability to form dipole-bound states. Only the [H₂O...HCN]⁻ anion was experimentally detected and it corresponds to the higher EA we reported. In addition, the formation of meta-stable trimer and tetramer dipole-bound anions in the water cluster system is supported by our calculation. The water cluster study demonstrates the utility of ab initio calculation techniques for investigations of reaction mechanisms in the gas phase. For instance, both the mass spectrum intensity pattern and general mechanism of formation of the cluster anions can be inferred from the relative stabilities and geometries that we obtained for the anion and neutral systems. Finally, we point out the potential utility of an IR analysis in distinguishing neutral from anion systems, based on shifts of certain IR bands generated in our harmonic frequency analysis. We hope that our results for electron affinities, dipole moments, and vertical detachment energies will serve as a useful resource for the researchers in the field. In conjunction with the corresponding values measured by experimentalists, both results should provide a self-consistent system for identifying and overcoming shortcomings of both experimental and theoretical approaches of solving chemical and physical problems involving anion formation.
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Venz, Paul Andrew. "Anion chemistry in the sol-gel processing of titania." Thesis, Queensland University of Technology, 1999.
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Arbogast, James K. "Chromatographic behavior of anions and the first row transition metal ions /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487335992905515.
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Holman, K. Travis. "The host-guest chemistry of new members in the cyclotriveratrylene family of cavitands /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924887.
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Edge, Graham J. "Studies into the photochemistry of steroidal nitronate anions and N-alkyloxaziridines." Thesis, Loughborough University, 1985. https://dspace.lboro.ac.uk/2134/11237.
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The photochemistry of nitro-compounds is well documented in the literature. However the photochemical behaviour of nitronate anions has not been widely reported. We have studied the photochemical behaviour of a number of steroidal nitronate anions and found that the major products are hydroxamic acid. ketone and alkene. It was found that the yield of products is influenced by the position of the nitro-group. The hydroxamic acids were found to be the major products in the photolysis of 17-nitronate anions. However, it was observed that in these systems the yield of hydroxamic acid was influenced by the CID ring geometry. In the photolysis of nitronate anions derived from 3.6 and 20-nitro steriods only tentative evidence for hydroxamic acid formation was found in the photolysis of the 6-nitronate anion. The formation of hydroxamic acids from the 17-nitronate anions was observed to be both regio - and stereo-specific and it was postulated that these reactions proceeded via a N-hydroxyoxaziridine anion intermediate. In order to further investigate the possible intermediary of an oxaziridine the synthesis of steroidal N-alkyl oxaziridines was carried out. and their photochemical behaviour examined. It was found that the N-alkyl-17-spiro-oxaziridine rearranged efficientlytoa lactam whereastt-eN-alkyl-20-oxaziridine only gave a poor yield of amide. These results were consistent with those obtained for the nitronate anions. However the lactam formed was of different regio-chemistry to that observed in the photochemical formation of hydroxamic acid. However the observed photochemical rearrangement of the steriodal oxaziridines was fully in accord with theoretical predictions.
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Shade, Matthew. "Redox-active calixarenes as receptors for anions and neutral molecules." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242875.
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Weightman, John S. "Spectroscopic and electrochemical sensing of anions and cations using novel receptor molecules." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/13771.
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The aim of the project was to extend the field of molecular recognition of anions and cations of biochemical, medical, chemical and environmental importance. This was achieved by the use of a number of novel receptor molecules that are designed to bind anionic and cationic guests. The binding of the guest anions and cations was probed by various electrochemical, spectrochemical and IH NMR spectroscopy techniques. The receptor molecules studied included (i) ruthenium(II) trisbipyridyl complexes of acyclic, calix[4]arene and cyclic 2,2'-bipyridine ligands, (ii) the macrocycle Nphenylaza- 15-crown-5, and (iii) crown ether derivatives of diquat. These receptor molecules have been shown to sense anions and cations, such as chloride, bromide, dihydrogen phosphate, sodium, lithium and magnesium. Interestingly, one of diquat crown ether derivatives has been shown to complex both anions and cations at the same time. This is an important development, as the simultaneous molecular trapping of anions and cations in such systems is seen as a possible alternative to the use of ion exchange resins. With a view to producing spectrochemical and/or electrochemical sensor systems, work has been completed by the immobilisation of the novel receptor molecules. This has been achieved by the electropolymerisation of vinyl-substituted ruthenium(Il) trisbipyridyl complexes or the immobilisation of receptor molecules in a polyvinylchloride (PVC) matrix. The latter technique has been particularly successful and has led to the construction of a battery-powered fluorescence detector which has been used for anion sensing.
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Opoku-Agyeman, Bernice. "Complexities in Nonadiabatic Dynamics of Small Molecular Anions." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503094708588515.
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Khuseynov, Dmitry. "Photoelectron Imaging and Photofragmentation of Molecular and Cluster Anions." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/317044.
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The electronic structure and photofragmentation dynamics of several molecular and cluster anions have been investigated in the gas phase via negative ion velocity-map imaging photoelectron spectrometer combined with tandem time-of-flight (TOF) mass spectrometry. Among others, photoelectron imaging investigation of the halogen- and cyano- substituted methyl radicals and corresponding carbenes has been performed on several mono- and hetero- substituted species – dicyanomethyl and chlorocyanomethyl radicals, ·CH(CN)₂ and ·CHClCN, and corresponding carbenes, NCCCN and CClCN. The results are discussed in comparison with the corresponding dichloro- species, focusing on the divergent effects of the halogen and pseudohalogen (CN) substitutions. A cooperative (captodative) interaction of π-donor Cl and π-acceptor cyano groups favors the increased stability of the CHClCN radical, but a competition of the two substituents is observed in the singlet-triplet splitting of the carbene. The experimental results are consistent with high level ab-initio calculations using the spin-flip approach in combination with the coupled-cluster theory. The C-H bond dissociation energies were determined for several substituted methanes and discussed. Additionally, a practical model is presented for describing the energy dependence of laboratory-frame photoelectron angular distributions in direct photodetachment from (in principle) any molecular orbital using linearly polarized light. A transparent mathematical approach is used to generalize the Cooper-Zare central-potential model to initial states of any mixed character. In the limits of atomic photodetachment or photoionization, the model reproduces the Cooper-Zare formula. In the case of electron emission from an orbital described as a superposition of s- and p-type functions, the model yields the previously obtained s-p mixing formula. The formalism is further advanced using the Hanstorp approximation, valid for anion photodetachment only, whereas the relative scaling of the partial wave cross-sections is assumed to follow the Wigner threshold law. The resulting model can be used to describe the energy dependence of photoelectron anisotropy for any atomic, molecular, or cluster anions. As a benchmark case, we compare the predictions of the p-d variant of the model to the experimental results for NO⁻ photodetachment and show that the observed anisotropy trend is described well using physically meaningful values of the model parameters.
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Yan, Jingbo. "Attempted synthesis of new intrinsically electroactive polymers by the condensation of cyclopentadienyl anions with diesters." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1990. http://digitalcommons.auctr.edu/dissertations/676.
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Treatment of diethyl oxalate with two equivalents of sodium cyclopentadienide in THF gave, upon work-up, biscyclopentadienyldiketone-THF contaminated with a small amount of cyclopentadienylethoxyldiketone in 87% yield. Treatment of diethyl oxalate with four equivalents of sodium cyclopentadienide in THF led to, upon work-up, clean biscyclopentadienyldiketone-THF in 91% yield. Treatment of diethyl oxalate with one equivalent of sodium cyclopentadienide in THF gave, upon work-up, oligomers of poly(1,3-diketocyclopentadienyl)-THF in 92% yield. Treatment of diethyl oxalate with one equivalent of Lithium cyclopentadienide in THF gave, upon work-up, oligomers of poly( 1 ,3-dicyclopentadienyl)-THF in 66% yield. Treatment of biscyclopentadienyl diketone with diethyl oxalate in H2O or THF gave, upon work-up, oligomers of poly( 1 ,3-diketocyclopentadienyl). Treatment of diethyl oxalate with sodium cyclopentadienide in the presence of triethylamine in THF gave, upon work-up, oligomers of poly(1,3-dicyclopentadienyl).THF. Treatment of cyclopentadienyl anion with diethyl carbonate in THF gave, upon work-up, oligomers of poly(ketocyclopentadienyl) in 85% yield. Treatment of diethyl carbonate with sodium cyclopentadienide in the presence of triethylamine in THF gave, upon work-up, oligomers of poly(ketocyclopentadienyl)-THF in 83% yield. Treatment of biscyclopentadienyldiketone with iron (II) chloride in H20 or THF gave, upon work-up, brown solids that are paramagnetic. Treatment of poly(1,3-dicyclopentadienyl) with iron (II) chloride in H20 gave, upon work-up, a black solid that are paramagnetic. The new materials prepared were found to be insulators at room temperature when dry and solvent free. Composites prepared from the new materials in this study with PEO and TCNQ are insulators at room temperature and exhibit conductivities at temperature above 60 °C in the range of 10-5 to 10-7 S cm-1.
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Grieve, Alan. "Synthesis of novel bipyridine-based receptors for the coordination of anions and cations." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386613.
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McKenna, Eugene Gerard. "The stereochemistry and mechanism of Wittig reactions of phosphonium and arsonium ylide anions." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335560.
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Jamal, Eddine Nour. "Reactivity of molecular anions at low temperature : implications for the chemistry of the interstellar medium ant Titan's atmosphere." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S132/document.
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Depuis leur découverte dans divers environnements astrophysiques, les anions polyyne CxH¯ (x = 2, 4, 6) et les anions cyanopolyyne CxN¯ (x = 1, 3, 5) ont reçu une attention considérable. Ces anions semblent jouer des rôles importants dans leur environnement. Cependant, les données à basse température sur les voies chimiques menant à leur formation et à leur destruction sont encore rares, en particulier ce qui concerne l'identité du produit et les ratios de ramification. Pour résoudre ce problème, nous nous sommes engagés dans la recherche de la réactivité de ces anions moléculaires en utilisant des instruments dédiés couplant des jets subsonique et supersonique avec des méthodes de spectrométrie de masse. De cette façon, nous avons étudié la réactivité des anions C3N avec le cyanoacétylène (HC3N) ainsi que la réactivité de CN¯, C3N¯, et C5N¯ avec l'acide formique (HCOOH) de 298 K à des températures aussi basses que 36 K. Nous rapportons dans ce travail le taux de vitesse, les produits, et les ratios de ramification de ces réactions. Ce travail aborde également la source prototype d'ions sélectionnée, qui a récemment été mis en place dans notre laboratoire afin d'étendre notre recherche à d'autres anions d'intérêt astrophysique (e.g. les anions CxH¯ et Cx¯). Une description de cet instrument ainsi que des résultats préliminaires sont présentés dans ce travail. Cette thèse, «Reactivity of Molecular Anions at Low Temperature: Implications for the Chemistry of the Interstellar medium and Titan’s atmosphere», a été réalisée au sein de l'Institut de physique de Rennes et de l'Ecole Nationale Supérieure de Chimie de Rennes. Mots-clés: astrochimie, atmosphère de Titan, anions moléculaires, cinétique en phase gazeuse, jet supersonique, spectrométrie de masse, source d’ions sélectionnéeEver since their discovery in various astrophysical environments, polyyne anions CxH¯ (x = 2, 4, 6) and cyanopolyyne anions CxN¯ (x = 1, 3, 5) have received a considerable attention. These anions appear to be playing important roles in their environments. However, low temperature data on the chemical pathways leading to their formation and destruction is still scarce, especially regarding product identity and branching ratios. To address this issue, we have engaged in the investigation of the reactivity of these molecular anions by employing dedicated instruments coupling subsonic and supersonic flows with mass spectrometry methods. In this fashion, we have investigated the reactivity of C3N¯ anions with cyanoacetylene (HC3N) as well as the reactivity of CN¯, C3N¯, and C5N¯ with formic acid (HCOOH) from 298 K down to temperatures as low as 36 K. We report in this work the rate coefficient, the nature of the products, and the branching ratios of these reactions.This work also addresses the prototype selected ion source in our laboratory, which was recently implemented in order to extend our investigation to other anions of astrophysical interest (e.g. CxH¯ and Cx¯ anions). A description of this instrument as well as some preliminary results are presented in this work. This thesis, «Reactivity of Molecular Anions at Low Temperature: Implications for the Chemistry of the Interstellar medium and Titan’s atmosphere», was carried out at the Institut de Physique de Rennes and the Ecole Nationale Supérieure de Chimie de Rennes.Keywords: astrochemistry, Titan’s atmosphere, molecular anions, gas phase kinetics, supersonic flow, mass spectrometry, selected ion source
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Sun, Weiguo. "Theoretical studies of electron-polyatomic-molecule scattering and photodetachment of molecular anions using ab initio methods /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487760357821831.
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Bain, David Leslie Kenneth. "Reactions of phosphide anions single electron transfer and routes to optically active phosphorus compounds." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356886.
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Blug, Matthias. "Phosphinines as Precursors for Phosphabarrelenes and Phosphinine Anions: Coordination Chemistry, Catalysis and Stabilisation of Nanoparticles." Phd thesis, Ecole Polytechnique X, 2009. http://pastel.archives-ouvertes.fr/pastel-00005638.
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Les phosphinines, analogues phosphorés des pyridines sont à la base de ce travail de thèse. La première partie de ce travail résume les différentes voies de synthèse de ces phosphinines, leurs propriétés électroniques ainsi que leurs diverses applications en catalyse. Différents ligands bidentates, tridentates et tétradentates ont pu être générés via l'attaque nucléophile d'organolithiens sur des phosphinines possédant des groupements ancillaires diphénylphosphine. De plus l'utilisation d'un complexe pinceur mono-anionique dérivé du diphénylphosphinométhane a été envisagée notamment dans le cadre de réactions ambitieuses telles que l'activation de liaisons C
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Wörsching, Matthias [Verfasser], and Wolfgang [Akademischer Betreuer] Schnick. "Synthesis and structural chemistry of subvalent compounds with complex anions / Matthias Wörsching ; Betreuer: Wolfgang Schnick." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1130587460/34.
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Kas, Milaim. "Cold chemistry of molecular anions: a theoretical investigation in the context of hybrid trap experiments." Doctoral thesis, Universite Libre de Bruxelles, 2018. https://dipot.ulb.ac.be/dspace/bitstream/2013/279061/4/main.pdf.
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Hybrid trap experiments are set-ups that allow to study the interaction between ions and atoms in cold controlled environment. In such context, molecular anions present specific theoretical and experimental interests and challenges. In this work, we have used extensive \textit{ab initio} methods to investigate several collisional anionic systems: (1) M + OH$^{-}$ (where M are alkali or alkaline earth atoms), (2) Rb and H + OH(H$_{2}$O)$_{n}^{-}$ (with $n=0,1,2,3,4$) and (3) Rb and Li + C$_{2}^{-}$. Several molecular properties such as vertical detachment energies or electroaffinities, optimized structures, harmonic frequencies, potential energy curves or surfaces, etc have been calculated using high level quantum chemistry approaches. The results have been used to make predictions on the related reactivity in low energy regime. We emphasis on electronic detachment processes by carefully analysing the difference between the neutral and anionic potential energy surface. The Rb + OH$^{-}$ system is currently under experimental investigation. Therefore, a detailed study of its reactivity is carried out in the present work. We have analysed the different reactive channels arising from both collision involving the ground state and first electronic excited state of Rb. Using our calculated potentials and a capture model based dynamics, we have extracted cross sections and rate constants. Comparison with other alkali and earth alkaline atoms are made. Hydrated hydroxide cluster anions are planned by the experimental group as upcoming studied systems. We present here our preliminary results on the possible outcome when considering collisions with Rb and we discuss their implications for hybrid trap experiments. We make comparison with H as a colliding partner and consider our results in the context of astrochemistry. Finally we propose the C$_{2}^{-}$ molecular anion as an alternative to OH$^{-}$. Its interaction and reactivity with Rb and Li are investigated and the results are used to motivate our suggestion. Furthermore, for the Rb+OH$^{-}$ and Rb+C$_{2}^{-}$ system, we have also investigated the effect of a non-thermal collision energy distribution on the rate constants. At last, in light of the discussions related to each topic, general conclusions on the use of molecular anions in hybrid trap experiments are drawn.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Blug, Matthias. "Phosphinines as precursors for phosphinine anions and phosphabarrelenes : coordination chemistry, catalysis and stabilization of nanoparticles." Palaiseau, Ecole polytechnique, 2009. https://pastel.archives-ouvertes.fr/pastel-00005638.
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Phosphinines, the phosphorus analogues of pyridines, are the common basis of the present thesis work here. In the first part, the various synthetic routes for the synthesis of phosphinines their electronic properties and their application in transition metal catalysis are summarized. Bidentate, tridentate and tetradentate ligands could be generated by the nucleophilic attack of organolithium reagents on phosphinines with pending diphenylphosphine groups. The use of monoanionic pincer complex derived from diphenylphosphinomethane ( dppm) was studied with special emphasis on the activation of poorly reactive moieties such as C-H bonds and on the dehydrogenation of borane adducts. The third part of this work, describes the synthesis of 3,5-substituted phosphinines via a desilylation method starting from the corresponding 2,6-(bistrimethylsilyl)phosphinines. The use of these 3,5-substituted phosphinines on the stabilization of metal(O)-transition metal (Au, Ni) nanoparticles was studied. In the last part of this work the use of phosphinines as precursors for the generation of bulky monodentate phosphines, the so called phosphabarrelens was studied. The electronic properties of these scarcely studied ligands was investigated experimentally and by the means of DFT calculations (CDA). The use of these ligands in coordination chemistry has allowed for the isolation of various coordination complexes of phosphabarrelenes with transition metals (Groups 9-11). Interestingly these ligands are sui table for the stabilization of highly unsaturated 14VE Pt(O) and Pd(O) complexes. These complexes could be successfully applied in cross-coupling and hydrosilylation reactionsLes phosphinines, analogues phosphorés des pyridines sont à la base de ce travail de thèse. La première partie de ce travail résume les différentes voies de synthèse de ces phosphinines, leurs propriétés électroniques ainsi que leurs diverses applications en catalyse. Différents ligands bidentates, tridentates et tétradentates ont pu être générés via l’attaque nucléophile d’organolithiens sur des phosphinines possédant des groupements ancillaires diphénylphosphine. De plus l’utilisation d’un complexe pinceur mono-anionique dérivé du diphénylphosphinométhane a été envisagée notamment dans le cadre de réactions ambitieuses telles que l’activation de liaisons C‒H peu réactives ou encore la déhydrogénation de boranes. La troisième partie de ce manuscrit décrit quant à elle la synthèse de phosphinines 3,5-substituées via désilylation à partir des 2,6-(bistriméthylsilyl)phosphinines correspondantes. L’utilisation de ces phosphinines 3,5-substituées pour la stabilisation de nanoparticules de métaux de transition (Au(0), Ni(0)) a elle aussi été étudiée. La dernière partie de ce travail est consacrée à la synthèse et à la caractérisation de phosphabarrélènes, ligands monodentates encombrés de type phosphine, obtenus à partir de phosphinines. Etant donné que les propriétés électroniques de ces ligands sont restées très peu décrites jusqu'à ce jour, des études expérimentales et théoriques ont été réalisées. Enfin, la chimie de coordination des phosphabarrélènes a été considérée et a permis de mettre en évidence divers complexes de métaux de transition (Groupes 9-11). De manière intéressante, ces ligands se sont montrés efficaces pour la stabilisation de complexes de Pt(0) ou Pd(0) hautement insaturés, ces derniers ayant été employés avec succès dans des réactions de couplage croisé ou d’hydrosilylation
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Higginson, Joshua J. "Synthesis and coordination chemistry of ditopic ligands capable of coordinating metal ions and interacting with anions." Thesis, University of Huddersfield, 2015. http://eprints.hud.ac.uk/id/eprint/26444/.
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The aim of this research was to synthesise a series of novel organic multidentate ligands which contain N-donor domains for the coordination of metal ions and amide or amine hydrogen atoms which are capable of interaction with anions. It was envisaged that incorporation of these two binding units would produce a system where the metal ions would control the ability of the ligand to interact with anions or vice versa. Ligand 1 contains a tetradentate N-donor domain formed by a central bipyridine, two thaizole units and two amide units attached in the 4,4’-position of the bipyridine unit. Reaction of this with divalent metal ions results in a mono-nuclear complex where the metal is bound by the N-donor atoms and the amides interact with a variety of anions. Reaction with monovalent metal ions results in the formation of a dinuclear double helicate with the metal again coordinated by the N-donor domains and the anions interacting with the amide hydrogen atoms. This results in a polymeric assembly in the solid state. Ligand 2 contains an identical tetradentate domain comprised of the same N-donor units; however the single amides in the 4,4’-position have been removed and a diamide attached in the 3,3’-position of the bipyridine unit. Reaction of [L2 with divalent cations results in a similar mono-nuclear species. The metal centre is coordinated by the N-donor atoms and one of the acetyl units from two adjoining ligands with the counter ions undergoing interactions with the diamide hydrogen atoms. Coordination of the same ligand with a monovalent cation resulted in a di-nuclear double helicate, each metal centre is fulfilled by the N-donor atoms of the ligand strand and the hydrogen atoms of the diamide units interact with anions. This too results in a polymeric assembly in the solid state. Ligands 3 and 4 contain the iso-structural tetradentate N-donor domain seen in [L1] and [L2] but their functionality in the 3,3’-position differ. Ligand 3 contains a urea group while ligand 4 has a single amide group attatched to an indole unit. Coordination of [L3] and a divalent metal ion results in the formation of a mono-nuclear species with the metal ion bound by the central bipyridine and the N-donor of two thaizole units. Furthermore each of the urea groups in the 3,3’-position undergo favourable interactions with the perchlorate counter ions. A solid state structure of Ligand 4 was only successful with a monovalent cation resulting in the formation of a dinuclear double stranded species. Each metal centre exhibits a distorted trigonal planar geometry through coordination with a pyridine and thiazole ring of one strand and a single thiazole ring of another. The indole and amide of each ligand strand undergo two sets of interactions; anion interactions through the amide and indole hydrogen atoms as well as complementary intermolecular interactions between the indole N···H units of one ligand and the carbonyl C···O units of another complex. Both [L3] and [L4] exhibit long range order through favourable anion-NH interactions however [L4] also displays complimentary indole/acetyl interactions to develop a larger aggregate species. In all these cases the resultant complex is independent upon which anion is used. However, this is not the case with ligand 5. Reaction of [L5] with Cu(BF4)2 or Cu(ClO4)2 gave a dinuclear double helicate with a cleft within the helicate assembly in which an anion is bound. However, reaction of this with half an equivalent of either sulphate (SO4 2-) or dihydrogen phosphate (H2PO4 -) results in the formation of a different dinuclear double helicate whereby the cleft is occupied by either a dihydrogen phosphate or sulphate anion which bridges the metal centres. Further addition of sulphate results in no change of the ESI-MS indicating the dinuclear double helicate persist however addition of one equivalent of di-hydrogen phosphate leads to the formation of a pentanuclear circular helicate. Each metal centre is coordinated by the pyridine and thiazole units of two different ligand strands and a single Cu···O interaction from one of the dihydrogen phosphates. The inclusion of three dihydrogen phosphates into the centre of the assembly as well as a series of phosphate-ligand and phosphate-phosphate interactions leads to the dimerization of the structure with another set of phosphates from a second assembly. Further reaction of this dinuclear species with one equivalent of (Bu4N)NO3 resulted in the formation of a hexanuclear circular meso-helicate (or mesocate). In this structure each Ndonor domain of a thiazole and pyridine ring coordinate two different Cu2+ metal centres. Each metal centre exhibits a distorted octahedral arrangement with two ligand strands completing 4 of its 6 coordination sites, the remaining sites are occupied by two O-donors of a nitrate anion. In addition an amine of each ligand strand points into the centre of the complex creating a cavity capable of hosting two nitrate anions. Ligand 6 is made up of the same bis-bidentate donors as ligand 5 with the addition of a nitrogen atom into the central phenyl spacer. On reaction of [L6] with a divalent metal ion (e.g. Cu(II)) a simple mono-nuclear structure is observed. Although a mono-nuclear assembly is expected, it is interesting that even a simple change in the ligand strand can have a dramatic affect on the self-assembly process. When a central 1,3-phenylene spacer is employed (i.e. [L5]) a dinuclear double helicate is formed, however, when a 1,3-pyridine unit is contained within the ligand strand (i.e. [L6]) a simple mono-nuclear species is produced.
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Flint, Nicholas John. "A study of linewidth variation in the E.S.R. spectra of some radical anions." Thesis, Lancaster University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329999.
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Pushina, Mariia. "Sensing of Anions, Amines, Diols, and Saccharides by Supramolecular Fluorescent Sensors." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1558539245401457.
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Payne, Martin William. "Investigation of the reactivity of [HM?(CO)??]? (M = Ru, Os) clusters : kinetics of ¹³CO exchange, effects of ion pairing, and the relationship between the ¹³CO exchange and the catalysis of the water-gas shift reaction /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487332636477575.
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De, Bernardin Paolo. "Preparation and physico-chemical characterization of supramolecular fluoride receptors based on uranyl-salophen complexes incorporated within micelles." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209671.
Full textAbstract:
The development of selective and sensitive sensors for anionic species in water is a growing field of research. In particular, the detection of fluoride in aqueous samples is of great interest because of health related problems attributed to this anion. Furthermore its small size and its high hydration energy make it a particularly challenging species to recognize in water.
Uranyl-salophen receptors have shown to be good receptors for this anion in organic solvents due to their hard Lewis acid character which makes them good binders for the hard Lewis base fluoride. However they are not water soluble.
The incorporation of uranyl-salophen receptors 1-3 within cationic micelles (CTABr and CTACl) will make them “water-compatible” and give us the possibility to study the behaviour of these system in water. The 3 receptors shown
in figure 1 were studied in this thesis. Preliminary work had already been reported on receptor 1 in CTABr micelles. Binding affinities studies showed that these receptors have binding constants for fluoride of the order of 104 M−1 which is two orders of magnitude higher than
the value obtained for the same receptors in a less competitive solvent such as methanol. This suggests that the micellar environment has an effect, not only on the solubility of the receptors in water, but also for the binding process.
Physico-chemical studies were undertaken on the system in order to obtain some structural informations. Dynamic Light Scattering experiments showed an increase in the size of the CTABr micelles upon receptor’s incorporation but not on the CTACl ones.
NMR studies, including chemical shift variation measurements, nOe and Paramagnetic Relaxation Enhancement (PRE) experiments, were undertaken in order to analyse the location and orientation of the receptors in the micelles. Results indicate that receptor 1 is located at the micellar surface, in CTABr micelles and a little deeper in CTACl micelles, orienting the receptors binding site towards the exterior of the micelle. Receptor 2 is more buried inside the micelles compared to receptor 1 but with a similar orientation. Receptor 3 is the most deeply buried
in the micelles, and the experiments suggests that no preferential orientation is adopted.
A systematic study of the factors affecting PRE measurements was also undertaken showing the dependency of this measurements on the surfactant concentration, the nature of the counterion and the ionic force. A method, based on the normalization of the relaxivity values to the value obtained for the micelle polar head is proposed in order to avoid all the variations due to the experimental conditions and thus enabling the comparison of different systems.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished