Dissertation (Ph.D.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (p.113-125).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 199-214). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

This thesis describes the synthesis of macrocyclic and interlocked receptors which exploit halogen- and hydrogen-bonding intermolecular interactions for anion recognition. <strong>Chapter One</strong> introduces the field of supramolecular chemistry, with particular focus on applications of host–guest chemistry to anion coordination and anion templation in the construction of mechanically interlocked molecules. <strong>Chapter Two</strong> details the synthesis of a series of cyclic and cage-like porphyrin-based receptors which bind anions through halogen- and hydrogen-bonding interactions. The ability of these receptor systems to bind and sense anionic guest species is investigated and comparisons between hydrogen- and halogen-bonding are discussed. <strong>Chapter Three</strong> reports anion-templated pseudorotaxane assemblies stabilised by both halogen- and hydrogen-bonding. The related catenanes are also prepared and their affinity for anions is investigated. The first examples of interpenetrated and interlocked architectures constructed by a single charge-assisted halogen bond are also reported. <strong>Chapter Four</strong> describes the synthesis of a 1,3-dialkyl-1,2,3-triazolium-containing threading component, whose anion binding properties are studied and compared with other threading molecules. The ability of this novel thread to form pseudorotaxanes is investigated and the preparation of the related rotaxane species is outlined. <strong>Chapter Five</strong> discusses attempts to prepare rotaxanes with improved anion binding affinities through increasing the lipophilicity of the anion binding clefts. Several novel rotaxanes are described and their anion binding properties are probed. <strong>Chapter Six</strong> describes the experimental procedures used in this work and the characterisation of compounds presented in chapters two to five. <strong>Chapter Seven</strong> summarises the conclusions of this thesis.

Abstract Major water soluble ions (Cl-, NO3-, SO42-, CH3SO3-, Na+, K+, NH4+, Mg2+, Ca2+) were determined and the results interpreted from a 121 m long ice core drilled at the summit of the Lomonosovfonna dome, Svalbard. The core covers about the past 800 years. The reliability of anion chemistry for paleoenvironmental studies, and various insoluble particles were also investigated. The ice core studied in this Thesis is the first relatively deep ice core from the central Svalbard that has been analyzed and the results interpreted and published at high resolution for all major ions. One of the clearest features of the ion profiles is anthropogenic impact. SO42- and NO3- concentrations show significant increases by the mid-20th century with slight increases already at the end of the 19th century. In addition excess Cl- and NH4+ from anthropogenic sources are detected arriving after the mid-20th century. Anthropogenically derived SO42- and NO3- have different sources on Lomonosovfonna. NO3- is correlated with NH4+ and requires interpretation in terms of both natural and anthropogenic NH4NO3 sources. The ice core ionic load consists mostly of sea salt ions (Na+, Cl-, K+ and Mg2+). Water soluble Ca2+ are mostly terrestrial in origin. Ion balance together with the Na+/Cl- ratio shows considerable change about 1730 that is most probably due to Na2CO3 input to the ice cap before 1730. Marine biogenic CH3SO3- concentrations are high and stable during the Little Ice Age. CH3SO3- concentrations show a clear change in concentrations in 1920, that is the end of the Little Ice Age in Svalbard. Regardless of anthropogenic impact, marine biogenic SO42- is appreciable in total SO42- budget even in the 20th century. The Laki volcanic eruption in Iceland in 1783 is identified in the ice core as a volcanic tephra layer and high SO42- concentration and acidity peaks. These show that SO42- arrived to the Lomonosovfonna ice cap 6–12 months later than insoluble tephra and the SO42- aerosol caused a drop in temperature. The reliability of ice core ion chemistry analyses was estimated – for the first time in an ice core using two different analytical procedures on 500 adjacent samples from the same depth. Small-scale inhomogeneity in ion concentrations shows that information from ice core layers is representative of the regional environmental and suitable for paleoclimate studies.

This thesis describes the synthesis of interlocked anion host systems which exploit hydrogen bonding, halogen bonding, and lanthanide-coordination for anion recognition and sensing in aqueous solution. Chapter 1 introduces the field of anion supramolecular chemistry, with particular focus on areas of particular relevance to this thesis, namely anion recognition and sensing, anion templation and the synthesis of interlocked structures. Chapter 2 describes the synthesis of hydrogen bonding rotaxane and catenane hosts for recognising and sensing oxoanions in aqueous solvent media. The novel use of nitrate anion templation for the synthesis of interlocked molecules is reported, and the unprecedented selective recognition of nitrate in aqueous solvent media is demonstrated. Chapter 3 details the preparation of water soluble permethylated β-cyclodextrin-stoppered rotaxane hosts that utilise halogen bonding and hydrogen bonding interactions to bind anions in pure water. The first thermodynamic investigation into halogen bonding in water is reported, and the relative capabilities of halogen and hydrogen bonding for anion recognition in water are compared. Chapter 4 investigates the incorporation of lanthanide cations into rotaxane hosts for optical anion sensing. The seminal use of lanthanide cation templation for interlocked molecule synthesis is described, before anion templation approaches towards the synthesis of lanthanide-based rotaxanes are discussed. The luminescence anion sensing capabilities of these interlocked hosts are investigated. Chapter 5 describes the experimental procedures used in this work, and details the characterisation of compounds presented in Chapters 2–4. Chapter 6 summarises the conclusions of this thesis.

The aim of thesis was to establish a methodology for 210Pb measurements by Accelerator Mass Spectrometry (AMS). The potential application is to measure 210Pb in people who have been exposed to radon. This will better our understanding of radon toxicity, which is not possible now with current radiometric and mass spectrometry techniques. The determination of 210Pb by AMS was done in two major studies 1) Studying Pb chemistry in a Cs+ sputter source used in AMS and 2) Evaluating 204,205 & 208Pb spikes for the quantification of 210Pb by isotope dilution. Pb chemistry was investigated using an 834 SIMS-type and a SO-110 Cs+ sputter source at the IsoTrace Laboratory and A.E Lalonde AMS facility, respectively. Different molecular anions of Pb were studied with the 834 SIMS-type Cs+ sputter source and the strongest molecular anion current of Pb and thus greatest ionization efficiency was achieved form the superhalogen PbF3-. The average 208PbF3- current was unaffected by varying the ratio of the fluorinating compounds (AgF2 and CsF) packed into a target. The average current of 208PbF3- was reproducibly increased by chemically mixing the targets of AgF2, CsF and PbF2 in concentrated HF rather than mechanically mixing them the powders with a stir rod. The count rate of 210Pb reproducibly increased by a factor of 20 when μg quantities of PbF2 were present in mg AMS targets compared to AMS targets that had pg quantities of PbF2. The average current of 208PbF3- for pure PbF2 targets in an SO-100 Cs+ sputter source was reproducibly increased when the Cs+ flux was decreased by a factor of 10. This phase of my work maximized the overall efficiency of PbF3-, to a value of 1.8x10-10 ±8x10-11s-, which was a key first step in the measurement by AMS. Then isotope dilution was tested to quantify 210Pb and the next stage of my work evaluated the use of 204,205 & 208Pb spikes. 210Pb was measured in the +3 charge state by isotope dilution assays using 204,205 & 208Pb spikes. 204Pb+3 reproducibly suffered from the molecular interference from 68Zn3+3, which could not be easily removed without negatively impacting the detection limit for 210Pb. 205Pb+3 continually suffered from 205Tl+3 interference which could be readily be removed but not without negatively affecting the II detection limit for 210Pb. 208Pb+3 suffers from no molecular interferences but if a large amount of 208Pb is needed to swamp the Pb in a sample, this could limit the detection limit for 210Pb as the abundance sensitivity is 210Pb/208Pb=1.3×10-12. A calibration curve is required when 208Pb is used as a spike due to a difference in collection efficiency of a Faraday cup, where 208Pb+3 is detected and the gas ionization chamber, where 210Pb+3 is detected. The quantification of 210Pb with 208Pb as a spike yielded a detection limit of 4.4mBq at the IsoTrace facility. A theoretical detection limit of ≤0.11mBq is expected at the A.E Lalonde AMS facility. The expected detection limit at the A.E Lalonde AMS facility is on par with α-spectroscopy but AMS samples can be counted in less than 1 hour whereas alpha spectrometry samples must be counted for about 1 day.

It is the purpose of this paper to present a detailed account of the design and construction of this positive-ion source and associated equipment.