Thesis (Ph. D.)--University of Wisconsin--Madison, 1950. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 69-70).

Metal chalcogenides form an important class of inorganic materials, which include several technologically important applications. The design of metal chlcogenides is of technological interest and has encouraged recent research into moderate temperature solid-state synthetic methods for the single crystal growth of new materials. The aim of this project is the investigation and development of synthetic methodology for the synthesis of novel metal chlcogenides. The new inorganic compounds of the type “M(AlS2)(GeS2)” (M = Na and K) are new metal-chalcogenides, synthesized by the classical solid state approach. The characterization of these compounds was carried out by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Single crystal and powder X-ray diffraction, solid state Nuclear Magnetic Resonance (NMR), Ultraviolet-visible (UV-VIS), Infrared (IR) and Raman spectroscopy. These theses study the synthesis of metal chalcogenides through the use of standard chemical techniques. The systematic studies demonstrate the effect of the reactants ratio and reaction temperature on the synthesis and growth of the single crystals. Metal chalcogenides have several potential applications in gas separation, ion exchange, environmental remediation, and energy storage. Especially, the ion exchange materials have found possible applications in waste-water treatment, water softening, metal separation, and production of high purity water.

no / The structure of C16H10N4O4[HCl,1.5CH3OH], Mr = 406.80, has been determined from X-ray diffraction data. The crystals are monoclinic, space group C2/c, with eight molecules per unit cell and a = 21.482(4), b = 7.131(1), c = 24.495(5) A ° , b = 111.01(3) , crystal density Dc = 1.546 g/cm3. The material was difficult to crystallize and crystals produced were found to be poor diffractors. Intensity data were measured at liquid nitrogen temperature using a weakly diffracting crystal typical of the batch. However the X-ray analysis has finally enabled the chemical constitution of this cryptolepine derivative, which was previously incorrectly assigned, to be unequivocally established. Direct methods were used to solve the structure which was refined by full-matrix least squares to a conventional R-index of 0.0798 for 2,861 reflections and 268 parameters. The 7,9-dinitrocryptolepine molecule is highly planar with a strong intramolecular hydrogen bond between N(10) in ring C and O(92) of a nitro group. There are a number of intermolecular hydrogen bonds involving the cryptolepine derivative the hydrochloride and both solvated methanols. One of the methanol solvate molecules (methanol 2) is unusually disordered with its C atom lying exactly on a crystallographic twofold axis. Consequently the methanol OH and H3 groups are at 0.5 occupancy and repeated by the twofold symmetry.

No / A hybrid molecular mechanics and quantum mechanics solid state DFT method is used to re-rank the stability of racemic and enantiopure crystal structures of four molecules; 4-hydroxymethyl-2-oxazolidinone, 5-hydroxymethyl-2-oxazolidinone, 2-(4-hydroxyphenyl)-2,5,5-trimethylpyrrolidine-1-oxy and 2-(3-hydroxyphenyl)-2,5,5-trimethylpyrrolidine-1-oxy. Previous work using a force field based method to predict these crystal structures indicated that the lattice energy may be a suitable criterion for predicting whether a chiral molecule will resolve spontaneously on crystallisation. However, in some cases, the method had predicted an unrealistically high lattice energy for the structure corresponding to the experimentally observed one. The Hybrid DFT method successfully predicts those molecules which resolve spontaneously and furthermore predicts satisfactory lattice energies for all experimentally observed structures. Based on a comparison of the predicted lattice energies from the two methods it is concluded that the force fields used were not sufficiently accurate to predict spontaneous resolution with any confidence. However, the Hybrid DFT method is shown to be sufficiently accurate for making such predictions.

<p> The structure of one of the complexes of rhenium (V) is discussed in this work, namely,[ReOOH(en) 2] (ClO4)2. Chapter I, the Introduction, surveys some of the recent work on rhenium complexes and introduces the basic problems. Chapter II contains a summary of most of the relevant theory for crystal structure determinations. The partial solution of the structure is given in Chapter III entitled Experimental. This section concludes with a discussion of the ambiguity of the actual space group, the ambiguity being whether the space group is P1, or P1. Chapter IV summarizes and discusses the results obtained and compares them with other known results. Anomolous dispersion and neutron diffraction are suggested as possible means for complete solution.</p> / Thesis / Master of Science (MSc)

The research summarized in this dissertation is aimed at the design and exploratory synthesis, characterization, and property investigation of lanthanide-based functional materials. The substances prepared in this work, including small molecular complexes and nanostructured particles, are of fundamental scientific interest as well as practical significance due to the unique chemical and physical properties of the lanthanide elements. Envisioned applications include their uses as light-emitting materials in modern display technology, optical amplifiers, and high-density magnetic recording media. This research seeks to develop general methods for directing the formation of lanthanide materials, particularly as a means of influencing the physical properties of such materials. These efforts are elaborated in distinct yet related projects.In Chapter 2, exploratory synthesis, structural characterization, and photo-physical investigation of adducts of lanthanide &amp;#946;-diketonates with a tridentate neutral ligand, TPTZ are described.In Chapter 3, analogous studies utilizing p,p'-disubstituted bipyridine and phenathroline type bidentate neutral ligands are detailed. The structures of the complexes have been established by single crystal X-ray diffraction. Compositional and structural differences among the various complexes are caused by different structural and electronic properties of the ligands and overall steric compactness of the coordination sphere. Red and green luminescence characteristics of Eu(III) and Tb(III) ions are observed for the corresponding complexes, upon UV excitation, consistent with the well-established ligand-mediated energy transfer and light emission mechanism.In Chapter 4, the electroluminescence properties of various europium complexes are evaluated for their potential as emissive materials in organic light-emitting diodes.The synthesis and characterization of Er-doped LaPO4 nanoparticles are described in Chapter 5 together with the preparation and studies of hybrid nanocomposites composed of nanoparticle-doped sol-gels. A single-mode waveguide system was fabricated, wherein Er-doped nanoparticles solubilized in a sol-gel matrix has shown promising performance in propagating light signals (1.54 µm) without significant optical losses.In Chapter 6, synthesis, electron microscopic characterization and magnetic studies of crystalline Sm(III)- and Eu(III)-doped Fe3O4 nanoparticles are detailed. Magnetic studies suggest the ferromagnetic behavior of the lanthanide-doped Fe3O4 nanoparticles at room temperature and therefore, the significant effects of lanthanide doping.

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A series of complexes of the type [Rh(diphos)(C(_7)H(_8))](BF(_4)) (1) have been synthesised and two of these species [diphos = Bu(^1)(_2)P(CH(_2))(_2)PBu(^1)(_2), Cy(_2)P(l,2-trans-cyclopentane)PCy(_2)] have been characterised by X-ray crystallography. The influence of the chelating diphosphine on the structural characteristics and NMR parameters of these compounds has been investigated. Complexes of the type (1) are active catalysts for the hydroformylation of l-hexene(120ºC, 450psi 2:1 H(_2):C0). However, they are inactive for the related hydroesterification process and this is attributed to the stability of [Rh(diphos)(CO)(_2)]^ under the reaction conditions. Detailed studies of the reactions of type (1) complexes with H(_2) have been undertaken. The products from these reactions are dependent on both the diphosphine and the solvent employed. In THF and CD(_2)Cl(_2), dimeric hydrides were observed, whilst in CDCl(_3) hydrido-chloro-complexes of the type [Rh(_z)(diphos)(_2)(|µCl)H(_2)](^2+) were formed. In the former solvents, three types of hydrides have been identified by NMR studies, namely [Rh(_2)(diphos)(_2)H(_6)], [Rh(_2)(diphos)(_2)H(_4)] and [Rh(_2)(diphos)(_2)H(_4)](^2+). The oxidative-addition reactions of alkyl-, acyl- and formyl-halide with Rh(I) complexes have been investigated. The reaction with ClCO(_2)Me with [Rh(dppe)Cl](_2) and [Rh(dppe)](_2)(BF(_4))(_2) led to the formation of diphosphine-rhodium(III)-halide species (H(_3)NOH)[Rh(dppe)Cl(_4)] and [Rh(_2)(dppe)(_2)(µ-Cl)(_3)Cl(_2)](BF(_4)) respectively. Alternative routes to these complexes have been investigated starting from RhCl(_3).3H(_2)O/diphosphines and a series of the novel halide bridged dimers have been characterised, including by X-ray crystallography and their reaction chemistry explored. In the synthesis of the cationic rhodium complexes from neutral chloro-complexes with AgBF(_4), the novel silver complexes [Ag(_2)(µ-Bu(^t)(_2)P(CH(_2))(_3)PBu(^t)(_2))(_2)](BF(_4))(_2), [{Ag(H(_2)O)}(_2)(µ-Bu(^t)(_2)P(CH(_2))(_2)PBu(^t)(_2))](BF(_4))(_2), and [Ag(C(_6)D(_6))(_3)BF(_4)] have been isolated as by-products and characterised by X-ray crystallography.