Дисертації з теми "Clathrate compounds"
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1
Nohako, Kanyisa. "Immunosensors developed on clathrate platform compounds." Thesis, University of the Western Cape, 2013. http://hdl.handle.net/11394/4428.
Анотація:
Philosophiae Doctor - PhDOrganic noncyclic compounds were used in the development of immunosensor for rapid fish species detection. Flourene derivatives show unique chemical and physical properties because they contain a rigid planar biphenyl unit, and the facile substitution at C9 position of the flourene can improve the solubility and processability of materials containing flourene without significantly increasing of steric interactions in the compounds backbone. 9-(4- methoxyphenyl)-9H-xanthen-9-ol is bulky, rigid and has an hydroxyl moiety that may act as a hydrogen – bond donor, as well as a pyranyl oxygen which is a potential hydrogen –bond acceptor. We have successfully synthesised 9,9’-(ethyne1,2-diyl)bis(flouren-9-ol) by reflux method and 9-(4-methoxyphenyl)-9H-xanthen-9-ol through stirring at room temperature. The products were characterised using spectroscopic methods and were found to be both UV/Vis active (λmax = 400 nm flourene derivative and λmax = 337 nm xanthene derivative ) and fluorescent (440nm and 467nm flourene derivative and 344 and 380 xanthene derivative). These compounds were drop coated onto commercial glassy carbon electrode (GCE) to produce thin films. Scan rate dependent cyclic voltammetry (CV) confirmed the electrodynamics of the thin films to be consistent with monolayer diffusion (De = 1.37x10-21 cm2/s flourene derivative and De = 9.79x10-21 cm2/s xanthene derivative). Surface concentration was estimated to be 1.55x10-13 mol cm-2 flourene derivative and 2.00x10-13 mol cm-2. These compounds were used for the inclusion of parvalbumin antibodies immobilised onto clathrate platform by incubation and were evaluated as immunosensors for fish species identification. The antibody/antigen binding event was evaluated using UV/Vis spectroscopy, electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). The immunosensor response to parvalbumin in real samples of snoek (an indigenous fish species), tuna, fish paste, eyeshadow, lipstick, omega 3&6 and Scott's emulsion was evaluated. The sensitivity as calculated from EIS for each immunosensor was found to be 5.36x104 flourene derivative immunosensor and 4,11x104 xanthene derivative immunosensor and the detection limit of 1.50 pg/ml flourene derivative immunosensor and 2.42 pg/ml xanthene derivative immunosensor. The antibody/antigen binding was monitored as decrease in charge transfer resistance and increase in capacitance by EIS. The interfacial kinetics of the immunosensors were modelled as equivalent electrical circuit based on EIS data. The UV/Vis spectroscopy was used to confirm the binding of the antibody/antigen in solution by monitoring the intensity of the absorption peak.
2
Bentien, Anders [Verfasser]. "Transport and magnetic properties of rare-earth containing clathrates and clathrate-like compounds / Anders Bentien." Aachen : Shaker, 2005. http://d-nb.info/1181619599/34.
3
Harvey, Grant Andrew. "Structure and reactivity of diol host-guest compounds." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/17286.
Анотація:
Includes bibliographical references.The crystal structures of trans-9, 10-dihydroxy-9, 10-diphenyl-9, 10- dihydroanthracene with various guest molecules have been determined by X-ray diffraction. The guests were 2-butanone, 4-vinylpyridine, 4-methylpyridine and 2-methylpyridine. The host to guest ratios were determined by microanalysis and density measurements. The change of the overall host lattice structure upon guest release was studied by X-ray powder diffraction. The thermal characteristics of the compounds were studied using thermogravimetric analysis and differential scanning calorimetry. Guest desorption from three of the four compounds occurred in a single step whereupon the host framework collapsed back to the guest-free structure. The compound containing 4-methylpyridine, released the guest molecules in a two-step process. Evidence of a new host phase was identified from the XRD pattern of this intermediate phase. On further guest release, the intermediate phase converted to the guest-free host structure. In an attempt to reconcile thermodynamics with structure, the correlation between hydrogen bond length and guest desorption enthalpy was investigated.
4
Lavelle, Laurence. "Selective criteria in Werner clathrates." Thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/23608.
Анотація:
We have elucidated the structures of a series of Werner Clathrates with systematically changing guest molecules. The host is the inorganic coordination compound bis(isothiocyanato)tetra(4-vinylpyridine)nickel(II), [Ni(NCS)2(4-ViPy)4]. The guests are mixtures of tetrahydrofuran and the cyclic hydrocarbons: cyclohexane, cyclohexene, 1,3-cYclohexadiene, 1,4-cyclohexadiene and benzene. Host to guest ratios were elucidated by density and proton nuclear magnetic resonance spectroscopy. The thermal characteristics of the compounds were analysed by thermogravimetric analysis and differen.tial thermal analysis. The structures of two related compounds [Ni(NCS)2(Py)4] and [Ni(NCS)2(Py)4].nbenzene were also studied.
5
Dahn, Douglas Charles. "Low temperature specific heat of LixNbS2 intercalation compounds." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25563.
Анотація:
This thesis describes a study of the low temperature specific heat of LiⅹNbS₂, where x is between 0 and 1. Samples were prepared by intercalating lithium into niobium disulfide in electrochemical cells. Structural data obtained by x-ray diffraction are presented. These, together with electrochemical measurements, show that staged phases exist for some values of x. The electronic specific heat of LiⅹNbS₂, is consistent with complete charge transfer from the intercalated lithium to the bands of the NbS2 host. The lattice specific heat also shows large changes as a function of x. A discussion of the data in terms of continuum elasticity theory suggests that intercalation produces large changes in the shear elastic constant C₄₄ . A brief discussion of superconductivity in LiⅹNbS₂, is also included.Science, Faculty of
Physics and Astronomy, Department of
Graduate
6
Sayed, Amina. "Synergistic effects in clathrate selectivity." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/747.
Анотація:
Thesis (MTech (Chemistry))-- Cape Peninsula University Technology, 2012The inclusion behaviour of a series of hydroxyl hosts with a variety of liquid guests has been investigated. The host 9-(4-methoxyphenyl)-9H-xanthen-9-ol (A1), C20H16O3, forms inclusion compounds with aniline (ANI), 3-picoline (3PIC), morpholine (MORPH), Nmethylacetamide (NMA) and N-methylformamide (NMF). Their structures have been elucidated and correlated with their thermal behaviour. The inclusion compounds A1ANI and A1MORPH were successfully solved in space group P21/c, whereas A13PIC was solved in 𝑃ī. Non-isothermal kinetics of desolvation were performed for A13PIC and A1MORPH. The packing of A13PIC and A1MORPH is characterized by (Host)(Guest) hydrogen bonds, whereas A1ANI is stabilised by (Host)(Host) hydrogen bonding. Three structures were obtained for the host A1 and the guest N-methylacetamide, with structural formulas of C20H16O3 C3H7NO (A1NMA), C20H16O3 2C3H7NO (A12NMA) and 2C20H16O3 2C3H7NO (2A12NMA). The packing of A1NMA, A12NMA and 2A12NMA are characterized by (Host)-OHO-(Guest) and (Guest)-NHO-(Guest) hydrogen bonds, which gave hydrogen bonding patterns of 𝐶2 2(7), 𝐶3 3(11) and 𝐶4 2(11) respectively. The hydrate A1NMFH2O was successfully solved in the triclinic space group 𝑃ī. The A1NMFH2O hydrogen bond pattern may be described according to Etter’s notation as 𝑅4 2(8) and 𝑅6 6(16). The host 9-(3-methoxyphenyl)-9H-xanthen-9-ol (A2), C20H16O3, forms inclusion compounds with morpholine (A2MORPH), N-methylacetamide (A2NMA) and N-methylformamide (A2NMF), with host-guest ratios 1:1. The crystal structure of the apohost was solved in Pbca with Z=8. The structures of A2MORPH and A2NMF were solved in 𝑃ī, whereas A2NMA was solved in P21/n. The packing of these structures is stabilised by (Host)(Guest) hydrogen bonds. The host 5-(4-methoxyphenyl)-5H-dibenzo[a,d]cyclohepten-5-ol (A26), C22H18O2, forms inclusion compounds with aniline (A26ANI) and morpholine (A26MORPH). A26MORPH and A26ANI crystallised in the space groups Pc and 𝑃ī respectively. The packing of these structures are characterized by (Host)-OHO-(Host) hydrogen bonding. A guest exchange reaction was performed. The host compounds 5-(4-chlorophenyl)-5H-dibenzo[a,d]cyclohepten-5-ol (C21H15OCl), 5-[3(trifluoromethyl)phenyl]-5H-dibenzo[a,d]cyclohepten-5-ol (C22H15OF3) and 5-(naphthalen-1-yl)-5H-dibenzo[a,d]cyclohepten-5-ol (C25H18O) form inclusion compounds with morpholine. All three structures were solved in 𝑃ī with the host molecules hydrogen bonded to the morpholine guests.
7
Peek, Mary Elizabeth. "Crystal structures of DNA*bis-intercalator complexes." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/27122.
8
Jin, Pei-Wen. "Synthesis and Structure of Polynitro- and Polymenthylpolycyclic "Cage" Monomers and Polymers." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc332109/.
Анотація:
The objective of this study was to synthesize and characterize new energetic polycyclic "cage" compounds.
As part of a program involved in the synthesis of new polynitropolycyclic compounds, 2,6-dinitro-5-methoxy-
7-carbomethoxypentacyclo[5. 3 .0 . 0* • * . CP • i ° . 0* •8]decane has been synthesized. This is a model system which can be used to study (1) the effect of nitro substitution on the photolability of carbon-carbon double bonds and (2) to develop methods for avoiding Haller-Bauer cleavage in cage /3-keto esters when synthesizing polynitro-substituted cage compounds.
9
Taylor, Michael William. "Structures of Werner clathrates." Doctoral thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/22139.
Анотація:
This work is predominantly devoted to the 4-phenylpyridine ligand and the role that it plays in the formation of a series of inorganic coordination complexes termed Werner Clathrates. The synthesis and characterization by single crystal X-ray diffraction techniques are reported for 18 structures, the majority of which, upon crystallization, have the ability to include solvent or guest molecules within the host framework. The compounds are divided into four broad classes with the host complex of each as follows: Class A [Ni(NCS)₂(4-PhPy)₄]; Class B [NiCl₂(4-PhPy)₄]; Class c [Ni(NCS)₂(4-MePy)₂(4-PhPy)₂]; Class D [NiX₂(dmso)₂(4-PhPy)₂] where X= Ncs- or Cland [Ni(NCS)₂(4-RPy)₄] where R = 4-t-Bu or 4-Bz. The guest molecules, anionic ligand and substituent on the pyridine ligand have all been varied to try to establish the role that they each play in the formation of a structure. Much effort has been spent on the location and refinement of disordered guest molecules. Use has been made of statistical disorder and molecular scattering factors to try and successfully model these guests. The shapes of the cavities containing the guest molecules have been mapped by volume calculations and comparisons made between the packing of the compounds. Several of the complexes pack in space groups which are subsets of others and attempts have been made to determine the cause of the reduction in symmetry. A new technique to analyze competition experiments, with two guest solvents competing for occupation of the voids within the host lattice, has been established. Preliminary results for competition between p-xylene/benzene, p-xylene/toluene and p-xylene/ethylbenzene with the host complex [Ni(NCS)₂(4-ViPy)₄] are reported. The ability of the host complex [Ni(NCS)₂(4-MePy)₂(4-PhPy)₂] to separate a series of straight chain alcohols is demonstrated. The preference, by this host complex, for guest molecules containing a linear skeleton of 5 non-hydrogen atoms, is explained in terms of potential energy and residual volume calculations. Thermal analysis, consisting of thermogravimetry and differential thermal analysis, has been performed on several of the compounds. Temperatures of guest release, host decomposition and the enthalpies involved at each of these steps are reported.
10
Moore, Madeleine Henrietta. "Structure-activity relationships in Werner clathrates." Doctoral thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/17038.
Анотація:
Includes bibliographical references.The synthesis and characterization of a series of inorganic coordination compounds which, upon crystallization, have the ability to include solvent or guest molecules spatially within the lattice are reported. The compounds have the following general formula: [NiX2B4] - where X is isothiocyanate or bromine and B is 4-ethylpyridine, 4-vinylpiridine or 3,5-dimethylpyridine; [NiX2B2]n - where X is isothiocyanate, B is 2-aminopyridine and n indicates it is a polymer; [NiX2AB2]2 - where X is isothiocyanate, B is 3-aminopyridine (two of these four ligands in the dimer are bridging) and A is water. The various guest molecules have been carefully chosen, according to their point symmetry, which is a key factor in yielding structures of a particular type. The structures of seventeen compounds have been elucidated by single crystal x-ray analysis. The difficulty has been found to lie in refining disordered guest molecules. Other techniques employed in the initial characterization of these compounds are Microanalysis, Mass Spectrometry and UV/Visible Spectrophotometry. An intramolecular potential energy study on the [Ni(NCS)2(3,5-diMepy)4] complex reveals that the orthohydrogens on the 3,5-dimethylpyridine ligands control the conformation of the molecule. Packing densities and volume comparisons of the [Ni(NCS)2(4-Etpy)4] and [Ni(NCS)2(4-Vipy)4] complexes and their clathrates have been carried out. The exact sizes and shapes of the cavities in which the guest molecules are located in the x-ray crystal structures have been evaluated by both intermolecular potential energy and molecular volume calculations. Thermodynamic and spectroscopic properties of the [Ni(NCS)2(4-Etpy)4] and [Ni(NCS)2(4-Vipy)4] clathrates have been studied in both solution and the solid state. The techniques used are x-ray powder diffractometry, IR spectroscopy and Thermogravimetry (including Differential Thermal Analysis).
11
Clarke, Ronald James. "Kinetic and equilibrium studies of cyclodextrin-azo dye inclusion complexes /." Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phc5992.pdf.
Анотація:
Thesis (Ph. D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1985.Offprints of two author's journal articles inserted at end of the v. Includes bibliographical references (leaves 10-12).
12
Hughes, Thomas John. "Plug Formation and Dissociation of Mixed Gas Hydrates and Methane Semi-Clathrate Hydrate Stability." Thesis, University of Canterbury. Chemical and Process Engineering, 2008. http://hdl.handle.net/10092/1579.
Анотація:
Gas hydrates are known to form plugs in pipelines. Hydrate plug dissociation times can be predicted using the CSMPlug program. At high methane mole fractions of a methane + ethane mixture the predictions agree with experiments for the relative dissociation times of structure I (sI) and structure II (sII) plugs. At intermediate methane mole fractions the predictions disagree with experiment. Enthalpies of dissociation were measured and predicted with the Clapeyron equation. The enthalpies of dissociation for the methane + ethane hydrates were found to vary significantly with pressure, the composition, and the structure of hydrate. The prediction and experimental would likely agree if this variation in the enthalpy of dissociation was taken in to account.
In doing the plug dissociation studies at high methane mole fraction a discontinuity was observed in the gas evolution rate and X-ray diffraction indicated the possibility of the presence of both sI and sII hydrate structures. A detailed analysis by step-wise modelling utilising the hydrate prediction package CSMGem showed that preferential enclathration could occur. This conclusion was supported by experiment.
Salts such as tetraisopentylammonium fluoride form semi-clathrate hydrates with melting points higher than 30 ℃ and vacant cavities that can store cages such as methane and hydrogen. The stability of this semi-clathrate hydrate with methane was studied and the dissociation phase boundary was found to be at temperatures of about (25 to 30) K higher than that of methane hydrate at the same pressure.
13
Colbow, Kevin Michael. "Lithium intercalation in titanium based oxides and sulfides." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27860.
Анотація:
The Li-Ti-S ternary system was investigated. The elements and/or compounds, such as lithium sulfide, titanium disulfide and titanium trisulfide, were combined at high temperature (typically 500-900°C). The synthesized compounds containing one or more phases were structurally characterized using x-ray powder diffraction. When Lix TiS₂, (0 ≤ x ≤ 1) was synthesized at elevated temperature, a new polytype, 3R-LixTiS₂, was found for some values of x. The regions of stability of the 3R polytype and the well known 1T polytype are presented. Lithium can be intercalated or de-intercalated from both polytypes at room temperature. Ambient temperature Li/3R-LixTiS₂ cells have higher average voltages than Li/1T-Li TiS₂, cells.
The lithium spinel oxides are another class of
materials receiving attention as cathode materials in
lithium secondary batteries. LiTi₂0₄ is metallic, has the
cubic spinel structure and reacts with one further lithium
atom to form Li₂Ti₂0₄. The related spinel Li₄/₃Ti₅/₃⁰₄͵
which is electrically insulating, also reacts reversibly
with one lithium atom. Both Li₂Ti₂0₄ and Li₄/₃Ti₅/₃⁰₄͵
cells cycle reversibly, but have subtle differences in their
voltage profiles. The difference in cell behaviour was
interpreted based on the band structure of Li₁˖xTi₂₋x⁰₄.
The mixed spinels LiMnyTi₂₋y⁰₄ (0 ≤ y ≤ 2) were also investigated. These compounds were synthesized at high temperature but their performance as cathodes in lithium batteries was not encouraging.Science, Faculty of
Physics and Astronomy, Department of
Graduate
14
Suckling, Adrian Philip. "A study of secondary bonding effects in Werner clathrates." Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/21939.
Анотація:
The crystal structures of Ni(NCS)₂(4-ViPy)₂.nG where nG = 2CH₂Cl₂ (I), 2CCl₄ (II), 1.8CH₂I₂ (III) and CHI₃ (IV), as well as the crystal structure of [Ni(NCS)₂(4-ViPy)₄]. [Ni(NCS)₂(4-ViPy)₃(thf)].2CHI₃ (V) have been elucidated. The diiodomethane guest molecules in STRUCTURE III were severely disordered at room temperature and so this structure was solved at -40°C. The dichloromethane clathrate is isomorphous with the chloroform clathrate of the same host, and both these clathrates have a similar packing to the carbon tetrachloride clathrate. There is significant secondary bonding between the sulphur (donor) of the isothiocyanate ligand of the host and the iodines (acceptor) of the halogenated guest molecules in compounds III, IV and V. The iodoform clathrates, compounds IV and V, also show strong similarities in their packings. Particular attention has been paid to the shape and size of the cavities in which the guest molecules find themselves, in order to gain a better understanding of the nature of these clathrates. This has also shed some light on the probable cause of the disordered diiodomethane molecules in STRUCTURE III. Packing densities and volume comparisons of the [Ni(NCS)₂(4-ViPy)₂] clathrates have been carried out. Solid - state U.V/visible spectroscopy was used to obtain information on the host conformation, and thermal analysis (thermogravimatry and differential thermal analysis) was used to obtain insight into the host - guest interactions of these clathrates.
15
West, Lee Charles. "A study of bibracchial lariat ether complexes and linked cyclodextrin dimer complexes." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phw5182.pdf.
Анотація:
Includes errata attached to first leaf. Includes bibliographical references. The complexation of a range of monovalent and divalent metal ions by the bibracchial lariat ethers has been investigated. Also investigates the complexation of metal ions and the anionic azo dye Brilliant Yellow by the diazacrown linked cyclodextrin dimers.
16
Nohako, Kanyisa L. "Organic clathrates : structure and reactivity." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/740.
Анотація:
Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2009The host compound 9-(4-methoxyphenyl)-9H-xanthen-9-01 (AI) forms inclusion compounds with the solid guests l -naphthylamine (NAPH), 8-hydroxyquinoline (HQ). acridine (ACRI), 1,4 - diazabicyclo[2.2.2]octane (DABCO) and a liquid guest benzaldehyde (BENZAL). All four structures AI·YzNAPH, AI· Y,HQ AI·ACRI and AI ·Y,DABCO were successfully solved in the triclinic space group P I . The structure of AI·Y,BENZAL was successfully solved in the monocl inic space group P2dn . Similar packin g motifs arise for the NAPH and HQ inclusion compounds where the main interaction is of the fonm (Host)-OH····O-(Host). Both the DABCO and the ACRI guests hydrogen bond to the host molecule. The host: guest ratios for A I·ACRI. AI· Y,NAPH. A I· Y,DABCO and A I· YzHQ were found using nuclear magnetic resonance (NMR) spectroscopy. The host:guest ratio for AI·YzBENZAL was found using thenmogravimetric analysis. Enthalpy changes of the inclusion compounds were monitored using differential scanning calorimetry (DSC). Kinetics of desolvation for AI·Y,BENZAL were conducted using a non - isothenmal method where we have obtained an activation energy range of 74 k J morl - 86 k J mor' . The solid - solid reaction kinetics for A I·Y,NAPH, A I· Y,HQ, AI·ACRI and AI ·Y,DABCO were determined at room temperature using powder X-ray diffraction (PXRD).
17
Dube, Paul A. "Properties of magnetic transition metal-bromide graphite intercalation compounds /." *McMaster only, 2002.
18
Kim, Jung-Hwan. "Crystal structure and thermoelectric properties of Ba-Ge based type-3 clathrate compounds." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136270.
19
Schiller, Robert Lindsay. "Kinetic and equilibrium studies of some dye-cyclodextrin inclusion complexes /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phs334.pdf.
20
Brereton, Ian Malcolm. "A multinuclear NMR study of inclusion processes /." Title page, contents and introduction only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phb841.pdf.
21
Donnelly, Mary-Ellen. "Neutron diffraction of hydrogen inclusion compounds under pressure." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/31471.
Анотація:
When ice is compressed alongside a gas, crystalline 'host - guest' inclusion compounds known as gas clathrate hydrates form. These compounds are of interest not only for their environmental and possible technological impact as gas storage and separation materials, but also for their ability to probe networks not readily adopted by the pure `host' water molecules, and to study the interactions between water and gas molecules. Despite the pressure dependent crystal structures being fully determined for a large variety of `guest' gas species there is still relatively little known about the crystal structures in small guest gas systems such as H2 hydrate. The majority of structural studies have been done with x-ray diffraction and report a number of conflicting structures or hydrogen contents for the four known stable phases (sII, C0, C1 and C2). As this is a very hydrogen rich system the most ideal method to study the structure is neutron diffraction, which is able to fully determine the location of the hydrogen atoms within the structure and would allow a direct measurement of any hydrogen ordering within the host structure and the H2 content. In this work the phase diagram of the deuterated analogue of the H2-H2O system is explored at low pressures (below 0.3 GPa) with neutron diffraction. In the pressure/temperature region where the sII phase is known to be stable, two metastable phases were observed between the formation of sII from ice Ih and that this transition sequence occurred in line with Ostwald's Rule of Stages. One of these metastable phases was the C0 phase known to be stable in the H2-H2O system above 0.5 GPa, and the other is a new structure not previously observed in this system and is dubbed in this work as C-1 . Prior to this work the C0 phase has been reported with various structures that were determined with x-ray diffraction, and here the crystal structure and H2 content at low pressure are determined with neutron diffraction. The C0 phase was found to form a similar host structure to those of the previous studies with spiral guest sites but is best described with highly mobile H2 guests and a higher symmetry space group which make it the same structure as the spiral hydrate structure (s-Sp) recently observed in the CO2 hydrate system. In addition to this structure being determined at pressure a sample of C0 was also recovered to ambient pressure at low temperature and its structure/H2 content is presented as it was warmed to decomposition. The crystal structure of the C-1 phase was determined to be similar to ice Ih and a sample was recovered to ambient pressure to study its decomposition behaviour. Evidence for a similar structure in the helium hydrate system at low pressure is also reported here. This work was then extended to higher pressures with the recent developments of a hydrogen-compatible gas loader and large-volume diamond anvil cells. Several test experiments on gas-loaded Paris-Edinburgh presses are described on systems that are similar to hydrogen-water like urea-hydrogen and neon-water. And a further preliminary high pressure study on the deuterated analogue of the H2- H2O system in a diamond anvil cell between 3.6 and 28 GPa shows decomposition behaviour as pressure was increased.
22
Schultz, Peter Kasimir. "Structural relationships in layer silicates and their intercalates /." Title page, contents and summary only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09phs387.pdf.
23
Griffiths, Kieran. "Catalytic and topological aspects of Schiff base supported 3d-4f polynuclear coordination complexes." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/75278/.
Анотація:
The work presented in this thesis deals with the employment of Schiff base ligands used to synthesise novel 3d-4f polynuclear coordination clusters (PCCs) and the investigation into their potential magnetic, luminescent and catalytic properties. Chapter one provides a general introduction to the chemistry described in the thesis. It includes a general overview of 3d-4f PCC chemistry and the applications of these materials and previous synthetic strategies for the preparation of Schiff base PCCs. A rationale is presented for the ligands employed in the thesis and a synthetic strategy is devised for the synthesis of specific materials. The initial chapters are focused on the synthesis of 3d-4f PCCs with novel core topologies and the study of their magnetic properties. Several novel series of 3d-4f PCCs are presented with unique core topologies which are previously unobserved in 3d-4f PCC chemistry. In addition, some of the presented PCCs display single-molecule magnet (SMM) properties or a significant magnetocaloric effect (MCE). Chapter five bridges synthetic aspects discussed in the previous chapters, with a synthetic study targeting 3d-4f PCCs with a defect dicubane core (2,3M4-1) and introduces the term “isoskeletal” to describe PCCs which possess the same topology or related organic structures with the same host framework but different guests. Chapters seven to nine are focused on the development of a well characterised isoskeletal family of 3d-4f PCCs with a defect dicubane core and the investigation of their potential catalytic properties in a range of organic reactions including Michael Addition, Friedel-Crafts alkylations and multicomponent reactions. Characterisation of the 3d-4f PCCs is emphasised and verifies the stability of the 2,3M4-1 core in solution. An attempt at understanding the catalytic system and mechanistic aspects is undertaken, which is not explored in previously reported 3d-4f PCC co-operative catalysis. Chapter ten provides an overall conclusion to the work presented in the thesis, whilst highlighting the contributions of this work to the reported literature.
24
Dong, Sunny Ronald. "The investigation of indium halides and graphite intercalation compounds using time-differential perturbed angular correlation gamma-ray spectrosocopy." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28375.
Анотація:
This thesis discusses in general terms the theory and application of time-differential perturbed angular correlation gamma-ray spectroscopy (TDPAC) to the study of solid state physics. The technique yields valuable information on the electric field gradients experienced by radionuclides which have been substituted for nonradioactive isotopes or inserted as impurities into various inorganic compounds. The indium halides are examined in a series of experiments. The first applications of this technique to the study of graphite intercalation compounds are discussed.Science, Faculty of
Physics and Astronomy, Department of
Graduate
25
Wang, Ying. "Enhanced Li-ion intercalation properties of vanadium oxides /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/10561.
26
Aydemir, Umut. "Preparation and Characterization of Clathrates in the Systems Ba – Ge, Ba – Ni – Ge, and Ba – Ni – Si." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-88886.
Анотація:
The main focus of this work is the preparation, chemical and structural characterization along with the investigation of physical properties of intermetallic clathrates. Starting from the history of clathrate research, classification of clathrate types, their structural properties and possible application areas are evaluated in chapter 2. The methodologies of sample preparation and materials characterization as well as quantum chemical calculations are discussed in chapter 3.
The complete characterization of Ba8Ge433 ( is a Schottky-symbol standing for vacancies),12-14 which is a parent compound for the variety of ternary variants, is the subject of chapter 4. Ba8Ge433 is a high temperature phase,12 which was prepared for the first time as single phase bulk material in this work.15, 16 In this way, the intrinsic transport properties could be investigated without influence of grain boundary and impurity effects. The transport behavior is analyzed at low and high temperatures and referred to the former results. In addition, crystal structure and vacancy ordering in terms of the reaction conditions are discussed. Chemical bonding in Ba8Ge433 is investigated by topological analysis of the electron localizability indicator and the electron density.
Chapter 5 deals with the preparation, phase analysis, crystal structure and physical properties of BaGe5, which constitutes a new clathrate type oP60.17, 18 So far, two clathrate types were known in the binary system Ba – Ge, namely the clathrate cP124 Ba6Ge25,19-21 and the clathrate-I Ba8Ge433. Originally, BaGe5 was detected by optical and scanning electron microscopy within the grains of Ba8Ge433.12 Once the preparation of phase-pure Ba8Ge433 was achieved, it became possible to make detailed investigations of its decomposition along with the formation of BaGe5. A detailed theoretical and experimental analysis on the relation between crystal structure and physical properties of BaGe5 is presented.
In chapter 6, a thorough structural characterization and the physical properties of clathrates in the system Ba – Ni – Ge is presented based on the subtle relation between the crystal structure containing vacancies and the thermoelectric properties. During the investigations in this system, a large single crystal was grown by Nguyen et al. 22, 23 from the melt with the composition Ba8Ni3.5Ge42.10.4. A systematic reinvestigation of the phase relations in this system was performed and the influence of different Ni content to the crystal structure and physical properties is evaluated.
The Si-based ternary clathrate with composition Ba8–δNixySi46–x–y is the subject of chapter 7. The phase relations and the homogeneity range are established. The crystal structure taking into account vacancies in the framework is discussed. Physical properties of bulk pieces are analyzed and the results are related to the sample composition. In addition, first-principles electronic structure calculations are carried out to assess variations in the electronic band structure, phase stability and chemical bonding.24
Chapter 8 reports on the intermetallic compound Ba3Si4,25, 26 which was encountered during the investigations on the Ba – Ni – Si phase diagram. The discussion covers issues related to preparation, crystal structure, phase diagram analysis, electrical and magnetic properties, NMR measurements, quantum mechanical calculations and oxidation to nanoporous silicon with gaseous HCl.
Besides my contributions to the NoE CMA, I studied under the Priority Program 1178 of Deutsche Forschungsgemeinschaft “Experimental electron density as the key for understanding chemical interactions” with the project of “Charge distribution changes by external electric fields: investigations of bond selective redistributions of valence electron densities”. Chapter 9 deals with the preparation of chalcopyrites ZnSiP2 and CuAlS2 for experimental charge density analysis. Both phases show semiconducting properties and have non-centrosymmetric structures with high space group symmetry as needed to investigate the structural changes induced by external electric field. In this chapter, I describe the preparation and the crystal structure analyses of ZnSiP2 and CuAlS2 including issues related to the data collection as well as the results of NMR investigation.
27
Bandara, Nilantha. "Guest intercalation into metal halide inorganic-organic layered perovskite hybrid solids and hydrothermal synthesis of tin oxide spheres." Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-10312008-212759.
28
Zhang, Yongcheng. "Part I. Natural fiber / thermoplastic composites Part II. Studies of organo-clay synthesis and clay intercalation by epoxy resins /." Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11032008-094748.
29
Tabner, Vivienne Amanda. "Spectroscopic studies of clathrates and inclusion compounds." Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280748.
30
Meier, Katrin. "Hochdruck–Hochtemperatur–Synthese und Charakterisierung tetrelreicher Seltenerdmetallverbindungen und Darstellung von Ba8Ga16±xGe30∓x mittels Spark–Plasma–Sinterverfahren." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105084.
Анотація:
In dieser Dissertation wird die Darstellung tetrelreicher Seltenerdmetall–Verbindungen in den Systemen SE:Tt (SE = La, Nd, Sm, Gd, Tb, Ho, Lu; Tt = Si, Ge) und die Charakterisierung ihrer Eigenschaften beschrieben. Diese Verbindungen, welche mittels der Hochdruck–Hochtemperatur–Methode dargestellt wurden, zeigen neuartige Verknüpfungsmuster in der Tetrel–Partialstruktur. Neben der Charakterisierung der Verbindungen hinsichtlich der thermischen Stabilität und der physikalischen Eigenschaften bei Normaldruck wurde bei den Germanium–reichen Seltenerdmetall–Verbindungen eine Untersuchung der Veränderungen der Kristallstruktur bei Variation des Drucks oder der Temperatur vorgenommen. Die dargestellten Seltenerdmetall–Trisilicide SESi3 (SE = Gd, Ho, Lu) kristallisieren tetragonal isotyp zu YbSi3. LuSi3 zeigt Supraleitung mit Tc = 7.0 K. In den Systemen Gd–Si und SE–Ge (SE = La, Nd, Sm, Gd, Tb) wurden die Verbindungen GdSi5 und SEGe5 (SE = La, Nd, Sm, Gd, Tb) synthetisiert. Sie kristallisieren orthorhombisch isotyp zu LaGe5. Durch in–situ Röntgenbeugungsexperimente bei erhöhten Temperaturen kann die Existenz metastabiler Germanium–ärmerer Verbindungen SE2Ge9 (SE = Nd, Sm) nachgewiesen werden. Es handelt sich um Defektvarianten der Verbindungen SEGe5 (SE = Nd, Sm). Die strukturelle Verwandtschaft zum Aristotyp SEGe5 wird anhand einer Gruppe–Untergruppe–Beziehung aufgezeigt. Eine alternative Synthesemethode zur Darstellung tetrelreicher Verbindungen mit Gerüststrukturen bei extremen Reaktionsbedingungen stellt das Spark–Plasma–Sinterverfahren (SPS) dar. Die Darstellung der Clathratphase Ba8Ga16±xGe30∓x (x = 0, 1) erfolgte mittels SPS aus den Precursoren BaGa2±x (x = 0, 0.125) und Germanium. Die Untersuchungen der thermoelektrischen Eigenschaften zeigen, dass durch Variation der nominellen Zusammensetzung sowohl n–leitende als auch p–leitende Eigenschaften erhalten werden könnenIn this thesis the synthesis of tetrel–rich rare–earth metal compounds in the systems RE:Tt (RE = La, Nd, Sm, Gd, Tb, Ho, Lu; Tt = Si, Ge) and the characterization of their properties is described. These compounds, synthesized by means of high–pressure high–temperature method, show new structural motifs in the tetrel partial structure. The compounds were characterized with respect to their thermal stability and their physical properties at ambient pressure. In addition, the changes in the crystal structure of the germanium-rich rare–earth metal compounds by variation of pressure or temperature were investigated. The synthesized rare–earth trisilicides SESi3 (SE = Gd, Ho, Lu) crystallize tetragonal, isotypic to YbSi3. LuSi3 is a superconductor with Tc = 7.0 K. In the systems Gd–Si and SE–Ge (SE = La, Nd, Sm, Gd, Tb) the compounds GdSi5 and SEGe5 (SE = La, Nd, Sm, Gd, Tb) were synthesized. They crystallize orthorhombic isotypic to LaGe5. Using in-situ high–temperature X-ray experiments the metastable germanium-poorer compounds SE2Ge9 (SE = Nd, Sm) could be observed. These compounds are defect variants of the pentagermanides SEGe5 (SE = Nd, Sm). The structural relationship to the aristotype SEGe5 is given via a group-subgroup relation. An alternative synthesis route for the preparation of tetrel–rich compounds with framework structures at extreme reaction conditions is the spark plasma sintering method (SPS). The clathrate phase Ba8Ga16±xGe30∓x (x = 0, 1) was synthesized from the precursors BaGa2±x (x = 0, 0.125) and germanium by means of SPS. The investigation of the thermoelectric properties shows, that through variation of the nominal composition both n-type and p-type conduction properties can be obtained
31
Veiga, Larissa Sayuri Ishibe 1987. "Estudo de composto intermetálico clatrato Eu8Ga16Ge30 por difração magnética de raios-X." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277495.
Анотація:
Orientador: Carlos Manuel Giles Antunez de MayoloDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-08-18T09:44:07Z (GMT). No. of bitstreams: 1 Veiga_LarissaSayuriIshibe_M.pdf: 17048771 bytes, checksum: 679326ce3ab87d18e691e2a4c2789f17 (MD5) Previous issue date: 2011
Resumo: Neste trabalho estudamos o comportamento magnético do composto Eu8Ga16Ge30, o único clatrato conhecido atualmente cujas posições hóspedes são completamente preenchidas por um elemento terra-rara. Este composto cristaliza-se em uma estrutura cúbica (grupo espacial Pm_3n), apresentando duas diferentes gaiolas formadas pelos átomos Ga-Ge (uma gaiola menor formada por 20 átomos e uma gaiola maior, formada por 24 átomos) que englobam em seu interior íons divalentes Eu+2. Os momentos magnéticos desses íons ordenam-se ferromagneticamente abaixo de TC = 36 K através da interação RKKY. O objetivo deste trabalho foi investigar o comportamento magnético local dos sítios cristalográficos ocupados pelos íons de Eu, que no interior das gaiolas maiores, situam-se em posições fora do centro destas, contidas em planos perpendiculares às faces da célula unitária cúbica. Nesta dissertação descrevemos a síntese do composto Eu8Ga16Ge30 pelo método do fluxo metálico, a caracterização da amostra através da difração de raios X de alta resolução (verificação da qualidade cristalina) e da difração de pó de raios X (determinação do parâmetro de rede). Medidas de resistividade elétrica em função da temperatura mostraram a existência de saltos relacionados ao aumento da resistividade, na temperatura de transição magnética (TC) e em T* = 24 K. O mesmo comportamento foi verificado na literatura que indica que a anomalia encontrada em T* possui origem magnética. As propriedades magnéticas foram estudadas através de medidas de grandezas macroscópicas, como susceptibilidade magnética e magnetização em função do campo magnético aplicado. O comportamento magnético local do composto foi estudado através da técnica de difração magnética ressonante com seletividade aos sítios cristalográficos ocupados pelos átomos de Eu. Esta última técnica foi capaz de fornecer informações locais sobre o magnetismo dos átomos de Eu localizados nos sítios 2a e 24k através do estudo das histereses magnéticas obtidas na condição de difração em diferentes temperaturas. Foi observado que o comportamento magnético dos sítios cristalográficos 2a e 24k são diferentes para a temperatura de 8 K, no entanto, nenhuma diferença significativa foi encontrada para as histereses dos dois sítos em T = 30 K. Verificamos que a histerese magnética do sítio 24k em 8 K é formada por várias contribuições indicando a existência de uma estrutura magnética em que os momentos magnéticos situados neste sítio encontram-se dispostos ao longo de três direções perpendiculares entre sí. Verificamos também histereses magnéticas menos estruturadas em T = 30 K que podem estar relacionadas à presença de uma estrutura magnética na qual todos os momentos magnéticos estão orientados ao longo de uma única direção (eixo de fácil magnetização, na direção [001]). No entanto, o mecanismo que descreve o comportamento magnético deste composto (reorientação de spins ou duas temperaturas de ordenamento magnético) ainda não foi totalmente elucidado
Abstract: In this work we studied the magnetic behavior of Eu8Ga16Ge30 clathrate compound, the only clathrate known so far where the guest positions are fully occupied by a rare-earth element. This compound crystallizes in a cubic unit cell (space group Pm_3n) and presents two types of cages formed by Ga-Ge atoms (a smaller cage formed by 20 atoms and a larger cage, formed by 24 atoms) inside which Eu+2 guest ions reside. The magnetic moments of these ions order ferromagnetically below TC _ 36 K through RKKY interaction. The aim of this thesis was the investigation of the local magnetic properties of the crystallographic sites occupied by Eu ions, which inside of the larger cages, are located in four off-center positions contained in planes perpendicular to the faces of the cubic unit cell. In this work we describe the synthesis process of Eu8Ga16Ge30 compound. Eu8Ga16Ge30 single crystal was grown from metallic flux method with excess of Ga. We also describe the structural characterization of the samples by high resolution x-ray diffraction and x-ray powder diffraction. Electrical resistivity measurements were performed and showed anomalies not only at TC but also at T* _ 24 K. The same behavior was observed in the literature which indicates that the anomaly found in T* has a magnetic nature. The magnetic properties were studied by macroscopic measurements such as magnetic susceptibility and magnetization versus applied magnetic field. The local magnetic behavior of the compound was probed by dichroic resonant diffraction of circularly polarized x rays. This technique was used to measure site-specific magnetism of the Eu8Ga16Ge30 compound. It was able to provide information about the magnetism of the crystallographic sites 2a and 24k occupied by Eu ions through the study of magnetic hysteresis obtained in the diffraction condition at different temperatures. It was observed that the magnetic behavior of the 2a and 24k crystallographic sites are different for the temperature of 8 K. However, no difference was found for the hysteresis of the two sites on T = 30 K. The results suggest that the magnetic hysteresis of the 24k site at 8 K is formed by several contributions indicating the existence of a magnetic structure where the magnetic moments located on this site are arranged along three mutually perpendicular directions. We also found less structured magnetic hysteresis at T = 30 K which may be related to the presence of a magnetic structure in which all magnetic moments are oriented along a single direction (easy axis of magnetization along [001]). However, the mechanism that describes the magnetic behavior of this compound (spin reorientation or two temperatures of magnetic ordering) has not been fully elucidated
Mestrado
Física Atômica e Molecular
Mestra em Física
32
Ocampo, Juan. "Etude des phénomènes d'interface dans la glace : adsorption, croissance des clathrates et désordre protonique : [thèse en partie soutenue sur un ensemble de travaux]." Grenoble 1, 1988. http://www.theses.fr/1988GRE10087.
Анотація:
Etude depuis l'etat amorphe a 77 k jusqu'a l'etat hexagonal pres du point de fusion de l'evolution structurale et dynamique de la surface de la glace en contact ou non avec des gaz (he, kr, ar, n::(2), co::(2), nc::(4)h::(10)) ou des solides (sio::(2), pvc, h::(2)so::(4)). Approche thermodynamique (adsorption de gaz), cinetique (frittage et croissance de clathrates) et spectroscopique (rmn des protons). Mecanisme de reconstruction de la surface depuis l'adsorption jusqu'a la clathration, en tenant compte des coefficients de diffusion et des energies d'activation mesurees. Existence d'une couche quasi-liquide sur la surface de la glace pour des temperatures superieures a 238 k, et dans le cas des interfaces avec d'autres corps solides
33
"Synthesis, clathrate inclusion properties and racemization studies of Benzo-fused tetraphenylenes." Chinese University of Hong Kong, 1988. http://library.cuhk.edu.hk/record=b5885948.
34
Kawamura, Taro, Michika Ohtake, Yoshitaka Yamamoto, and Satoru Higuchi. "HYDROGEN ABSORPTION BEHAVIOR OF ORGANIC-COMPOUND CLATHRATE HYDRATES." 2008. http://hdl.handle.net/2429/1400.
Анотація:
The hydrogen absorption behavior of organic-compound clathrate hydrates was investigated using five kinds of organic compounds as well as tetrahydrofuran (THF). These hydrates were pressurized by hydrogen, and Raman analysis, the determination of the amount of hydrogen and calorimetric measurement were carried out. The Raman results show that the samples investigated in this work formed binary clathrate hydrate of hydrogen and each organic compound. The organic-compound clathrate hydrates presented similar performances to that of THF clathrate hydrate regarding hydrogen absorption and heat of dissociation. These results suggested that the organic compounds investigated in this work may become alternatives to THF.
35
Kaltzoglou, Andreas [Verfasser]. "Synthesis, characterization and physical properties of semiconducting clathrate compounds / Andreas Kaltzoglou." 2009. http://d-nb.info/994942303/34.
36
Lindsell, Graeme Alexander. "Structure and dynamics of graphite intercalation compounds." Phd thesis, 1998. http://hdl.handle.net/1885/144670.
37
"New host lattices containing monocyclic oxocarbon anions, urea/thiourea and water molecules." 1998. http://library.cuhk.edu.hk/record=b5889665.
Анотація:
by Chi-Keung Lam.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 100-103).
Abstract also in Chinese.
Acknowledgments --- p.i
Abstract --- p.ii
摘要 --- p.iii
Table of contents --- p.iv
Index of compounds --- p.v
List of tables --- p.vi
List of figures --- p.vii
Chapter Chapter 1. --- Introduction
Chapter 1.1 --- Some aspects of urea/thiourea inclusion chemistry --- p.1
Chapter 1.2 --- General chemistry of monocyclic oxocarbons --- p.5
Chapter 1.2.1 --- Synthesis of monocyclic oxocarbons --- p.5
Chapter 1.2.2 --- Aromaticity of monocyclic oxocarbon anions --- p.20
Chapter 1.2.3 --- Reactions of monocyclic oxocarbons --- p.25
Chapter 1.3 --- Aim of the present research --- p.31
Chapter Chapter 2. --- Description of crystal structures
Chapter 2.1 --- Urea-anion inclusion compounds --- p.32
Chapter 2.1.1 --- Bis(tetra-n-propylammonium) squarate-urea-water (1/ 6/2) --- p.32
Chapter 2.1.2 --- Tetra-n-butylammonium hydrogen squarate-urea-water (1/1/1) --- p.38
Chapter 2.1.3 --- Bis(tetraethylammonium) squarate-tetraethylammonium hydrogen carbonate- urea-water (1/2/4/6) --- p.42
Chapter 2.1.4 --- Bis(tetra-n-propylammonium) croconate-urea-water (1/5/2) --- p.47
Chapter 2.2 --- Thiourea-anion inclusion compounds --- p.53
Chapter 2.2.1 --- Bis(tetraethylammonium) squarate-thiourea-water (1/4/ 2) --- p.53
Chapter 2.2.2 --- Bis(tetraethylammonium) squarate-thiourea (1/6) --- p.59
Chapter 2.2.3 --- Bis(tetra-n-propylammonium) squarate-thiourea-water (1/ 4/2) --- p.66
Chapter Chapter 3. --- Summary and discussion
Chapter 3.1 --- Urea/thiourea monocyclic oxocarbon anions inclusion compounds --- p.71
Chapter 3.2 --- Structural features and topological correlations of the host lattices --- p.72
Chapter 3.3 --- Hydrogen bonding and linkage modes of urea and thiourea molecules --- p.87
Chapter Chapter 4. --- Experimental
Chapter 4.1 --- Preparation of crystals --- p.91
Chapter 4.2 --- X-ray Crystallography --- p.93
References --- p.100
Appendix Atomic coordinates and thermal parameters of the new inclusion compounds --- p.104
38
Clarke, Ronald James 1947. "Kinetic and equilibrium studies of cyclodextrin-azo dye inclusion complexes / Ronald James Clarke." 1985. http://hdl.handle.net/2440/19775.
Анотація:
Offprints of two author's journal articles inserted at end of the v.Bibliography: leaves 10-12
216 leaves : ill ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1985
39
Clarke, Ronald James 1947. "Kinetic and equilibrium studies of cyclodextrin-azo dye inclusion complexes / Ronald James Clarke." Thesis, 1985. http://hdl.handle.net/2440/19775.
Анотація:
Offprints of two author's journal articles inserted at end of the v.Bibliography: leaves 10-12
216 leaves : ill ; 30 cm.
Thesis (Ph.D.) -- University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1985
40
"New Inclusion compounds of urea/thiourea/selenourea with peralkylated ammonium salts." Chinese University of Hong Kong, 1995. http://library.cuhk.edu.hk/record=b5888849.
Анотація:
by Qi Li.Thesis (Ph.D.)--Chinese University of Hong Kong, 1996.
Includes bibliographical references (leaves 192-199).
Acknowledgment --- p.i
Abstract --- p.ii
Table of Contents --- p.iii
Index of Componds --- p.iv
List of Tables --- p.v
List of Figures --- p.vi
Chapter 1. --- Introduction --- p.1
Chapter 1.1. --- General Survey of Inclusion Chemistry --- p.1
Chapter 1.2. --- The Importance of Hydrogen Bonds --- p.5
Chapter 1.3. --- "Classical Inclusion Compounds of Urea, Thiourea and Selenourea" --- p.8
Chapter 1.4. --- Research Strategy --- p.12
Chapter 2. --- Description of Crystal Structures --- p.16
Chapter 2.1. --- Urea-Anion Inclusion Compounds --- p.16
Chapter 2.1.1. --- Halide complexes --- p.18
Chapter 2.1.2. --- Bicarbonate complexes --- p.30
Chapter 2.1.3. --- Allophanate complexes --- p.36
Chapter 2.1.4. --- Borate and pentaborate complexes --- p.44
Chapter 2.1.5. --- Complex featuring both host-host and host-guest hydrogen bonding --- p.60
Chapter 2.1.6. --- Tetraethylammonium and phosphonium chloride complexes --- p.65
Chapter 2.2. --- Thiourea-Anion Inclusion Compounds --- p.71
Chapter 2.2.1. --- Halide Complexes --- p.73
Chapter 2.2.2. --- Bicarbonate Complexes --- p.76
Chapter 2.2.3. --- Nitrate Complexes --- p.87
Chapter 2.2.4. --- Formate Complexes --- p.101
Chapter 2.2.5. --- Acetate Complexes --- p.113
Chapter 2.2.6. --- Oxalate and Fumarate Complexes --- p.127
Chapter 2.2.7. --- Unsymmetrical quaternary ammonium ions as guests --- p.138
Chapter 2.3. --- Selenourea-Anion Inclusion Compounds --- p.152
Chapter 3. --- Summary and Discussion --- p.161
Chapter 3.1. --- Structural Features and Relationships --- p.161
Chapter 3.2. --- Hydrogen Bonding in Urea/Thiourea/Selenourea-Anion Inclusion Compounds --- p.164
Chapter 3.3. --- Linkage Modes of Urea and Thiourea Molecules --- p.168
Chapter 3.4. --- Comolecular Aggregates of Urea and Other Host Components --- p.173
Chapter 3.5. --- Comolecular Aggregates of Thiourea and Other Host Components --- p.175
Chapter 4. --- Experimental --- p.177
Chapter 4.1. --- Preparation --- p.177
Chapter 4.2. --- Crystallography --- p.182
Chapter 5. --- References --- p.192
Appendix A: Tables of Atomic coordinates and thermal parameters --- p.200
Appendix B: Publication Based on Results Reported in This Thesis --- p.243
41
Guan-ShiueHuang and 黃冠學. "Study of thermoelectric properties in the clathrate compounds Ba8Ga16-xSi30+x and Ba8-yGa16S30." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/18809735336603918772.
Анотація:
碩士國立成功大學
物理學系碩博士班
101
Clathrate compounds are expected to have good thermoelectric property; because of their structure. The guest atoms are included in the host cages. Because of weak interaction between the guest and framework atoms, rattling motion can make the lattice thermal conductivity lower, so it may have higher figure-of-merit, ZT. This paper is for Ba8Ga16-xSi30+x (x= -1,0,1) and Ba8-yGa16S30 (y=0,1,2) clathrate compounds. They are prepared by arc-melting and characterized for their structure by x-ray diffraction, electrical resistivity, Seebeck coefficient and thermal conductivity measurements. It is found that the Ba8Ga16Si30 has the biggest ZT=0.06 in room temperature (T=300 K). We estimated that Ba8Ga17Si29 has ZT=1.01 at T=900 K bigger than Ba8Ga16Si30 whose ZT is 0.89 at the same temperature, because Ba8Ga17Si29 has a higher Seebeck coefficient and a lower electrical resistivity.
42
Di, Profio Pietro, Simone Arca, Raimondo Germani, and Gianfranco Savelli. "NOVEL NANOTECHNOLOGY FOR EFFICIENT PRODUCTION OF BINARY CLATHRATE HYDRATES OF HYDROGEN AND OTHER COMPOUNDS." 2008. http://hdl.handle.net/2429/2296.
Анотація:
The efficient production of hydrogen hydrates is a major goal in the attempt to exploit those materials as an alternative means for storing hydrogen. Up to now, a few processes have been reported in the literature which yield less than 1 wt% of hydrogen stored into clathrate hydrate or semi-clathrate forms. One main obstacle to the entrapment of sensible amounts of hydrogen (i.e., up to 4 wt% ) into a clathrate matrix appears to be of a kinetic origin, in that the mass transfer of hydrogen gas into clathrate structures is drastically limited by the (relatively) macroscopic scale of the gas-liquid or gas-ice interfaces involved.
In this communication, we present a novel process for an enhanced production of binary hydrates of hydrogen and other hydrate-forming gases, which is characterized by the use of nanotechnology for reducing the size of hydrate particles down to a few nanometers. This drastic reduction of particle size, down to three orders of magnitude smaller than that obtainable by macroscopic methods, allows to reduce the kinetic hindrance to hydrate formation. This process has a huge potential for increasing the amount of hydrogen stored, as it has provided ca. 1 wt% of hydrogen, with THF as a co-former. The present process also allows to use several non-water soluble coformers; first reports of hydrogen/cyclopentane and hydrogen/tetrahydrothiophene hydrates are presented.
43
West, Lee Charles. "A study of bibracchial lariat ether complexes and linked cyclodextrin dimer complexes / by Lee Charles West." Thesis, 2000. http://hdl.handle.net/2440/19852.
Анотація:
Includes errata attached to first leaf.Includes bibliographical references.
vi, 158 leaves : ill. (some col.) ; 30 cm.
The complexation of a range of monovalent and divalent metal ions by the bibracchial lariat ethers has been investigated. Also investigates the complexation of metal ions and the anionic azo dye Brilliant Yellow by the diazacrown linked cyclodextrin dimers.
Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 2000
44
Ashmore, Jason Chemistry Faculty of Science UNSW. "The synthesis and inclusion chemistry of diheteroaromatic compounds." 2007. http://handle.unsw.edu.au/1959.4/40826.
Анотація:
Diquinoline molecules have been shown previously to have interesting inclusion properties. Of the nine new, targeted molecules produced for this work, seven formed inclusion compounds, and their solid-state structures are discussed herein. Chapter 2 shows the effect that substituting a hydrogen atom with a chlorine atom has on the inclusion properties. This comes about because of the additional intermolecular attractions that are now possible, and a wider range of guest molecules is included as a result. A new homochiral aromatic 'swivel offset face-face (OFF)' interaction is observed. Chapters 3 and 4 deal with the effect of adding extra aromatic planes to the target molecules, two or four planes, respectively. Each of these host molecules formed dimeric host-host units that are extremely similar across all crystal structures. These dimers mainly employed aromatic edgeface (EF) interactions. Chapter 5 looks at the effect of combining the modifications described in Chapters 2-4, namely additional aromatic surfaces and atom substitution. The resulting host molecule specifically includes polyhalomethane guests. In addition, this host molecule formed two concomitant pseudo-dimorph compounds with chloroform-d. The diquinoline host molecule presented in Chapter 6 incorporated an isomeric central linker ring to the other compounds. Although only a single crystal structure could be obtained, 1H NMR spectroscopy experiments show other small aromatics may be included. The effect of electron donating chemical substituents was examined in Chapter 7. These compounds were found to be quite insoluble, and did not produce crystals suitable for X-ray analysis. The host molecules in Chapter 8 contain electron withdrawing nitro groups. The two isomeric compounds that act as inclusion hosts show quite different properties. One of these hosts forms a series of inclusion compounds with water, in which the site occupancy of the guest can range from 0-100% without change to the overall structure. All the X-ray structures described have been analysed in crystal engineering terms, and their supramolecular interactions described in detail.
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"Designed construction of hydrogen-bonded host lattices with urea/thiourea, guanidinium and selected anions." Thesis, 2009. http://library.cuhk.edu.hk/record=b6074746.
Анотація:
Investigation on a series of hydrogen-bonded networks constructed with N-heteroaryl acids is described in Section 3.4. In this section, we focused on the connection modes within the heteroaryl dimer. The study of co-crystals and inclusion compounds based on 2-thiobarbituric acid (TBA) or trithiocyanuric acid (TCA) indicated that the dimer of TBA is present in all three crystals in the forms of ribbon, tetramer or separated dimer. In the case of 5-nitrobarbiturate, its dimer occurs in two ammonium salts and in three of its four thiourea complexes, but is absent in all three urea complexes.Self-assembly of two-dimensional hydrogen-bonded honeycomb grids exhibiting the rosette motif has been conducted with the guanidinium cation and various anions as the building blocks, tetraalkylammonium ions of suitable bulk being employed as interlayer templates. It is noteworthy that the rosette layer constructed from three different trigonal-planar molecular components has been achieved. In addition, deviating from conventional topological design, the generation of new rosette layers, albeit highly distorted, has also been accomplished with 1,2-dithiosquarate and the dianionic form of 1,1'-biphenyl-2,2',6,6'-tetracarboxylate that do not conform to C3-symmetry. Although threefold molecular symmetry is regarded as a sacrosanct requirement for molecular building blocks in the construction of hydrogen-bonded rosette motif, this study shows that rosette motifs can be generated even if one of the building blocks does not have inherent threefold symmetry.
Study of compounds containing the deprotonated forms of Kemp's triacid (H3KTA) has revealed the chair or twist-boat conformation in six crystal structures. X-ray structural analysis showed that [C(NH2) 3+] · [C6H6(CH3) 3(COOH)2(COO-)] (2.2.2) exhibits a corrugated layer structure which mimics the rosette motif constructed from the guanidinium ion and the hydrogen carbonate dimer. The tricarboxylate form of Kemp's triacid KTA3- in 3[C(NH2) 3+] · [C6H6(CH3) 3(COO-)3] (2.2.4) registers a record number of eighteen acceptor hydrogen bonds involving the convergent N--H donor sites from nine guanidinium ions. The crystal structure of 3[(C2H5)4N+] · 20[C(NH 2)3+] · 11[C6H6(CH 3)3(COOH) (COO-)2] · [C6H6(CH3)3(COOH)2(COO -)]·17H2O (2.2.3) features a hydrogen-bonded aggregate with a centrosymmetric pseudo-octahedral arrangement of H2KTA- anions surrounding an inner core composed of eight guanidinium ions. The unusual twist-boat conformation of KTA3- is found in [(CH3)4N +] · 2[C(NH2)3+] · [C6H6(CH3)3(COO- )3] · 2H2O (2.2.6), which is stabilized by the co-existence of guanidinium and tetramethylammonium cations.
Systematic investigation on hydrogen-bonded supramolecular assembly using aromatic carboxylic acids bearing linear or bent skeletons with urea/guanidinium resulted in the formation of mainly R228 and R126 synthon motifs. In addition, isostructures were also constructed by varying the length of the linker between two carboxylate groups, as in naphthalene-2,6-dicarboxylate (2.3.2) and biphenyl dicarboxylate (2.3.3).
This thesis reports a systematic investigation on the generation of new inclusion compounds by the combined use of urea/thiourea, guanidinium ion and various organic anions as building blocks of hydrogen-bonded host lattices and selected quaternary ammonium ion as the enclosed guests.
Various acids bearing specific functional groups have been explored as structure building components, including boric acid, Kemp's triacid, heterocyclic (thio)urea derivatives, aryl and N-heteroaryl carboxylic acids and (dithio)squaric acid. All the co-crystals and inclusion compounds built of molecular components in the afore-mentioned categories have been characterized by single-crystal X-ray analysis. As a result, the complexes exhibit a rich variety of inclusion topologies, such as networks containing isolated cages, open channels, intersecting tunnels, double-layer systems, and sandwich-like as well as wave-like layer structures.
Han, Jie.
Adviser: Thomas C. W. Mak.
Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0337.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 204-218).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.
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Schiller, Robert Lindsay. "Kinetic and equilibrium studies of some dye-cyclodextrin inclusion complexes / Robert Lindsay Schiller." Thesis, 1986. http://hdl.handle.net/2440/20598.
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Meier, Katrin. "Hochdruck–Hochtemperatur–Synthese und Charakterisierung tetrelreicher Seltenerdmetallverbindungen und Darstellung von Ba8Ga16±xGe30∓x mittels Spark–Plasma–Sinterverfahren." Doctoral thesis, 2012. https://tud.qucosa.de/id/qucosa%3A26568.
Анотація:
In dieser Dissertation wird die Darstellung tetrelreicher Seltenerdmetall–Verbindungen in den Systemen SE:Tt (SE = La, Nd, Sm, Gd, Tb, Ho, Lu; Tt = Si, Ge) und die Charakterisierung ihrer Eigenschaften beschrieben. Diese Verbindungen, welche mittels der Hochdruck–Hochtemperatur–Methode dargestellt wurden, zeigen neuartige Verknüpfungsmuster in der Tetrel–Partialstruktur. Neben der Charakterisierung der Verbindungen hinsichtlich der thermischen Stabilität und der physikalischen Eigenschaften bei Normaldruck wurde bei den Germanium–reichen Seltenerdmetall–Verbindungen eine Untersuchung der Veränderungen der Kristallstruktur bei Variation des Drucks oder der Temperatur vorgenommen.
Die dargestellten Seltenerdmetall–Trisilicide SESi3 (SE = Gd, Ho, Lu) kristallisieren tetragonal isotyp zu YbSi3. LuSi3 zeigt Supraleitung mit Tc = 7.0 K. In den Systemen Gd–Si und SE–Ge (SE = La, Nd, Sm, Gd, Tb) wurden die Verbindungen GdSi5 und SEGe5 (SE = La, Nd, Sm, Gd, Tb) synthetisiert. Sie kristallisieren orthorhombisch isotyp zu LaGe5. Durch in–situ Röntgenbeugungsexperimente bei erhöhten Temperaturen kann die Existenz metastabiler Germanium–ärmerer Verbindungen SE2Ge9 (SE = Nd, Sm) nachgewiesen werden. Es handelt sich um Defektvarianten der Verbindungen SEGe5 (SE = Nd, Sm). Die strukturelle Verwandtschaft zum Aristotyp SEGe5 wird anhand einer Gruppe–Untergruppe–Beziehung aufgezeigt.
Eine alternative Synthesemethode zur Darstellung tetrelreicher Verbindungen mit Gerüststrukturen bei extremen Reaktionsbedingungen stellt das Spark–Plasma–Sinterverfahren (SPS) dar. Die Darstellung der Clathratphase Ba8Ga16±xGe30∓x (x = 0, 1) erfolgte mittels SPS aus den Precursoren BaGa2±x (x = 0, 0.125) und Germanium. Die Untersuchungen der thermoelektrischen Eigenschaften zeigen, dass durch Variation der nominellen Zusammensetzung sowohl n–leitende als auch p–leitende Eigenschaften erhalten werden können.In this thesis the synthesis of tetrel–rich rare–earth metal compounds in the systems RE:Tt (RE = La, Nd, Sm, Gd, Tb, Ho, Lu; Tt = Si, Ge) and the characterization of their properties is described. These compounds, synthesized by means of high–pressure high–temperature method, show new structural motifs in the tetrel partial structure. The compounds were characterized with respect to their thermal stability and their physical properties at ambient pressure. In addition, the changes in the crystal structure of the germanium-rich rare–earth metal compounds by variation of pressure or temperature were investigated. The synthesized rare–earth trisilicides SESi3 (SE = Gd, Ho, Lu) crystallize tetragonal, isotypic to YbSi3. LuSi3 is a superconductor with Tc = 7.0 K. In the systems Gd–Si and SE–Ge (SE = La, Nd, Sm, Gd, Tb) the compounds GdSi5 and SEGe5 (SE = La, Nd, Sm, Gd, Tb) were synthesized. They crystallize orthorhombic isotypic to LaGe5. Using in-situ high–temperature X-ray experiments the metastable germanium-poorer compounds SE2Ge9 (SE = Nd, Sm) could be observed. These compounds are defect variants of the pentagermanides SEGe5 (SE = Nd, Sm). The structural relationship to the aristotype SEGe5 is given via a group-subgroup relation. An alternative synthesis route for the preparation of tetrel–rich compounds with framework structures at extreme reaction conditions is the spark plasma sintering method (SPS). The clathrate phase Ba8Ga16±xGe30∓x (x = 0, 1) was synthesized from the precursors BaGa2±x (x = 0, 0.125) and germanium by means of SPS. The investigation of the thermoelectric properties shows, that through variation of the nominal composition both n-type and p-type conduction properties can be obtained.