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

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.

Thesis: Elec. E., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1981 / Includes bibliographical references. / by Mansour Shayegan. / Elec. E. / Elec. E. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

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.

Thesis (MTech (Chemistry))-- Cape Peninsula University Technology, 2012 / The 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 A1ANI and A1MORPH were successfully solved in space group P21/c, whereas A13PIC was solved in 𝑃ī. Non-isothermal kinetics of desolvation were performed for A13PIC and A1MORPH. The packing of A13PIC and A1MORPH is characterized by (Host)(Guest) hydrogen bonds, whereas A1ANI 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 (A1NMA), C20H16O3 2C3H7NO (A12NMA) and 2C20H16O3 2C3H7NO (2A12NMA). The packing of A1NMA, A12NMA and 2A12NMA are characterized by (Host)-OHO-(Guest) and (Guest)-NHO-(Guest) hydrogen bonds, which gave hydrogen bonding patterns of 𝐶2 2(7), 𝐶3 3(11) and 𝐶4 2(11) respectively. The hydrate A1NMFH2O was successfully solved in the triclinic space group 𝑃ī. The A1NMFH2O 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 (A2MORPH), N-methylacetamide (A2NMA) and N-methylformamide (A2NMF), with host-guest ratios 1:1. The crystal structure of the apohost was solved in Pbca with Z=8. The structures of A2MORPH and A2NMF were solved in 𝑃ī, whereas A2NMA 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 (A26ANI) and morpholine (A26MORPH). A26MORPH and A26ANI crystallised in the space groups Pc and 𝑃ī respectively. The packing of these structures are characterized by (Host)-OHO-(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.

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.

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.

Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1980 / Includes bibliographcial references. / by Farhad Hakimi. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Thesis (M.S.)--Mississippi State University. Department of Chemistry. / Title from title screen. Includes bibliographical references.

Thesis (Ph.D.)--Mississippi State University. Department of Chemistry. / Title from title screen. Includes bibliographical references.