2026-09-27T20:24:02Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/19646 2023-07-10 col_2142_5131 col_2142_14789 com_2142_5130 com_2142_14788 com_2142_8903

ETDs are only available to UIUC Users without author permission U of I Only AAI9124389 (UMI)AAI9124389 http://hdl.handle.net/2142/19646 eng Copyright 1991 Chae, Hee Kwon Chemistry, Inorganic Engineering, Materials Science Klemperer, Walter G. Chae, Hee Kwon 2011-05-07T12:14:01Z 2011-05-07T12:14:01Z 10000-01-01 1991 Part I. Hydrothermal methods were developed for the growth of mm-sized crystals of dodecasil-3C clathrasils, 17 SiO$\sb2\cdot$M (M = pyridine, cyclopentane, cyclohexane, piperidine, pyrrolidine, cyclopentylamine, and cyclobutylamine). Reaction conditions were optimized for large, chemically pure dodecasil-3C (D3C) crystals. For the synthesis of pyridine, cyclopentane, and cyclohexane D3C crystals, an aqueous pyridinium bifluoride solution was used as a catalyst. Phase transformations of pyridine D3C crystals were determined by differential scanning calorimetry to commence at 161$\sp\circ$C and $-$46$\sp\circ$C on cooling. The crystal structure of the ambient temperature tetragonal 17 $\rm SiO\sb2{\cdot}C\sb5H\sb5N$ phase was determined using single crystal X-ray diffraction techniques which revealed that the Py-D3C crystals were acentric at ambient temperature and thus second harmonic generators. All other clathrasils synthesized were also tetragonal at ambient temperature, and underwent a transformation to a cubic phase at elevated temperatures, as well as a transformation to a lower symmetry phase at lower temperatures. The size of the guest molecule had a large influence on the phase transition temperatures, with larger guest molecules raising the temperature of the high temperature transition and lowering the temperature of the lower temperature transition. The methodology for synthesizing large D3C crystals was applied to form the dodecasil-1H (D1H) phase with adamantane. Part II. The reaction of (($\rm C\sb5 Me\sb5)Rh(OH)\sb2\rbrack \sb2$ with $\rm V\sb2O\sb5$ in water has yielded ($\rm (C\sb5Me\sb5)Rh\rbrack \sb4 (V\sb6O\sb{19})$ (1). The crystal structure of 1, determined by Dr. Victor Day at Crystalytics Company in Lincoln, NE, revealed the presence of a neutral complex in which four Cp*Rh$\sp{2+}$ cations are bound to a single $\rm V\sb6O\sb{19}\sp{8-}$ anion. This approach can be extended to the synthesis of $\{\lbrack \rm(C\sb5Me\sb5)Rh\rbrack \sb8Mo\sb{13}O\sb{40}\}Cl\sb2$ (2) by the hydrothermal reaction of (($\rm Cp*Rh)\sb2 (OH)\sb3\rbrack Cl$ with MoO$\sb3 \cdot$2H$\sb2$O. In this crystal structure, each of the eight Cp*Rh$\sp{2+}$ cations is bound to three of the twenty-four doubly bridging oxygens of a Mo$\rm\sb{13}O\sb{40}\sp{14-}$ anion. The Mo$\rm\sb{13}O\sb{40}\sp{14-}$ core was determined to be an $\varepsilon$-Keggin isomer. Made available in DSpace on 2011-05-07T12:14:01Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9124389.pdf: 4956804 bytes, checksum: bbc8d7aa9304ac52792ad8e48c94ccfd (MD5) Previous issue date: 1991 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:38:28Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:16:02-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission Part I. Clathrasil chemistry: Synthesis and characterization of dodecasil-3C and dodecasil-1H clathrasils. Part II. Synthesis and structure of pentamethylcyclopentadienyl rhodium vanadium and molybdenum oxides text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.