UNT Theses and Dissertations - 5 Matching Results

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Aqueous Solubilities and Transformation of Chlorinated Benzenes

Description: Aqueous solubilities of twelve chlorinated benzenes were determined by two methods. In one method, the solutions in water were prepared by a vigorous stirring method followed by n-hexane extraction and GC-ECD analysis. In the second method, HPLC was used to prepare the saturated solutions. Experimental results were compared with the predictive values, the relative standard deviations are around 10%. Most of the chlorinated benzenes exhibit water induced transformations. The transformation produ… more
Date: August 1990
Creator: Wang, Hui-Wen
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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A Kinetic Study of the Recombination Reacton Na + SO₂ + Ar

Description: The recombination reaction Na + S02 + Ar was investigated at 787 16 K and at pressures from 1.7 to 80 kPa. NaI vapor was photolyzed by an excimer laser at 308 nm to create Na atoms, whose concentration was monitored by time-resolved resonance absorption at 589 nm. The rate constant at the low pressure limit is ko = (2.7 0.2) x 10-21 cm6 molecule-2 s~1. The Na-SO 2 dissociation energy E0 = 170 35 kJ mol1 was calculated with RRKM theory. The equilibrium constant gave a lower limit E0 > 172 kJ mol… more
Date: December 1990
Creator: Shi, Youchun
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Photochemical Silaylide, Silylene and Silene Syntheses

Description: The synthesis of o-(N,N-dimethylamino)methylphenyl tris (trimethylsilyl) silane (II), a photochemical precursor of o- (N,N-dimethylamino) methylphenyl (trimethylsilyl) sila ammonium ylide (intramolecular silylene complex) and otolyl(trimethylsilyl)silylene is reported. Photolysis of II at room temperature in a cyclohexane solution of triethyl silane produced the silylene ylide and the presumably uncomplexed isomer, a silylene, which is trapped to afford the 2-(o-(N,N-dimethylamino)methylphenyl)… more
Date: August 1990
Creator: Tan, Changqing
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Syntheses and Structures of Substituted Polycyclic Molecules and Analysis of the Two-Dimensional NMR Spectrum of Thiele's Ester

Description: Diels-Alder cycloaddition of methylcyclopentadienes to 2,5-dibromo-p-benzoquinone was performed. A single, isomerically pure cycloadduct was isolated, whose structure was assigned via analysis of its 1-D and 2-D NMR spectra. Diels-Alder cycloaddition of methylcyclopentadienes to 2 -methoxy-p-benzoquinone was performed. A single, isomerically pure cycloadduct was isolated, whose structure was assigned via analysis of the 1-D and 2-D NMR spectra of this cycloadduct and its reduction product obtai… more
Date: May 1990
Creator: Lu, Shao-Po
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis, Structure, and Solution Dynamics of Co₄(CO)₈(dmpe)(mu₄-PPh)₂

Description: Reaction of the tetracobalt cluster Co4(CO)10(t 4-PPh)2 with 1,2-bis(dimethylphosphino)ethane (dmpe) affords the bis-substituted cluster Co4(CO)8(dmpe)(t 4-PPh)2. The bidentate dmpe ligand is shown to bind to the cluster in a chelating fashion by IR, NMR, and X-ray diffractions analyses. The fluxional nature of the ancillary carbonyl groups has been studied by variable temperature 13C NMR measurements which reveal two distinct carbonyl scrambling pathways. The stability of the phosphine-ligated… more
Date: May 1990
Creator: Schulman, Cheryl Lutins
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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