Call number: LD2668 .T4 1963 H37 / Master of Science

A pulsed-beam fourier transform microwave spectrometer was used to measure the rotational spectra of iodine heptafluoride, iodine pentafluoride, and the weakly bound complex, HCl...NNO. For IF7, only five rotational transitions were observed, and no resolvable hyperfine structure was detected. Based on this data, the A, B, and C rotational constants were determined to be 1746(3) MHz, 1732.0(8) MHz, and 1553.0(2) MHz, respectively. The existence of a pure rotational spectrum confirms that this molecule undergoes polar distortions. Twenty-two hyperfine components of the IF5 spectrum were recorded. The B rotational constant for this molecule was determined to be 2727.421(3) MHz, and the quadrupole coupling constant was found to be 1069.35(13) MHz. Though the work is still in progress on HCl...NNO, nine transitions have been recorded. In addition, five transitions have been recorded for an apparent trimer species composed of HCl, NNO, and an as yet unidentified third species.

Sulfur trioxide (SO₃) adds to fluoroolefins of the form RCF=CF₂, (where R = F, SF₅, CF₃, CF₃OCF₂, CF₂=CF(CF₂)₂, CF₃(CF₂)₃O, CF₃O(CF₂)₂OCF₂, or CH₂ClCHClCH₂), yielding the fluorinated [beta]-sultones, RCFCF₂OSO₂. In the case of CF₃(CF₂)₃OCF=CF₂, a reverse addition occurs, giving the sultone, CF₃(CF₂)₃CF₂2OCFCF₂SO₂O. The fluoro [beta]-sultones are capable of undergoing different reactions, such as rearrangement, hydrolysis, esterification, and polymerization. These reactions, will result in the formation of compounds containing the fluorosulfonyl grouping (SO₂F); it is this group that yields the corresponding sulfonic acid upon base/acid treatment. The addition of sodium bisulfite to CF₃CF= CF₂ and CF₃(CF₂)₄CF=CF₂ in the presence of (C₆H₅CO)₂O₂ and Na₂B₄O₇·10H₂O was also studied to produce the corresponding sulfonic acid hydrates of the general formula, R[subscript f]CFHCF₂SO₃H·nH₂O. These acids were prepared, and thus, tested as possible fuel cell electrolytes. Infrared, ¹H and ¹⁹F nuclear magnetic resonance and mass spectra, as well as elemental analyses, will be presented in order to support the proposed structures for the resulted compounds.

The purpose of this thesis was two fold: (i) The synthesis and characterization of SF5 containing dienes. (ii) The characterization of hydro/fluorocarbon compounds containing SF5/S02F groups via their 13C NMR spectra. A new SF5CH2CHBrCH2CF=CF2 was prepared and characterized as a precursor to new dielectric polymers. This new adduct was made from the reaction of pentafluorothio bromide with l,l,2-trifluoro-1,4-pentadiene. A SF5-diene was prepared from the reaction of pentafluorothio chloride with acetylene. This reaction involves a radical addition mechanism. The SF5 group is bonded to the carbon atom carrying the most hydrogens. SF5 - dienes are capable of undergoing different reactions, such as polymerization. Fluorocarbon sulfonyl fluorides (RS02F), which have been synthesized in our lab, were characterized by their 13C NMR spectra. The 13C NMR data of these sulfonyl fluorides show chemical shift values for the methyl and methylene groups next to a fluoroalkyl sulfonyl fluoride group in the 52.8-65.7 ppm range. The spectra showed that the inductive effect of electronegative substituents has a major influence on the 1Jc-F and 1Jc-H coupling. Infrared, 1H, 19F and 13C nuclear magnetic resonance and mass spectra are presented to support the assigned structure for the new compounds, SF5CH=CHCH=CHC1 and SF5CH2CHBrCH2CF=CF2.

ABSTRACT PELCHEM, the chemical division of NECSA, produces the fluorocarbon hexafluoropropylene (HFP) onsite. In 2005 PELCHEM initiated research into the wet oxidation of HFP to produce the higher value fluorocarbon hexafluoropropylene oxide (HFPO). Although successful in the conversion of HFP to HFPO, the product stream contained both the product and the unreacted HFP. As a result, PELCHEM contracted the Thermodynamics Research Unit at the University of KwaZulu-Natal to investigate the separation of HFP and HFPO. A solvent selection procedure was used to identifY potential solvents and an initial list of two hundred and seven candidate solvents compiled. Utilising the UNIFAC group contribution method, the initial list was narrowed down to thirty solvents using the criterion of selectivity at infinite dilution. Through the comparison of specific solvent properties such as recoverability, safety, environmental factors and economic considerations, a final list of ten solvents was generated. The list of ten solvents was proposed to PELCHEM who identified four solvents for further studies. The work involving the two solvents, toluene and hexafluoroethane (RI 16), is presented in this dissertation. The solvent toluene has been previously used by the du Pont company for the separation of HFP and HFPO, while R116 is a novel solvent for this application. The solvent selection procedure was performed in collaboration with a member of the Thermodynamics Research Unit, and the work on the remaining two solvents is presented in the dissertation of (Nelson 2008). Experimental binary high pressure vapour liquid equilibrium data were measured for the HFP + toluene, HFPO + toluene, R116 + HFP, and R116 + HFPO systems at two temperatures: 273.15 and 3 13.15 K. Pure component vapour pressure data for HFPO in the temperature range of 271.90 to 318.20 K were also measured. The HPVLE measurements were performed at the Thermodynamics Energy and Phase Equilibria laboratories at Ecoles des Mines de Paris using two experimental techniques and equipment. The binary systems involving toluene were measured on a static synthetic Pressure Volume Temperature apparatus equipped with a variable volume cell. The binary systems involving RI16 were measured on a static analytic apparatus equipped with a Rapid On-line Sampler Injector. None of the systems measured for this project have been reported in the literature. The four binary systems and the pure component vapour pressure measurements thus constitute new data sets. All experimental data were modelled via the direct method using the computer software Thermopack. Three model combinations were used to represent the data: the Peng-Robinson equation of state with the Wong-Sandler mixing rules, the Peng-Robinson equation of state with the Modified-Huron-Vidal first order mixing rules, and the Soave-Redlich-Kwong equation of state with the Wong-Sandler mixing rules. The Mathias-Copeman alpha function was used in conjunction with the equation of state models, and the NRTL activity coefficient model was incorporated into the mixing rules. Due to time constraints, experimental data for the binary system HFP + HFPO were not measured. Data for this system was predicted at two temperatures, 273.15 and 313.15 K, via the PSRK-UNIFAC method. The critical line for the supercritical systems R116 + HFP and R116 + HFPO were calculated in Thermopack. PELCHEM required a commercial grade HFPO product stream of purity greater than 99 % (mole), and a purified HFP product stream of purity greater than 95 % for the recycle and conversion of HFP into HFPO. Using the regressed experimental high pressure vapour liquid equilibrium data, two preliminary separation processes were designed in Aspen Plus to achieve these objectives. The first scheme involved toluene and utilised the process of extractive distillation with toluene introduced as a liquid solvent. The toluene bonded to the HFP and was removed as a bottoms product which allowed a purified HFPO stream to be recovered as a distillate. The second scheme involved RI16 and utilised the process of gas stripping, with a liquid mixture of HFP and HFPO contacted with a gaseous stream of R116. The R116 removed the HFP from the liquid mixture, resulting in a purified HFPO stream. The toluene process resulted in an overall HFPO product recovery of 98.46 % and HFPO product purity of99.88 % (mole). The RI16 process resulted in an overall HFPO product recovery of96.57 % and HFPO product purity of99.71 %. For the component HFP, the toluene process resulted in an overall HFP product recovery of 99.42 % and product purity of96.41 %. The RI16 process resulted in an overall product recovery of99.36 % and product purity of93.45 %. From a comparison of the preliminary design of the separation processes on the basis of patent issues, performance, and other miscellaneous factors, it was concluded that the RI16 process compared favourably to the process involving the solvent toluene. The preliminary process designs were presented to PELCHEM in 2007, and pending further experimental work PELCHEM plans to patent the RI16 separation process. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2008.

Typescript (photocopy) / 2 microfiche in end pocket / 190 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, 1984

Thesis (Ph.D.) -- University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1984. / Typescript (photocopy). 2 microfiche in end pocket.

Part I describes the preparation of a number of useful intermediates from the sultone F5SCHCF2OSO2 (1). These intermediates include the following: the ketene F5SC(SO2)=C=O (21), the unique sultone F4S=CCF2OSO2 (23), and various ionic intermediates of the form Y+ [F5SC(SO2F) COX]-. These intermediates play an important role in providing new pathways for preparing fluorosulfonic acid precursors. Fluorosulfonic acids are excellent candidates to improve the efficiency of environmentally safe fuel cells. It was possible to obtain new derivatives of 1 by various reactions of 21, 23 and the ionic intermediates, but it was not possible to introduce an alkyl substituent with either of the intermediates. Part II is concerned with the synthesis of SF5 containing epoxides as possible monomers. When polymerized, materials of high dielectric strength and high chemical resistance should be obtained. The reaction chemistry of one of the epoxides was investigated and it was found that all reactions studied were accompanied by the loss of the SF5 group. Thus, it was not possible to obtain any polymeric materials. Part III deals with the synthetic accessibility of SF$\sb5$ malonic esters and thence of SF$\sb5$ acrylic esters. These compounds should serve as building blocks in the synthesis of SF$\sb5$ containing pyrimidines. The CF3 analogue, 5-trifluoromethyl uracil, is used as an antiviral drug. In order to synthesize either SF5 malonic ester or 2-SF5 acrylic ester an SF5 group has to be introduced at a secondary carbon. A secondary SF$\sb5$ compound could be synthesized (F5SCH (COOC2H5) (CHBrOAc)) but could not be converted to the respective malonic ester F5SCH (COOC2H5) compound. Part IV describes the reactions and preparations of Parts I-III.

This thesis is concerned with the synthesis and characterisation of novel TCNQ (7,7,8,8-tetracyanoquinodimethane), TMTCNQ (2,3,5,6-tetramethyl-7,7,8,8-tetracyanoquinodimethane) and TCNQF4 (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) based zwitterionic D-1t-A materials (where D and A are electron donors and acceptors respectively) of which the methylated Z-~-(N-methyl-4-quinolinium)-a-cyano-4( 2,3,5,6-tetrafluoro)styryldicyanomethanide [CH3(4)Q3CNQF4] is a typical example. Synthetic modification of the donor moiety was also undertaken, resulting in a diverse range of pyridinium, quinolinium and benzothiazolium-based materials, which may have use in nonlinear optical research. For the quinolinium system an extensive range of both 2- and 4-substituted analogues have been prepared and their properties compared and contrasted. The solvatochromic behaviour of these zwitterions was investigated in detail by dissolution in a range of organic solvents and measurement of their longest wavelength charge-transfer absorption bands using UV/Visible spectroscopy, which revealed that the substituents have a marked effect upon their solvatochromic properties. Most of the adducts studied display highly negative solvatochromism as the solvent polarity increases, in which their absorption maxima are linearly related with the normalised ENT values for the Reichardt dye. However the fluorinated quinolinium and pyridinium derivatives exhibit an unusual aggregation-induced reverse solvatochromism effect. The negative halochromic behaviour of selected zwitterions has also been investigated, with a hypsochromic shift of the longest wavelength CT absorption band being observed upon addition of electrolytes. Increased polarisation within the fluorinated R(4)Q3CNQF4 and R(2)Q3CNQF4 adducts has been indicated by solution state dipole moment measurements indicating greater nonlinear optical potential. However this increased polarisation has also been shown to be a major cause of the limited stability of these materials to photo-oxidation. The behaviour of the R(4)Q3CNQF4 and R(2)Q3CNQF4 zwitterions on the subphase and their resultant Langmuir-Blodgett film forming ability was also studied. However unlike the TCNQ-based materials the fluorinated adducts have been shown to be poor LB film forming materials.

Kwoli Chui. / "August 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 122-140). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.