Difluorophosphoric acid was purified by a double distillation technique. Alkali metal difluorophosphates were prepared by reaction of the metal chlorides with purified difluorophosphoric acid; x-ray powder photographs and infra-red spectra of the salts were obtained. Electrical conductivity measurements were made on solutions of the alkali metal difluorophosphates in difluorophosphoric acid as solvent. The order of mobility of the alkali metal cations in this solvent was found to be Li>Na>K>Rb>Cs. Results indicate that the difluorophosphate ion does not conduct by a proton transfer process in this solvent. Conductimetric studies on solutions of a number of other compounds in difluorophosphoric acid are also reported. / Science, Faculty of / Chemistry, Department of / Graduate

Twenty-seven difluorophosphates are successfully prepared by the displacement reactions of anhydrous chlorides or arylcarboxylates with purified difluorophosphoric acid. Vibrational spectra are obtained for these difluorophosphates and assignments made. The effects of cation-anion interactions on the vibrational frequencies of the PO₂F₂ group are also examined. Mossbauer parameters for five dialkyltin bis-difluorophosphates are reported and compared with those of analogous fluorosulfate derivatives. Electrical conductivity, nuclear magnetic resonance and density studies of solutions of some metal difluorophosphates in difluorophosphoric acid are made in an attempt to obtain a better understanding of solution behaviour in difluorophosphoric acid. / Science, Faculty of / Chemistry, Department of / Graduate

The physical and inorganic chemistry of solutions in difluorophosphoric acid, HPO₂F₂, has been studied, as part of a general study of solutions in non-aqueous protonic solvents. Difluorophosphoric acid is a colourless, associated liquid which might be expected to have solvent properties similar to those of other protonic systems such as H₂O, H₂SO₄ and HSO₃F. However, electrical conductivity studies of solutions of various electrolytes and nuclear magnetic resonance studies of solutions of alkali metal difluorophosphates indicate that the acid is a poor solvent for electrolytes and that ion-pairing is probably extensive. Acid-base behaviour in HPO₂F₂ has been extensively investigated. Compounds which behave as bases in this system include metal difluorophosphates, chlorides, nitrates and carbonates, organic amines, and some organic nitro-compounds and carboxylic acids. Inorganic molecules such as H₂SO₄, HSO₃F and SbF₅ behave as acids. Reaction between an acid and a base in HPO₂F₂ commonly result in the formation of an insoluble salt. The reaction between KPO₂F₂ and SbF₅, for example, has been used to prepare the new compound KSbF₅PO₂F₂. To further investigate the factors affecting acid strengths, cryoscopic and electrical conductivity studies of various inorganic oxy-acids were carried out in nitrobenzene, as solvent. The acids H₂SO₄, HSO₃F and HPO₂F₂ appeared to be virtual non-electrolytes in nitrobenzene, with H₂SO₄ apparently exhibiting some polymerization. / Science, Faculty of / Chemistry, Department of / Graduate