Topics in the Chemistry of Main-Group and Transitional-Metal Fluorides

Harman, Mary Elizabeth (1974) Topics in the Chemistry of Main-Group and Transitional-Metal Fluorides. PhD thesis, University of Glasgow.

Abstract

Phosphnylamines, Cl2P(O)NHR (R = Me, Et and Ph) , were obtained by the reaction of amine hydrochlorides, RNH2. HCl,, with phosphoryl chloride, P(O)Cl3. Fluorination of these derivatives by sodium fluoride produced the compounds F2P(O)NHR. Bis(dichlorophosphinyl)amines, [Cl2P(O)]2NR, and their fluoro- derivatives were synthesised by the condensation of the phosphinylamines with phosphoryl halides, P(O)FnCl3-n, in the presence of a tertiary amine. The difluoro- derivative. [FClP(O)]2Me, was obtained as a mixture of diastereoisomers from the reaction of heptamethyldisilazane, (Me3Si)2NMe, with P(O)FCl2. Attempts to synthesise the difluoro-compounds, Cl2P(O)NRP(O)F2, from F2P(O)NHR and P(O)Cl3 resulted in the formation of impure products. Possible reasons for this are discussed. The trifluoro- compounds, F2 P(O)NRP(O)FCl, were not prepared. 1H, 19F and 31P n. m. r. data are given for the diphosphinylamines synthesised, together with their infrared and mass spectra. The spectra are compared with those obtained from the phosphinylamines. Heptamethyldisilazane, (Me3Si)2NMe, and tungsten hexafluoride, WF6, reacted in the absence of a solvent to produce a white solid formulated as WF4 NMe and in the presence of MeCN to produce the complex WF4NMe.HeCN. The coordinated MeCN could be displaced by C5H5N (py) forming the complex WF4NMe. py. The adducts were characterised by elemental analyses and by n. m. r. and mass spectroscopy. Their spectra, together with those of WF4NMe.CD3CN and WF4NMe.C5D5N, are presented and discussed. Possible structures for both WF4NMe and WF4NMe. MeCN are suggested. A preliminary investigation into the chemistry of WF4NMe.MeCM showed that the fluorine atoms could be replaced but that the compound did not react with SF5Cl, SO2 or CS2. Hexamethyldisilazane, (Me3Si)2NH, and WF6 reacted in the presence of MeCN to produce a solid whose elemental analysis, infrared and n. m. r. spectra suggest that it has the composition NH4+WOF5- .MeCN. A reaction carried out between MoF6 and (Me3Si)2NMe in MeCN suggests that NoF6 reacts in a manner similar to that described for WF6 but that the reaction products are more susceptible to hydrolysis. Sulphur chloride pentafluoride, SF5-Cl, reacted exothermically with the chlorophosphines PhPCl2 and Ph2PCl to produce the corresponding fluorophosphoranes PhPF4 and Ph2PF3 along with SCl2 and Cl2. When SF5Cl reacted with MePCI2, although the phosphorane MePF4 was formed, the major product was a white solid which analysed as CH2 3Cl5 FP but which was not further characterised. The reactions between SF5Cl and the halogen free derivatives P(NMe2)3 and P(OMe)3 produced SF4, Cl2 and other products which were not completely identified but for which structures are suggested. SF5Cl did not react with either PPh3 or PCl3. Reaction schemes for these oxidative fluorinations by SF5Cl are presented and discussed. A detailed analysis of the vibrational spectra of CF3SF4Cl was carried out. This confirmed the evidence from n. m. r. spectroscopy that only the trans isomer of the compound is obtained from the synthesis involving CF3SF3, Cl2 and CsF. The infrared and Raman spectra of other substituted derivatives of SF6, CF3,SF4, CF2CF2Cl, SF5CF2CF2Cl and SF5CH=CH are presented and discussed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Inorganic chemistry
• Date of Award: 1974
• Depositing User: Enlighten Team
• Unique ID: glathesis:1974-78665
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:04
• Last Modified: 30 Jan 2020 15:04
• URI: https://theses.gla.ac.uk/id/eprint/78665