Some nitronium and nitrosonium salts of some strong acids

Thorley, John (1965) Some nitronium and nitrosonium salts of some strong acids. PhD thesis, University of Glasgow.

Abstract

A series of compounds, reported in the literature, which can be formulated as nitrosonium salts of fluoro-acids, have been re-prepared. Several metal chloride-nitrosyl chloride adducts, also reported in the literature, have been re-prepared, and both those groups of compounds have been shown to contain the nitrosonium ions No+, by infrared diagnostic methods. The isomorphism of the nitrosonium salts of the anions fluoroborate, chlorostannate and chloroplatinate with their potassium analogues has boon confirmed, and nitrosonium and potassium fluorosulphates have been shown to be isostructural. These observations have been enplaned structurally, with reference to the relative sizes of nitrosonium and halide ions. The free (i.e. unco-ordinated) nitrosonium ion was found to absorb in the region 2160 cm-1 - 2400 cm-1. This wide variation was partially e:tplicabie in terms of polarisation by the anion but it is apparent that other factors were important, In generals it was found that fluoro-acid salts gave the highest nitrosonium ion stretching frequencies, followed by oxy-acid salts and chloro-acid salts respectively. The behaviour of group IVB and VB Lewis acid halides was observed with nitrogen oxides and nitrosyl chloride. With dinitrogen tetroxide, all the compounds examined, except arsenic trichloride, gave a mixture of products which it was not possible to separate. Arsenic triohloride gave a nitrosonium nitrato-arsenate salt. In the other cases, there was evidence for the formation of nitrosonium and nitronium salt mixtures, in accord with earlier observations on the behaviour of dinitrogen tetroxide with Lewis acids, and strong acids such as perchloric acid. With nitrosyl chloride, the products were either nitrosonium chloro-acid salts or molecular adducts. Reactions involving nitric oxide were not investigated extensively but in reactions with high valency metal chlorides, the primary reaction step was always a reduction by the nitric oxide. The behaviour of transition metal chlorides and oxides of the titanium, vanadium and chromium groups was observed in nitrosyl chloride and dinitrogen tetroxide. These reactions could all be explained assuming auto-ionisation of the solvent. The reactions in nitrosyl chloride yielded mainly nitrosonium salts of chloro-acids, and several of the anions thus formed were bi- and tri- nuclear species. The previously reported compounds NO.VCl4 and NO.V2Cl7 were obtained and characterised as nitrosonium salts. With niobium and tantalum, the new compounds NO.NbCl6 and NO.TaCl6 were prepared, containing the previously unknown NbCl6- and TeCl6 anions. The new compounds (NO)3Cr2Cl9 and (NO)3Mo3Cl10 were obtained. A surprising feature of several of these ionic compounds was their high volatility. In the reaction between chromium (VI) trioxide and nitrosyl chloride, a new compound (NO)2 Cr3O8Cl was characterised, in which chromium has undergone a partial reduction. Vanadium pentoxide underwent a similar reaction, but in this case it was not reproducible. The reactions involving dinitrogen tetroxide generally gave rise to one product only, in contrast to the Lewis acid dinitrogen tetroxide reactions. The products were usually metal nitrate-dinitrogen tetroxide adducts and these could be formulated as nitrosonium metal nitrato-salts, on the basis of their infrared spectra. Vanadium and chromium chlorides gave the adducts VO2NO3.N2O4 and Cr(NO3)3.2N2O4 respectively, but molybdenum trichloride gave Mo(V)O(NO3)3 which may be polymeric. No reaction occurred between chromium (III) chloride and either nitrosyl chloride or dinitrogen tetroxide, but in the presence of chromous chloride, reaction proceeded readily in both instances. No reaction was observed between high valency metal oxides and dinitrogen tetroxide, but this may have been due to insufficiently vigorous conditions. The reflectance spectra of the majority of the above compounds were observed, and, in most cases it was possible to make satisfactory band assignments.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: D WA Sharp
• Keywords: Inorganic chemistry
• Date of Award: 1965
• Depositing User: Enlighten Team
• Unique ID: glathesis:1965-73424
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73424