Chemistry of some metals and fluorides in pure nitric acid and high density red fuming nitric acid

The work presented in this thesis is partly concerned with the reactions of some metals (Bi, U, V) with 100% HNO3 and the mixture of composition ca. 56 wt% HNO3 - 44 wt% N2O4, known as High Density Acid (HDA). Both bismuth and uranium react to give solid products formulated as 'mixed adducts' of Bi(NO3)3 or UO2(NO3)2 with N2O4 and H2O. Vibrational spectroscopy shows these compounds to be nitrosonium nitrato-complexes. X-ray powder diffraction data are presented for the bismuth products. On the other hand, both the solid and solution products obtained by the reaction of vanadium with 100% HNO3 and HDA, were found to be linear chain V-O polymeric species in which the vanadium atom is co-ordinated to at least four oxygen atoms. Vibrational spectroscopy and X-ray powder diffraction results are reported. 51V and 14N n.m.r. spectroscopic studies of V/100% HNO3 solution are presented. The reactions of BF3 with 100% HNO3 and HDA, at low concentrations of BF3, were investigated mainly by 11B and 19F n.m.r. spectroscopy at room temperature and lower temperatures. The reactions of HDA solutions of aluminium with HF are also reported. The results are discussed. (author)