We have investigated crystal structures and physicochemical properties of AgSO3CF3 and AgSO3F. Their thermal decompositions were also investigated.
COBISS.SI-ID: 25559847
Disslution of oxides MO (M = Zn, Cu, Hg) in superacid aHF/AsF5 or reaction between H3OAsF6, FeF2 and AsF5 in aHF as a solvent yield H3OM[AsF6]3 (M = Fe, Zn), H3OMF(AsF6)2 (M = Fe, Cu) and (H3O)2Hg2F(AsF6)5. The H3OMF(AsF6)2 (M = Fe, Cu) crystal structures consist from zig-zag [–M–F–M–] chains with a pronounced antifferomagnetic interactions within the chains.
COBISS.SI-ID: 25711143
Heterogeneous reactions of trifluoromethane (CHF3) with solid alkali hydroxides and carbonates were investigated at moderate temperatures. In all cases, main reaction is fluorination characterised by a complete decomposition (mineralization) of the fluorinating agent, CHF3, and the formation of solid metal fluorides, CO, and H2O. Under specific conditions, CO and H2O may react further through the water-gas shift reaction and form solid metal carbonate. Extent of fluorination strongly depends on temperature and is dictated by the nature of the solid precursor. Alkali hydroxides, KOH, NaOH, and LiOH, are the most reactive solids that start to react with CHF3 at relatively low temperatures, 370–484 K. Onset temperatures for fluorination of corresponding carbonates are 100–150 K higher. Reactivity of the solids towards CHF3 can be correlated with their basicity. Reactions are rationalised on the basis of an acid-base type of interactions between CHF3 as a very weak C–H acid and the very strong basic oxygen species in the solids. These interactions apparently play a decisive role during the initial binding of CHF3 molecule to the solid reactant, in this way enabling or facilitating other decomposition steps that finally lead to a complete destruction of the CHF3 molecule. Total decomposition of CHF3 with KOH or NaOH, achievable at relatively very low temperatures, could in some specific cases represent a possible alternative to the energy-demanding CHF3 decomposition by incineration.
COBISS.SI-ID: 26006311
Human exposure to the fluoride (F) from some of the best-selling teas of different types and forms available in Slovenian and in most of the European markets was assessed. The efficacy of F leaching from the black, oolong and green teas is not affected by the type or by the manufactured form of the tea. The final concentration of bioavailable F in tea infusions is dependent on the content of total fluorine in the tea only and ranges between 55–90% with continuous, and 74–100% by repeated, infusions. The highest contents of total fluorine can be found in the teas in bags. The daily intake of F with tea can represent 9–101% of the adequate intake (AI) and with tea and diet 25–173% of the AI in non-fluoridated, and 35–210% of AI in fluoridated, areas.
COBISS.SI-ID: 24952871
In this study we have shown that VOF3 is a useful precursor for convenient room temperature synthesis of fluoridomonooxidovanadates(V), by the interaction of it with fluoride anion in anhydrous HF. As exemplified in the case of Pb(V2O2F8) and Pb(VOF5) the type of anion formed is governed by the molar ratio between VOF3 and F−. Additionally, it is evident that central vanadium(V) atom tends to assume pseudooctahedral environment with an elongated V−F bond trans to the short V=O. The fluorine atom for the former bond can be supplied by another VOF4− anion as in Pb(V2O2F8) or by F− as in Pb(VOF5) or even by VF62− as evident in compound Pb3F(V4O3F18). The latter example opens a possibility for targeted syntheses of this rare type of anions by interaction of VOF3 or VOF4− with VF6n− (n = 1, 2, 3) or with other fluoridoanions.
COBISS.SI-ID: 26019111