Sazonova O. Isopoly- vanadate, tungstate and vanadatotungstate anions in agueous solutions and in composition of crystal salts

The thesis is devoted to the investigation of isopoly - vanadate, tungstate and vanadatotungstate anions in agueous solutions and to the synthesis of salts containing these anions. The mathematical models, which describe formation of isopolyanions in VO43- - H+ - H2O, WO42- - H+ - H2O, VO43- - WO42- - H+ - H2O systems at concentrations Cмo4n-=10-3-10-1 моl/l at ionic strength 0,1-0,5 моl/l, have been elaborated. The concentration and thermodynamic constants of isopolyanion formation have been calculated, the existence ranges of isopolyanions have been determined, the dependence of composition on concentration and ionic strength of solutions has been established. The thermodynamic characteristics of intertransitions between anion forms depending on medium acidity have been calculated. The synthesic procedures for 11 novel isopolyoxometalates containing cations Na+, Tl+, Nd3+ have been developed. The structure and properties of salts have been characterised by IR-spectroscopy, thermogravimetric and X-ra y powder diffraction.