solvent effects on complexation of dioxovanadium (v) with glycine in methanol-water mixtures

the formation constants of the species formed in the systems fr + glycine + dioxovanadium(v) + and h+ + glycine have been determined in aqueous solutions of methanol at 25 °c and constant ionicstrength, using spectrophotometric and potentiometric techniques. it was shown thatdioxovanadium(v) forms two mononuclear 1 : land 1:2 complexes with glycine. the formationconstants in various media were analyzed in terms of kamlet and taft's parameters. single-parametercorrelation of the formation constants, 13 and 13122, versus a (hydrogen-bond donor acidity) and f3(hydrogen-bond accepter basicity) are poor in all solutions, except for le (dipolarity/polarizability), butmulti-parameter correlation represents significant improvement with regard to the single-parametermodels. linear relationship are observed when logp and logf3 1,2 are plotted versus re. finally, theresults are discussed in terms of the effect of solvent on complexation.