Solvate state of some rare earths(3) in aqueous-dimethylformamide media

Stoichiometry, formation constants, stereochemical parameters of solvate forms realizing in the systems Ln3+(Tb3+, Ho3+, Er3+, Tm3+, Yb3+)-H2O-DMFA are determined. Outerspheric coordination of one DMFA molecule precedes the formation of innerspheric heterosovates. In the course of substitution of water molecule for DMFA molecule in the first coordination sphere and as cation size decrease reduction of coordination number (up to 6 in heterosolvate [Yb(DMFA)4(H2OP)2]3+) is observed. 7 refs., 2 figs., 1 tab