Lanthanide-induced shifts were measured for 13C and 1H nuclei of glycyl-DL-valine in the presence of three lanthanide cations (La3+, Ho3+ and Yb3+) in aqueous solution The stability constants of the coordination compounds of rare earths (Ho, Yb) with glycyl-DL-valine were calculated The coordination of rare earths with the ligand is discussed. The simulation for conformation of lanthanide coordination compounds with glycyl-DL-valine shows that the ligand is coordinated to lanthanide ion through oxygen atoms of carboxyl group and the bond length of Ln-O is 0.226 nm. In the coordination compounds, glycyl-DL-valine is in extended state with minimal steric hindrance.

Key words: AQUEOUS SOLUTION, NMR SPECTROMETRY, STABILITY CONSTANT, HOLMIUM COMPLEX, YTTERBIUM COMPLEX, LANTHANUM COMPLEX, CONFORMATION, COORDINATION, GLYCINE P