Solid RE(III)-ATP complexes [RE = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu] were synthesized and characterized through IR, laser-Raman, TGA, UV-visible, ESR, x-ray, elemental anal., complexometric titration and other experiments as RE(HL)(H2O)4 (H4L = ATP). The electronic structure of the series were calculated by INDO and the nature of high energy P-O bond in biol. chem. is discussed.

Key words: ULTRAVIOLET SPECTROPHOTOMETRY, BIOLOGICAL ACTIVITY, INFRARED SPECTROPHOTOMETRY, THERMAL ANALYSIS, ELEMENTAL ANALYSIS, MOLECULAR STRUCTURE, X-RAY DIFFRACTION ANALYSIS, QUANTUM CHEMISTRY, ADENOSINE TRIPHOSPHATE, PARAMAGNETIC RESONANCE