The coordination reactions of dibenzo-18-crown-6 with lanthanide perchlorates except Pm, Lu in anhydrous acetonitrile were investigated at 298.15K by titration calorimeter. The formation constants and enthalpies of coordination reactions were calculated using computer program made by ourselves. The changes of free energy and entropy of every coordination reaction were obtained. The influences of lanthanide cations(III) on the coordination reactions were discussed. Comparisons were also made on the thermodynamic properties for coordination reaction of lanthanum perchlorate with dibenzo-18-crown-6 and with other crowns in anhydrous acetonitrile, respectively.

Key words: COORDINATION REACTION, ACETONITRILE, DIBENZO COMPOUNDS, PERCHLORATE, THERMODYNAMIC PROPERTIES, CROWN ETHER, RARE EARTH