STUDIES ON PHASE-EQUILIBRIUM OF LACL3-CEN TER-DOT-3H(2)O-18C6-C2H5OH SYSTEM AT 25-DEGREES-C AND SYNTHESIS AND CHARACTERIZATION OF SOLID COORDINATION-COMPOUNDS

The solubilities of LaCl3 . 3H(2)O-18C6-C2H5OH ternary system at 25 de grees C were investigated by a semimicro method of phase equilibrium s tudy, and the refractive indexes of saturated solutions were determine d. The results indicate that there are three kinds of complexes formed in this system, namely, 3LaCl(3) . 18C6 . 9H(2)O . C2H5OH, 2LaCl(3) . 18C6 . 6H(2)O . C2H5OH and LaCl3 . 18C6 . 3H(2)O. The behavior of wat er in this system during the equilibrium was examined and the results show that the mole ratio, H2O/LaCl3, is always 3 : 1, no matter it is in liquid or solid phase. Three solid complexes were prepared and char acterized by IR spectra, DTG, TG and DSC. According to the DSC, the en thalpies of some steps during the decomposition were obtained for thes e three complexes.