[en] The method of isothermal saturation has been used for studying solvatation at 22+-1 deg in the following systems: RCl₃-Solv-C₆H₆, R₃Cl-Solv-C₄H₈O₂, LaBr₃-Solv-C₄H₈O₂, where R=Y, La; Solv=CH₃OH, C₂H₅OH, C-C₃H₇OH. The solvate numbers have been established and equilibrium constants of the reactions of RCl₃ and LaBr₃ solvatation have been calculated. It has been shown that the greater the cation radius, the weaker the strength of the solvatocomplex. The following crystallosolvates have been obtained: YCl₃x3CH₃OH; YCl₃x2C₂H₅OH; YCl₃xH-C₃H₇OH; LaCl₃xCH₃OH; LaBr₃x2CH₃OH; LaBr₃x2H-C₃H₇OH. Upon heating in air they decompose with the formation of oxychloride. Infrared-spectra have revealed coordination of the alcohol molecule near the metal ion