La（NCS）_3·4．5H_2O和B_15C_5在乙醇中的相平衡及热化学研究

Studies on Phase Equilibrium and Thermochemistry of La(NCS)3·4.5H2O with Bl5C5 in C2H5OH

采用半微量相平衡方法测定了三元体系Ｌａ（ＮＣＳ）_３·４．５Ｈ_２Ｏ－Ｂ_１５Ｃ_５－Ｃ_２Ｈ_５ＯＨ在２９８．１５Ｋ的溶解度，测定了各饱和溶液的折光率。结果表明：该体系中生成了一种化学计量的配合物Ｌａ（ＮＣＳ）_３·Ｂ_ｌ５Ｃ_５·４．５Ｈ_２Ｏ（Ｉ）。制备了固态配合物，用ＩＲ、ＴＧ、ＤＴＧ、ＤＳＣ及电导对其进行了表征。采用量热法测定了２９８．１５Ｋ时Ｂ_１５Ｃ_５和（Ｉ）在Ｃ_２Ｈ_５ＯＨ中的积分溶解热以及Ｌａ（ＮＣＳ）_３·４．５Ｈ_２Ｏ在Ｂ_１５Ｃ_５－Ｃ_２Ｈ_５ＯＨ溶液中的热效应，依据本文所设计的热化学反应，求得了配合物（Ｉ）的标准生成焓。

The solubilities of the ternary system, La(NCS) 3·4.5H2O-B15C5-C2H5OH, were investigated at 298.15 K by a semimicro method for study of phase equilibrium and the refractive indexes of saturated solutions were determined.A stoichiometrical coordination compound, La( NCS)3·B15C5·4.5H2O(I), formed in the system.The solid coordination compound was prepared and characterized by IR , TG , DTG ,DSC and conductivity measurement.The integral heats of solution of La(NCS)3·4. 5H2O in B15C5-C2H5OH solution,the complex(I) and B15C5 in C2H5OH were measured calorimetrically at 298.15 K. By means of thermochemical reactions suggested in this paper, the standard molar enthalpy of formation for(I) was obtained.