(东北大学 理学院， 沈阳 110004)
摘 要: 溴化稀土在948K以下时蒸气压极小， 以至于无法测出。 研究显示，可能是由于生成气态配合物NdyAlxBr3（x+y），溴化钕与溴化铝在600K以上共热时，溴化钕的表观蒸气压大幅度提高。 平衡实验结果表明， 在温度为629~805K和压力为0.015~0.19MPa时， NdAl3Br12 是惟一的稳定气态配合物。 反应式NdBr3(s)+(3/2) Al2Br6(g)=NdAl3Br12(g)的平衡常数由骤冷实验结果计算。假设ΔCp-=0J·mol-1·K-1， 该反应的焓变和熵变分别为ΔH298-=25.5±2.0kJ/mol和ΔS298-=-2.6±3.0J·mol-1·K-1。
关键字: 稀土； NdAl3Br12；气态配合物； 骤冷法； 热力学性质
（School of Sciences, Northeastern University,
Shenyang 110004, China）
Abstract: When temperature is below 948K, the vapour pressure of rare earth bromides is immeasurably small. But experiments show that, when it heat together with aluminum bromide at above 600K, the apparent vapour pressure of neodymium bromide may obviously increase. That may be caused by the formation of vapour complexes NdyAlxBr3（x+y）. Equilibrated quenching experimental results for the (NdBr3+AlBr3) system show that the NdAl3Br12 complex is the sole predominant vapour complex roughly at the temperature of 629～805K and under pressure of 0.015～0.19MPa. Changes in thermodynamic properties of the reaction were calculated from the reaction equilibrium constants. The results show that ΔH298- is 25.5±2.0kJ·mol-1 and ΔS298- is -2.6±3.0J·mol-1·K-1 with the assumption of ΔC-p is 0J·mol-1·K-1.
Key words: rare earth; NdAl3Br12; vapor complex; quenching; thermodynamics
