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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (21): 1962-1966. 上一篇    下一篇

研究论文

用微量热法测定稀土含硫有机配合物的比热容

帅琪1，高胜利*,1，陈三平1， 刘明艳2，胡荣祖1,3，史启祯1   

  1. (1西北大学化学系 陕西省物理无机化学重点实验室 西安 710069)
    (2绵阳中物热分析仪器有限公司 绵阳 621900)
    (3西安近代化学研究所 西安 710065)
  • 投稿日期:2005-01-12 修回日期:2005-07-12 发布日期:2010-12-10
  • 通讯作者: 高胜利

Determination of Specific Heat Capacity of Rare Earth Organic-sulfur Complexes by Microcalorimetry

SHUAI Qi1, GAO Sheng-Li*, 1, CHEN San-Ping1, LIU Ming-Yan2, HU Rong-Zua, c, SHI Qi-Zhen1   

  1. (1 Shaanxi Key Laboratory of Physico-inorganic Chemistry, Department of Chemistry, Northwest University, Xi'an 710069)
    (2 Mianyang Chinese Physics Thermal Analysis Instrument Co., Ltd, Mianyang 621900)
    (3 Research Institute of Xi'an Modern Chemistry, Xi'an 710065)
  • Received:2005-01-12 Revised:2005-07-12 Published:2010-12-10
  • Contact: SHUAI Qi

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被引次数

25 | 4

推导了用改进的RD496-III型微热量计测定固态物质比热容的计算式. 用Joule 效应确定了仪器在298.15 K时的量热常数和相对标准偏差分别为(63.901±0.030) μV•mW－1和0.08%, 用Peltier效应测定总不平衡热. 在该仪器上测定的两种标准物质(基准苯甲酸和α-Al2O3)比热容的计算值与文献值相差在0.4%以内. 用本法测定了13种固态配合物RE(PDC)3(phen) (RE＝La, Pr, Nd, Sm～Lu; PDC＝ )的比热容值, 总偏差在1.0%, 与稀土原子序数ZRE作图呈现“三分组现象”, 说明配合物中RE3＋与配体间的化学键有一定程度的共价性, 显示了稀土离子4f电子云的扩大效应.

关键词: 微量热法, 不平衡热, 稀土氯化物, 吡咯烷-N-二硫代甲酸铵, 邻二氮菲, 固态配合物, 比热容

A calculation formula for determining the specific heat capacity of solid with an improved RD496-III microcalorimeter was derived. The calorimetric constant and the relative standard deviation determined by use of Joule effect were (63.901±0.030) μV•mW－1 and 0.08% at 298.15 K, respectively, and the total disequilibrium heat has been measured by Peltier effect. The specific heat capacities of two standard samples (benchmark benzene carboxylic acid and α-Al2O3) were obtained with this microcalorimeter, and differences between their calculated values and their literature ones were less than 0.4%. Accordingly, the specific heat capacities of thirteen solid complexes RE(PDC)3(phen) (RE＝La, Pr, Nd, Sm～Lu; PDC＝ ) were also gained by the same method with their total deviations within 1.0%. These values were plotted against the atomic number of rare earth, which presents tripartite effect. It suggests existence of a certain amount of covalent character in the bond of RE3＋and ligands, according to Nephelauxetic effect of 4f electrons of rare earth ions.

Key words: microcalorimetry, disequilibrium heat, rare earth chloride, ammonium pyrrolidinyl-N-dithio- carboxylate, o-phenanthroline, solid complex, specific heat capacity