摘要
用DSC和TG研究了(n-C_nH_(2n+1)NH_3)_2CuCl_4(n=7-12)(记为C_nM)配合物的热稳定性和固-固相变。由红外光谱讨论了C_9Cu三个相的性质。发现C_nM的热稳定性呈奇偶效应;主相变峰温随链长增长而升高;相变总ΔH和ΔS也随链增长而加大;当n≤9时,高温相为部分无序相;而n≤10时,高温相为构象无序相。C_9Cu的主相变主要源自链间堆积结构变化。而在307.7K的相变主要与烃链有序-无序变化有关。
The thermal stability and the solid-solid phase transitions in the [n-C_nH_(2n+1)NH_3]_2CuCl_4 compounds with n=7-12 have been studied by DSC and TG methods.Comparision with C_nZn compounds was made. The nature of three phases of C_9Cuhas been discussed in terms of infrared spectroscopy and the assignment of thephase transitions has been given. The thermal stability of C_nCu is lower than that ofC_nZn and presents an obvious odd-even effect. All of these compounds exhibit twosolid-solid phase transitions in the temperature range of 248-337 K. The peak tempe-rature of phase transitions changes regularly.The peak temperature of the main phasetransition increases with the chain length. The total transition enthalpies and entropies increase with increasing chain length. When n≤9, the high temperature phase ex-ists in a partial disorder state. When n≥10, the high temperature phase exists in aconformational disorder state. The main phase transition and the phase transition at307.7 K of C_9Cu may mainly arise from the change of the packing structure and thechange of the partial conformational order-disorder of alkyl chain, respectively.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1992年第6期783-788,共6页
Acta Physico-Chimica Sinica
关键词
热分析
红外光谱
相变
铜络合物
Thermalanalysis
Infrared spectroscopy
Phase transition
Order-disorder
Thermal stability