四氯合锌酸二(正十一烷基铵)晶体相变的Raman光谱

用Raman光谱研究了n-C~11H~23NH~3]~2ZnCl~4(简记为C~nZn)配合物的固-固相变。结果表明, 配合物产生的固-固相变主要与烷烃链的堆积结构和分子构象变化有关, 在T~cl=25℃的相变是由于烷烃链的侧向堆积和分子构象的有序到部分无序变化。在中间相, 分子链局部产生旁式构象。在T~c2=87℃的相变主要来源于烷烃链从部分构象有序到完全无序的变化, 高温相形成了构象完全无序相, 相应于烷烃链的"熔化"。

Raman spectroscopic study of crystal phase transition in bis(n- undecylammonium) tetrachlorozincate

The solid-solid phase transitions of C11H23NH3]2ZnCl4 complex were studied by Raman spectroscopy. The occurrence of the structural phase transitions are mainly related to the change of packing structure and mol. conformation of chains. The phase at Tcl = 25?is due to the change of packing state and conformation of chains from order to partial disorder. In the intermediate temperature phase, the chains contain partial gauche isomers. The phase transition at Tc2 = 87?arises from formation of total disorder of the alkyl chains. The high temperature phase leads to a "chain melting".