Spectroscopic and Crystallographic Study of Phase Transitions in Zn Bidimensional Complexes
作者:
M. Rey-lafon,
C. Lartigue-bourdeau,
Th. Maris,
M. Khechoubi,
N.B. Chanh,
期刊:
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals
(Taylor Available online 1995)
卷期:
Volume 269,
issue 1
页码: 55-73
ISSN:1058-725X
年代: 1995
DOI:10.1080/10587259508037321
出版商: Taylor & Francis Group
关键词: bilayered compounds;order-disorder phase transitions;molecular conformation;X-ray difraction;calorimetry;vibrational analysis
数据来源: Taylor
摘要:
The solid phases which appear when heating crystalline bisn-decyl andn-dodecyl ammonium tetra-chlorozincates (C10Zn and C12Zn for short) were studied using differential scanning calorimetry, X-ray diffraction and infrared and Raman spectroscopies. The unit-cell parameters of the different phases were determined. For C10Zn as well as for C12Zn, the room temperature stable phase is a well-ordered interdigitated layer structure with chains in all-trans conformation. A great mobility of the chains is observed when raising temperature within the phase, but the formation of specific sequences of bonds, mainly kinksgt2n-1g′ and end gauche forms, abruptly occurs at the first transition temperature at the same time as the cell parameters change. The consecutive increase in the chain diameter induces a partial disinterdigitation. A second phase change at higher temperature leads to a highly disordered form in which only the inorganic matrix keeps a bidimensional crystallographic organization, before reaching the isotropic phase.
点击下载:
PDF (1051KB)
返 回