通过傅里叶变换红外光谱（FT-IR）和二维红外相关光谱对聚酰胺-胺（PAMAM）树枝状大分子进行表征。

Characterization by fourier transform infrared spectroscopy (FT-IR) and 2D IR correlation spectroscopy of PAMAM dendrimer.

作者信息

Popescu Maria-Cristina, Filip Daniela, Vasile Cornelia, Cruz C, Rueff J M, Marcos Mercedes, Serrano J L, Singurel Gh

机构信息

Petru Poni Institute of Macromolecular Chemistry, 41A Alley Gr. Ghica Voda, 700487-Iasi, Romania.

出版信息

J Phys Chem B. 2006 Jul 27;110(29):14198-211. doi: 10.1021/jp061311k.

DOI:10.1021/jp061311k

PMID:16854120

Abstract

FT-IR and 2D correlation spectroscopy were employed to study the microstructural changes occurring during phase transitions of a liquid crystal poly(amidoamine) codendrimer (PAMAM (L1)16(L2)16) generation 3, functionalized on the terminal groups by one-chain promesogenic calamitic units (4-(4'-decyloxybenzoyloxy)salicylaldehyde (L1)) and two-chain promesogenic calamitic units (4-(3',4'-didecyloxybenzoyloxy)salicylaldehyde (L2)). Spectral modifications associated with molecular conformation rearrangements allowing for molecular shape change on going from a liquid-crystalline organization to another were found. The transition temperatures were calculated, and they are in good agreement with the DSC data. Spectral analysis gives evidence of the LC phase transitions and to an additional transition associated with the existence of conformers. Various types of hydrogen bonding have been established.

摘要

采用傅里叶变换红外光谱（FT-IR）和二维相关光谱研究了第三代液晶聚（酰胺胺）树枝状大分子（PAMAM (L1)16(L2)16）在相变过程中发生的微观结构变化，该树枝状大分子的端基通过单链前介晶棒状单元（4-(4'-癸氧基苯甲酰氧基)水杨醛（L1））和双链前介晶棒状单元（4-(3',4'-二癸氧基苯甲酰氧基)水杨醛（L2））进行功能化。发现了与分子构象重排相关的光谱变化，这些变化使得分子在从一种液晶组织转变为另一种液晶组织时能够改变形状。计算了转变温度，其与差示扫描量热法（DSC）数据吻合良好。光谱分析证明了液晶相转变以及与构象异构体存在相关的额外转变。已经确定了各种类型的氢键。