摘要
利用Langmuir-Blodgett(LB)技术对偶氮苯衍生物进行极性分子组装.紫外-可见吸收光谱显示该膜具有类H 聚集效应,利用红外线性二向色性光谱获得了分子的主要极性功能团的跃迁矩与膜表面法线的夹角,并结合其它光谱信息,给出了膜结构模型,就此对其优越的热释电性能做出解释.
Azobenzene derivative(AD)was organized to form Z type polar films byLangmuir-Blodgett technique.The UV-VIS spectra show that the spectra of chloro-form solution exhibited a broad band with λ(max)at 480nm,corresponding to the mon-omer,while the spectra observed on AD film exhibited a sharp peak at 380nm,corresponding to the absorption of the H-like aggregates.The 100nm blue-shift of theabsorption band from the monomer to the aggregates displays the existence of a highaggregate in the AD film.the linear dichroic FTIR spectra of AD film give infor- mations on the molecular orientation of several main transition moments.The resultsshow that the tilt angle of the axis of the hydrocarbon chain is 50°from the surfacenormal,and the tile angle of the azobenzene chromophore is 35°.The X-ray dif-fraction spectra display there are double long spacings of 3.5nm and 3.1nm respectivelyin the AD film.The further work of this system has been studied by temperature-changed UV-VIS spectra and infrared spectra.According to the results mentioned above,the structure may play an importantrole in the high pyroelectric property owing to a contribution of the intermolecularadditional dipole moments added to the spontaneous dipole moments.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1993年第5期597-603,共7页
Acta Physico-Chimica Sinica
基金
国家自然科学基金资助项目
关键词
LB膜
红外吸收光谱
聚集
LB film
Infrared spectra
UV-VIS spectra
Aggregation
