Effect of bilayer number on the photoluminescent property of TPE-based self-assembled film

• Published in: Chinese science bulletin Vol. 58; no. 22; pp. 2728 - 2732
• Main Authors: Chen, DiDi, Feng, Xiao, Gu, ShangZhi, Tong, Bin, Shi, JianBing, Zhi, JunGe, Dong, YuPing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.08.2013; Springer Berlin Heidelberg
• Subjects: Agglomeration; atomic absorption spectrometry; Chemistry/Food Science; Covalent bonds; Crosslinking; Decomposition reactions; Derivatives; Earth Sciences; Engineering; Fluorescence; fluorescence emission spectroscopy; Humanities and Social Sciences; hydrogen bonding; Letter; Life Sciences; Molecular structure; multidisciplinary; Photoluminescence; photolysis; Physics; Science; Science (multidisciplinary); ultraviolet radiation; 分子间相互作用; 原子力显微镜; 发光性能; 层数; 热塑性弹性体; 紫外线照射; 自组装膜; 荧光发射光谱; aggregation-induced emission; layer-by-layer self-assembled film; 1,4-benzenediamine diazonium salt; tetraphenylethylene
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-013-5943-7

Tetraphenylethylene （TPE） derivatives have been proved to be typical aggregation-induced emission （AIE） luminogens when they were aggregated in the free three-dimensional space. In order to reveal the effect of the dimensional degree on AIE property of TPEs, we utilized tetra（4-hydroxyphenyl）ethylene （TPE-4OH） and 1,4-benzenediamine diazonium salt （BD） to fabricate the ultra- thin fdms （TPE-4OH/BD LBL SA film） through layer-by-layer self-assembled technique. The interaction between TPE-4OH and BD in the films was converted from electrostatic force and hydrogen-bond to covalent bonds through photodecomposition of dia- zonium groups under UV irradiation. Fluorescence emission spectroscopy, UV-Vis absorption spectroscopy and atomic force microscope were carried out to evaluate the relationship between bilayer number and photoluminescence of the TPE-based self-assembled films. The experimental results showed that the TPE-based film with three bilayers only displayed AIE character, whereas the fluorescence of the film became randomly changed if the bilayer number was above three. It is supposed that the fluorescence property of the TPE-4OH/BD LBL SA film with limited molecular length in z-axis and infinite aggregation space in x- and y-axis is dominated by two competitive effects, one is the partial restriction of intramolecular rotation through short inter- molecular interactions in cross-linked structure of TPE-4OH/BD, and the other is deactivation of its excited state through unre- stricted intramolecular rotations or π-π interactions.