Molecular Dynamics Simulation of Aggregation-Induced Emissions Enhancement of Tetraphenylethylene In The Acetone/Water Mixture

• Main Authors: Yi-Kai Tseng, 曾奕剴
• Other Authors: Cheng-Lung Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/t7ehhv

碩士 === 國立中山大學 === 化學系研究所 === 103 === Most classical fluorophores that are conjugated and rigid planar molecules present excellent fluorescent quantum yield in dilute solutions, but quenches with the “formation of aggregates”, which is known as aggregation-caused quenching. In contrast, a group of fluorophores is non-emissive in dilute solutions but become highly luminescent when their molecules are aggregated in concentrated solution. The phenomenon is termed “aggregation-induced emission” . Among the AIE molecules, tetraphenylethene (TPE) have become the popular compound for the AIE property study recently because TPE enjoy the advantages of facile synthesis, efficient solid-state emission as well as aggregating and simple functionalization. In this study, we use molecular dynamics simulation to investigate TMTPE’s aggregation behavior in the acetone/water mixture with different concentration, and find that TMTPE molecules exactly aggregate in highly concentrated water solution. We analyze the RDF and nonbond energy between TMTPE/water and TMTPE/acetone, confirmed the solvent effect of acetone is better than water. We use quantum mechanics method to analyze the adsorption and emission spectrum of TMTPE and show bathochromic shift phenomenon. We study the structure and dihedral angles of TMTPE, and the result show the rotation of phenyl rings is limited by the solvent effects. This results is also consistent with the experiments mentioned in the literature.