Molecular Origins of Dye Aggregation and Complex Formation Effects in Coumarin 343
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- 作者：Xiaogang Liu ; Jacqueline M. Cole ; Kian Sing Low
- 刊名：The Journal of Physical Chemistry C
- 出版年：2013
- 出版时间：July 18, 2013
- 年：2013
- 卷：117
- 期：28
- 页码：14723-14730
- 全文大小：371K
- 年卷期：v.117,no.28(July 18, 2013)
- ISSN：1932-7455
文摘
Solvent effects have a significant impact upon the optoelectronic properties of coumarin 343, which are mainly exploited in the solution phase for a diverse range of applications, including lasers and dye-sensitized solar cells. The influence of solvation on the structure鈥損roperty relationships for coumarin 343 are analyzed herein using (time-dependent) density functional theory (DFT/TD-DFT) based quantum calculations, in conjunction with UV鈥搗is absorption and 1H NMR spectroscopic measurements. Specifically, these solvent effects on the peak UV鈥搗is absorption wavelengths (位maxabs), and molecular geometry changes of coumarin 343 are investigated. Coumarin 343 is shown to be prone to dye aggregation; its different molecular aggregation phases, UV鈥搗is absorption profiles, and formation mechanisms are discussed using three representative solvents: cyclohexane [nonpolar and non-hydrogen bonding (NHB)], benzene (polar and nearly NHB), and ethanol (polar and hydrogen-bond accepting/donating). It is also demonstrated that the intramolecular hydrogen bond in coumarin 343 can be 鈥渙pened up鈥?in hydrogen-bond accepting solvents. Furthermore, this study elucidates the solvent effects on the molecular conformations of coumarin 343. The much deeper understanding of the molecular aggregation and complex formation mechanisms in coumarin 343 provides key building blocks for the knowledge-based molecular design of coumarin dyes with antiaggregation characteristics. The associated molecular engineering prospects for these dyes stand to improve device performance for optoelectronic applications.