Optical property investigations of coumarin and indene diketone structure dyes: Experiment and calculation

The fluorescence coumarin derivatives were synthesised by an efficient one-pot, three-component reaction in 80–90% yields. The optical properties of these coumarin derivatives (4a-4d), such as the influence of different solvent to the fluorescence intensity and absorption intensity, and the influence of different substituent groups and the concentration of the solution are investigated. The results show that the fluorescence intensity of the compounds are the largest in the DMF（N,N-dimethyllformamide). Specifically speaking, the absorption spectrum is at approximately 308 nm, the fluorescence spectrum is at nearly 435 nm in the DMF, the Stocks shift approaches127 nm. In our case the fluorescence intensity decreases with the increase of the concentration of the solution, which is called concentration quenching. Additionally, the affection of solvent was also confirmed by TD-DFT (Time-dependent density functional theory)calculations.