A Way to Improve Luminescent Efficiency of Bis-Chalcone Derivatives

Table 2

Photophysical data for compounds 1a to 2b in solution state at room temperature.

Compound	/nm (ε/10^4 M^−1 cm^−1)	/nm		/ns	Stokes shift/cm^−1
1a	270 (0.970)	430	—	—	5500
	348 (2.228)
1b	278 (0.979)	432	—	—	3000
	383 (2.369)
2a	268 (1.519)	505		2.44 (15%)	10200
	333 (2.662)			4.04 (85%)
	421 (2.384)
2b	275 (1.385)	—	—	—	—
	350 (2.164)
	445 (2.576)

All the UV data was recorded in DCM solution. Not able to be determined due to very poor emission. Fluorescence quantum yield which was measured in DCM solution using an integrating sphere. Fluorescence quantum yield which was measured in acetonitrile solution using Coumarin 307 as a reference [26, 27]. Stokes shift was calculated based on abs  −   em.