Spectral characteristics of the 2-(diethylamino)-4-(1-ethylpropyl)-6-phenyl-benzene-1,3-dicarbonitrile derivatives studied in acetonitrile.

Acronym	λ max-ab a [nm]	ε @ λmax-aba [dm3 mol−1 cm−1]	ε @ 365 nm [dm3 mol−1 cm−1]	ε @ 405 nm [dm3 mol−1 cm−1]	ϕ f
BI-PH	358	2120	2050	370	0.045
BI-PH-CH3	357	1770	1680	190	0.050
BI-PH-O-CH3	349	1750	1590	260	0.041
BI-PH-CN	369	1370	1360	610	0.059
BI-PH-SO2-CH3	364	1420	1400	440	0.044
BI-PH-S-CH3	310	8120	1720	230	0.043
BI-PH-CF3	361	1620	1600	440	0.052
BI-1-NPH	357	830	730	70	0.050
BI-2-NPH	365	1830	1830	310	0.012
BI-1-AN	366	4240	4220	1050	0.158

^aFor the longest wavelength absorption band.