Table 2. Fluorescence Quantum Yields of the Investigated Compounds in Solvents of Different Polarity and Viscosity.

solvent	f(ε, n2)	η (cPs)	ϕF NPI-PTZ1	ϕF NPI-PTZ2	ϕF NPI-PTZ3	ϕF NPI-PTZ4	ϕF NPI-PTZ5
Tol	0.0242	0.59	0.51	0.87	0.70	0.66	0.75
Tol/An 50:50	0.143	1.16	0.20	1.27	1.16	0.47	0.73
CHCl3	0.293	0.58	0.017	0.92	0.90	0.12	0.76
EtAc	0.400	0.46	0.0075	0.90	0.93	0.099	0.73
THF	0.441	0.55	0.0079	0.87	0.89	0.067	0.89
DCM	0.474	0.45	0.0030	0.99	0.92	0.049	0.85
BCN	0.586	1.24	0.029	1.06	1.14	0.048	0.73
Ac	0.651	0.32	0.0015	0.50	0.90	0.047	0.68
DMF	0.664	0.92	0.0013	0.15	0.71	0.0084	0.44