Table 1. Photophysical Properties of Nucleosides 1a–f^a.

								Stokes shift
	substituent		absorption		emission		brightness	νabs – νem
compound	Y	solvent	λmax [nm]	εb	λmax [nm]	Φc	Φ × ε × 103	[cm–1]	[kcal/mol]
B(22)	(R = ribose) (X = S)	dioxane	335	13	415	0.80	10.4	6025	16.4
		methanol	334	11	433	0.50	5.5	7332	19.6
		water	332	11	455	0.20	2.2	8492	23.3
1a	F	dioxane	368	15.0	462	0.32	4.8	5504	15.7
		methanol	365	14.0	488	0.11	1.5	6867	19.6
		water	357	12.6	478	0.24	3.0	7140	20.4
1b	H	dioxane	371	9.7	461	0.30	2.9	5286	15.1
		methanol	367	8.9	488	0.16	1.4	6767	19.3
		water	356	9.6	478	0.21	2.0	7184	20.5
1c	Me	dioxane	375	14.6	468	0.38	5.6	5308	15.2
		methanol	372	14.0	499	0.07	1.0	6855	19.6
		water	360	13.9	490	0.12	1.7	7370	21.1
1d	MeO	dioxane	383	20.8	486	0.74	15.4	5534	15.8
		water	366	19.7	525	0.02	0.4	8275	23.7
1e	HO	dioxane	385	16.9	494	0.71	12.0	5695	16.3
		water	381	15.0	517	<0.01	<0.1	6944	19.8
1f	Me2N	dioxane	420	21.4	575	0.20	4.3	6428	18.4
		water	398	16.8	484	<0.01	<0.1	4464	12.8

^aAbsorption and steady-state emission spectroscopy studies were performed using samples prepared from a concentrated DMSO stock solution.²⁵

^bε in [× 10³ M^–1 cm^–1].

^cFluorescence standards: Coumarin 102 was used for 1a–e, and Coumarin 153 was used for 1f.