Table 2.

Sensitivity to polarity^[a]

	Slope	Y-int.	Slope	Y-int.	R2
	cm−1/kcal mol−1	cm−1	-	kcal mol−1
1a	93.7	2548	0.268	7.29	0.99510
8a	63.8	5188	0.182	14.83	0.86159
1b	75.4	4290	0.216	12.27	0.84211
8b	79.5	4437	0.227	12.69	0.96922

^[a]Polarity sensitivity equals the slope of the linearized Stokes shift vs. E_T(30) plot. Values for 5-(thiophen-2-yl)-2dU 8a and 5-(fur-2-yl)-2dU 8b in cm⁻¹/kcal mol⁻¹ have been reported.^{[7, 25]} A unitless value for polarity sensitivity is obtained by conversion of the Stokes shift value from cm⁻¹ to kcal mol and replotting it as a function of the sample E_T(30) value (in kcal mol⁻¹). The adjusted R² represents the goodness of the linear fit.