Table 1. Absorption Maxima (λ_max) and Molar Extinction Coefficients (ε) in CH₃OH, Fluorescence Emission Maxima (λ_FL) and Quantum Yields for Fluorescence (Φ_FL) in CH₃OH, Quantum Yields for the Generation of Singlet Oxygen [Φ(¹O₂)] in CH₃OH, n-Octanol/Water Partition Coefficients (log P) for Thiorhodamines 15a–18a and Selenorhodamines 15b–18b^a.

compd	λmax, nm	ε, M–1 cm–1	λFL, nm	ΦFL	Φ(1O2)	log P
15ab	597	6.77 × 104	626	0.09 ± 0.01	<0.05	1.4
15b	609	7.18 × 104	636	0.009 ± 0.001	0.50 ± 0.03	2.26 ± 0.04
16ab	597	6.30 × 104	626	0.07 ± 0.01	<0.05	2.7
16b	608	9.78 × 104	635	0.008 ± 0.001	0.54 ± 0.03	2.41 ± 0.04
17ab	598	8.31 × 104	626	0.09 ± 0.01	<0.05	1.7
17b	609	8.73 × 104	634	0.009 ± 0.001	0.48 ± 0.03	2.23 ± 0.04
18ab	598	6.18 × 104	626	0.07 ± 0.01	<0.05	2.6
18b	608	8.11 × 104	634	0.008 ± 0.001	0.44 ± 0.03	1.61 ± 0.06

^aError limits are ±SD.

^bValues of λ_max, ε, and log P for 15a–18a are taken from ref (28).