Table 3.

Optical properties of tC^O-containing RNA double strands.

Sequencea	λAbs,max [nm]b	λEm,max [nm]b	ΦF b,c	τ1(α1) [ns]b,d	τ2(α2) [ns]b,d	<τ>[ns]e	kr [107 s−1]f	knr [108 s−1]g
GG	373	453	0.22	4.9 (0.87)	1.9 (0.13)	4.5	4.9	1.7
UG	368	452	0.20	4.1 (0.88)	2.1 (0.12)	3.8	5.3	2.1
GU	373	460	0.22	4.8 (0.88)	2.2 (0.12)	4.5	4.9	1.7
AA	371	457	0.23	4.6 (0.89)	2.1 (0.11)	4.3	5.3	1.8
AU	370	459	0.23	4.4 (0.90)	2.0 (0.10)	4.2	5.5	1.8
CC	371	452	0.25	4.9 (0.91)	2.1 (0.09)	4.7	5.3	1.6
GUUU	370	456	0.22	4.5 (0.87)	2.2 (0.13)	4.2	5.2	1.9
GAUU	373	459	0.22	4.6 (0.88)	2.2 (0.12)	4.3	5.1	1.8
UUUG	371	456	0.23	4.3 (0.89)	1.9 (0.11)	4.1	5.6	1.9

^aSequences are named after the bases flanking tC^O (see Fig. 1b). Full sequences can be found in Supplementary Table S1. ^bMeasurements were performed in PBS buffer (100 mM Na⁺, pH 7.5). ^cFluorescence quantum yields are measured relative to the quantum yield of the potassium salt of the tC^O-monomer in water (Φ_F = 0.30)³¹. ^dThe amplitudes are indicated in parenthesis. ^eMean fluorescence lifetimes < τ >  = ∑α_iτ_i/∑α_i. ^fRadiative rate constant, k_r = Φ_F/<τ>. ^gNon-radiative rate constant, k_nr = k_r/Φ_F − k_r.