Table 1.

Characteristics of papillon probes.

Cpd[a]	EtOAc 25 °C λ OP (ϵ)[b]  λ TP [c]	Φ fl [%][d]	σ (2) [GM][e]	EtOAc 25 °C λ e1/λ e2 [f]  I b/p [g]	H2O 25 °C λ e1/λ e2 [f]  I b/p [g]	DPPC 25 °C λ e1/λ e2 [f]	I b/p [g] (K x)[h]	DPPC 55 °C I b/p [g] (K x)[h]	DOPC 25 °C I b/p [g] (K x)[h]	DOPC 55 °C I b/p [g] (K x)[h]
1	354 (6.7)  700	14.4	4.0	465/592  0.2	459/– >20	467/587	3.4 (0.5)	0.7 (6.4)	1.7 (10.1)	0.7 (12.8)
2	378 (4.9)  750	5.0	1.7	510/614  0.1	502/– >20	517/595	2.2 (0.3)	0.6 (3.3)	1.0 (10.6)	0.5 (15.4)
3	334 (11.7) 692	4.2	2.5	435/580  0.3	449/– >20	495/570	3.1 (3.5)	0.4 (21.2)	0.7 (4.9)	0.3 (7.6)

[a] For compounds see Scheme 1. [b] Wavelength of one‐photon absorption maxima [nm] (extinction coefficient [mm ⁻¹ cm⁻¹]). [c] Wavelength of two‐photon absorption maxima [nm]. [d] Fluorescence quantum yield, determined using Coumarin 1 as a reference. [e] Two‐photon cross‐section, in Goeppert–Mayer (10⁻⁵⁰ cm⁴ s photon⁻¹); Supporting Information, Equation (S3). [f] Wavelength of the first (e1) and second emission maxima (e2), λ _ex at the maximum of the lowest energy band (from uncorrected spectra). [g] Fluorescence intensity ratio I _b/p=I _e1/I _e2. [h] Partition coefficient ×10⁶. DPPC=dipalmitoylphosphatidylcholine, DOPC=dioleoylphosphatidylcholine.