Photophysical data of amino acids 13a–e.

Amino acid	Solvent	λ Abs a (nm)	ε (cm−1 M−1)	λ Em a (nm)	Φ F b	Brightness (cm−1 M−1)
13a	MeOH	342	16 500	350, 366	0.31	5120
	Water	341	8800	352, 366	0.28	2460
13b	MeOH	329	12 700	354	0.35	4450
	Water	331	12 100	357	0.43	5200
13c	MeOH	351	16 100	371, 388	0.76	12 240
	Water	362	10 900	377, 390	0.59	6430
13d	MeOH	363	22 300	393, 409	0.39	7250
	Water	361	19 600	419	0.37	4450
13e	MeOH	366	11 600	365, 378	0.06	700
	Water	348	14 000	380	0.24	3360

^aSpectra were recorded at 5 μM.

^bQuantum yields (Φ_F) were determined using anthracene and l-tryptophan as standards.