Table 1.

Absorption maxima of azo dyes 9 a–k, 15 a–h, and 20 a–c at thermal equilibrium (Δ), half‐lives of thermal Z→E isomerization and PSD after 365 nm and 452 nm irradiation.

	$\lambda \genfrac{}{}{0pt}{}{\Delta }{\max }$	t 1/2	E/Z [%][e]
	[nm][a]	[h][a]	@ 365 nm	@ 452 nm
9 a [b]	329	6	12/88	90/10
9 b [b]	332	8	10/90	86/14
9 c [c]	339	16	9/91	87/13
9 d [d]	345	21	9/91	88/12
9 e [d]	344	22	10/90	90/10
9 f [d]	346	21	10/90	91/9
9 g [d]	345	26	14/86	87/13
9 h [c]	337	0.7	14/86	91/9
9 i [c]	337	0.6	12/88	91/9
9 j [c]	330	0.6	29/71	93/7
9 k [c]	339	7	14/86	89/11
15 a [c]	325	178	31/69	94/6
15 b [c]	332	23	6/94	90/10
15 c [b]	329	319	11/89	86/14
15 d [b]	332	220	9/91	91/9
15 e [c]	326	254	40/60	89/11
15 f [d]	333	102	5/95	79/21
15 g [c]	355	50	25/75	89/11
15 h [c]	350	77	23/77	92/8
20 a [c]	352	33	4/96	80/20
20 b [c]	324	166	2/98	83/17
20 c [c]	340	63	14/86	85/15

[a] Solutions in DMSO/assay buffer (50 μm): [b] 5 % DMSO (v/v), [c] 50 % DMSO (v/v), [d] 90 % DMSO, (v/v); [e] PSD determined by HPLC analysis in MeOH/water mixtures applying isocratic conditions and evaporative light‐scattering detection (ELSD).