Table 2.

Switching kinetics of the photochromic compounds (in acetonitrile solution).

	αa [%]	φOF→CFb	φCF→OFc	φon-switching/φoff-switching	Nphd
AsTh1	36	0.13	0.14	1.1e	<1
SyTh1	71	0.16	0.07	0.4e	<1
AsTh2	28	0.03	0.15	5.0e	3
SyTh2	71	0.04	0.06	1.5e	2
AsOTh1	>98	9.0 · 10−2	1.6 · 10−3	56f	225
SyOTh1	>98	2.4 · 10−2	8.8 · 10−5	273f	5230
AsOTh2	>98	7.6 · 10−5	–g	–	–
SyOTh2	>99	1.9 · 10−4	–g	–	–
3h [16]	53i	0.39i	0.35j	–	–
6 [4]	31	0.24i	0.25k	–	–

^aConversion into the CF in the PSS (365 nm). ^bIrradiation at 365 nm. ^cIrradiation at 530 nm. ^dThe number of average emitted photons before off-switching is proportional to the ratio of fluorescence quantum yield and off-switching quantum yield; the off-switching quantum yield is φ_OF→CF for nonoxidized and φ_CF→OF for oxidized compounds. ^eRatio of cycloreversion and cyclization. ^fRatio of cyclization and cycloreversion. ^gIrreversible bleaching overcame the cycloreversion reaction. ^hIn hexane. ⁱIrradiation at 313 nm. ^jIrradiation at 517 nm. ^kIrradiation at 405 nm.