Acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-Ones: Molecular Switches with Varying Migrants and Substituents

Table 1

Spectral characteristics (long-wave length maxima) of ( 2)–( 8) in acetonitrile solutions and quantum yields (𝜑) of the A→B rearrangement.

Comp.	Absorption of (Z -A), 𝜆max (nm),	𝜑A→B	Absorption of (S -trans -B), 𝜆max (nm),
	(𝜀×10^−4, dm^3 mol^-1 cm^-1)		(𝜀×10^−4, dm^3 mol^-1 cm^-1)
2*	424 (1.10)	—	—
3a*	427 (1.04)	0.60	338 (2.32)
3b	425 (1.24)	0.63	339 (2.27)
4a	427 (1.28)	0.62	342 (2.24)
4b*	422 (1.17)	0.41	333 (0.81)
4c*	423 (1.36)	0.52	340 (2.14)
7a	430 (1.42)	0.48	342 (2.19)
7b	430 (1.32)	0.40	343 (2.09)
7c	431 (1.34)	0.002	—
8a	430 (1.41)	—	—
8b	425 (1.22)	0.50	353 (2.20)
8c	425 (1.26)	0.50	345 (2.25)
8d	425 (1.23)	0.47	350 (2.56)
8e	424 (1.22)	0.51	347 (2.51)
8f	424 (1.23)	0.49	347 (2.51)
8g	424 (1.19)	0.41	342 (2.30)
8h	424 (1.13)	0.48	346 (2.52)
8i	424 (1.29)	0.45	350 (2.74)
8j	424 (1.14)	0.29	356 (2.65)
5	—	—	338 (2.36)
6	—	—	342 (2.14)

*See [9].