Table 1. UV–vis Absorption Maxima of E and Z Isomers (DMSO).

					λmax (nm) (ε × 104 M–1 cm–1)
					π–π*			n–π*
entry	compd	Ar	R1	R2	E	Z	Δλ	E	Z	Δλ
1	-17	phenyl	CH3	H	330	293	–37	421	436	15
2	-27	phenyl	CH3	CH3	335	296	–39	425	441	16
3	1a	phenyl	CF3	H	344 (1.27)	274	–70	424 (0.967)	440	16
4	1b	1-naphthyl	CH3	H	372 (1.95)	297	–75	390 (1.57)	448	55
5	1c	2-naphthyl	CH3	H	345 (2.57)	296	–49	380 (1.36)	443	63
6	1d	2-naphthyl	CF3	H	347 (1.85)	313	–34	384 (1.18)	430	46
7	1e	phenyl	CF3	CH3	320 (1.71)	284	–36	428 (0.695)	423	–5
8	1f	1-naphthyl	CH3	CH3	373 (1.87)	323	–50	398 (1.76)	450	52
9	1g	2-naphthyl	CH3	CH3	348 (2.22)	300	–48	378 (1.32)	447	69
10	1h	2-naphthyl	CF3	CH3	332 (1.72)	316	–16	400 (0.468)	434	34
11	1i	1-naphthyl	CH3	Ph	377 (1.64)	317	–60	400 (1.26)	451	51
12	1j	1-naphthyl	CH3	2,4-dinitrophenyl	380 (2.12)	321	–59	410 (1.45)	452	42
13	1k	1-naphthyl	CH3	4-tolyl	376 (1.98)	322	–54	404 (1.39)	455	51
14	1l	2-naphthyl	CH3	Ph	350 (2.35)	307	–43	380 (1.50)	450	70
15	1m	2-naphthyl	CH3	2,4-dinitrophenyl	344 (3.02)	312	–32	379 (2.28)	436	57
16	1n	2-naphthyl	CH3	4-tolyl	353 (2.75)	315	–40	380 (1.97)	450	70
17	1o	2-naphthyl	CH3	2-naphthyl	357 (3.15)	316	–41	381 (2.35)	446	65