Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

Table 4 Regression fits to the solvatochromic parameters (Eq. 1 )

No.	Substituent	ν₀(10³cm^–1)	s(10³cm^–1)	b(10³cm^–1)	a(10³cm^–1)	r ^a	s ^b	F ^c	Solvents used in the calculation^d
1	H	21.92	1.81	0.80	0.52	0.9789	0.078	46	1–11
1	H	(±0.180)	(±0.240)	(±0.170)	(±0.100)
2	OH	21.34	−0.53	−0.86	−0.20	0.9417	0.099	21	2–13
2	OH	(±0.155)	(±0.269)	(±0.280)	(±0.191)
3	OCH₃	23.02	−0.66	0.22	−0.31	0.9614	0.037	24	1–10,13
3	OCH₃	(±0.159)	(±0.089)	(±0.078)	(±0.104)
4	CH₃	23.02	−0.44	−0.19	−0.24	0.8128	0.099	5	1–10,12,13
4	CH₃	(±0.159)	(±0.222)	(±0.197)	(±0.118)
5	Cl	21.28	2.57	0.61	−0.31	0.9802	0.081	57	1–11
5	Cl	(±0.183)	(±0.246)	(±0.176)	(±0.098)
6	Br	21.61	2.11	0.38	−0.27	0.9703	0.085	38	1–11
6	Br	(±0.194)	(±0.260)	(±0.186)	(±0.104)
7	I	21.39	2.01	0.50	−0.25	0.9812	0.067	52	1–9,11
7	I	(±0.164)	(±0.210)	(±0.147)	(±0.083)
8	F	21.14	3.02	0.79	−0.43	0.9738	0.113	43	1–11
8	F	(±0.256)	(±0.344)	(±0.246)	(±0.138)
9	CN	24.50	−1.21	−0.51	0.10	0.9862	0.042	71	1–7,10–12
9	CN	(±0.102)	(±0.114)	(±0.097)	(±0.051)
10	COOH	24.58	−1.25	−0.57	0.09	0.9823	0.046	64	1–7, 9–12
10	COOH	(±0.097)	(±0.121)	(±0.098)	(±0.055)
11	COCH₃	23.73	−0.92	−0.23	−0.16	0.9878	0.027	94	1−12
11	COCH₃	(±0.050)	(±0.062)	(±0.057)	(±0.033)
12	NO₂	27.02	−5.14	−1.71	0.47	0.9735	0.176	42	1–7,9,10,12,13
		(±0.398)	(±0.533)	(±0.382)	(±0.214)

ISSN: 2661-801X