Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

Table 2

Substituent effect of dyes 4a–4f in DMSO, DMF, and ethanol.

Dyes	X	R	DMSO			DMF			Ethanol
			𝜆max	Δ𝜆^a	log𝜀	𝜆max	Δ𝜆^a	log𝜀	𝜆max	Δ𝜆^a	log𝜀
(a)	O	H	394.48	—	6.07	393.04	—	6.17	392.34	—	5.07
(b)	O	Cl	394.38	−0.10	6.25	392.85	−0.19	5.93	390.51	−1.83	5.68
(c)	O	F	396.26	+1.78	6.05	393.39	+0.35	6.17	392.41	+0.07	5.68
(d)	S	H	424.71	+30.23	5.40	423.04	+30.00	6.04	421.99	+29.65	5.69
(e)	S	Cl	425.12	+30.64	6.11	424.64	+31.60	6.17	423.25	+30.91	5.70
(f)	S	F	422.48	+28.00	6.11	421.57	+28.53	6.09	419.31	+26.97	6.09

^aRelative to dye (a).