Table 6.

Calculated ΔH°(c) (in kJ/mol) of Azo and Hydrazone Forms of some Azo Dyes.

Compound	Hydrazone Form ∆Hc calc	Azo Form ∆Hc calc	∆Hc exp	a	Ref.
4-Phenylazophenol	−6275.2	−6288.0	−6314.1	+ −	[528]
2-Phenylazophenol	−6272.3	−6287.2	-	+ −	[528]
4-Aminoazobenzene	−6651.1	−6603.1	−6617.4	+	[529]
2-Aminoazobenzene	−6648.4	−6602.4		+
1-Phenylazo-2-naphthol	−8145.8	−8185.1		+	[530,531]
4-Phenylazo-1-naphthol	−8148.5	−8185.4		+	[532]
1-Phenylazo-2-naphthylamine	−8533.8	−8500.3		+	[530,531]
4-Phenylazo-1-naphthylamine	−8524.6	−8503.0		+	[533]

^a Conformance with experimental data.