60305-61-5Relevant articles and documents
Effect of Hydroxide Ion on the Cis-Trans Thermal Isomerization of Azobenzene Derivatives
Sanchez, Ana M.,Rossi, Rita H. de
, p. 2974 - 2976 (1995)
Azobenzenes can be photochemically transformed from the trans (E) form, which is thermodynamically more stable, to the cis (Z) form.In the dark, the latter reverts to the former.We report here a kinetic study of the thermal isomerization of methyl orange (1), 4-(dimethylamino)-4'-methoxyazobenzene (2), and naphthalene-1-azo-(4'-(dimethylamino)benzene) (3) in water or in water/cosolvent solution measured at different hydroxide ion concentrations.It was found that the reaction is strongly dependent on the hydroxide ion concentration.The observed rate constant for 2 changes from 1.43E-2 s-1 at NaOH (1.0E-3 M) to 7.7E-4 s-1 at NaOH (0.10 M).These results can be interpreted in terms of the isomerization rate constant of the protonated substrates which is at least 1E8 times faster than that of the neutral compound.
Synthesis of methyl orange using ionic liquids
Astolfi, Danette L.,Mayville, Francis C.
, p. 9223 - 9224 (2007/10/03)
Two ionic liquids were synthesized, each system consisting of the 1-hexyl-3-methylimidazolium ion ([hmim]+) as the cation and either hexafluorophosphate ([PF6]-), or perchlorate ([ClO4]-) as the anions. This study involves
On the mechanism of the acid/base-catalyzed thermal cis-trans isomerization of methyl orange
Sanchez, Ana M.,Barra, Monica,De Rossi, Rita H.
, p. 1604 - 1609 (2007/10/03)
The thermal cis-trans isomerization of methyl orange (i.e., sodium 4-[4′-(dimethylammo)phenylazo]-benzenesulfonate) in acidic aqueous solutions has been investigated by means of laser-flash photolysis techniques. The thermal cis-trans isomerization is fou
