Gas-phase tautomerism in hydroxy azo dyes - from 4-phenylazo-1-phenol to 4-phenylazo-anthracen-1-ol.
The tautomeric constants of a series of azo dyes were estimated in the gas phase by using electron ionization mass spectrometry. It was shown that the relative amount of the keto tautomer increases from 4-phenylazo-1-phenol to 4-phenylazo-anthracen-1-ol, thus confirming the quantum-chemical predictions. The existence of the enol tautomer of 4-phenylazo-anthracen-1-ol is shown for the first time by mass spectrometry in the gas phase. This finding is supported by flash photolysis measurements in solution.
Nedeltcheva
Daniela
D
Institute of Organic Chemistry with Centre of Phytochemistry, Acad. G.Bonchev str., bl.9, Sofia 1113, Bulgaria. dantonova@orgchm.bas.bg
Kurteva
Vanya
V
Topalova
Ivanka
I