Université de Fribourg

Switching azonaphthols containing a side chain with limited flexibility. Part 1. Synthesis and tautomeric properties

Kurteva, Vanya B. ; Antonov, Liudmil ; Nedeltcheva, Daniela V. ; Crochet, Aurélien ; Fromm, Katharina M. ; Nikolova, Rositsa P. ; Shivachev, Boris L. ; Nikiforova, Maya S.

In: Dyes and Pigments, 2012, vol. 92, no. 3, p. 1266–1277

A series of azo dyes, possessing amide fragments with restricted flexibility tethered to 4-(phenyldiazenyl)naphthalen-1-ol, was obtained from 1-hydroxy-2-naphthoic acid by subsequent conversion to amides and diazo coupling. It was shown that the position of the tautomeric equilibrium in solution strongly depends on the solvent in both UV and NMR concentration scale. The compounds exist as...

Université de Fribourg

Solid state tautomerism in 2-((phenylimino)methyl)naphthalene-1-ol

Nedeltcheva, Daniela ; Kamounah, Fadhil S. ; Mirolo, Laurent ; Fromm, Katharina M. ; Antonov, Liudmil

In: Dyes and Pigments, 2009, vol. 83, no. 1, p. 121-126

The solid state tautomerism of 2-((phenylimino)methyl)naphthalene-1-ol was studied using X-ray measurements and absorption spectroscopy. In the solid state, the keto tautomer predominates. The observed shift in the equilibrium from the enol (dilute solution) to the keto (solid state) forms is explained by the formation of dye aggregates using ab initio quantum chemical calculations.