1417721-45-9Relevant articles and documents
Role of tautomerism and solvatochromism in UV-VIS spectra of arylhydrazones of β-diketones
Kuznik, Wojciech,Kopylovich, Maximilian N.,Amanullayeva, Gunel I.,Pombeiro, Armando J.L.,Reshak, Ali H.,Mahmudov, Kamran T.,Kityk
, p. 11 - 15 (2012)
New arylhydrazones of β-diketones, 5-chloro-3-(2-(1-ethoxy-1,3- dioxobutan-2-ylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (1), 3-(2-(1-ethoxy-1,3-dioxobutan-2-ylidene)hydrazinyl)-2-hydroxy-5- nitrobenzenesulfonic acid (2), and 3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene) hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonic acid (3), have been synthesized and characterized by IR, 1H and 13C NMR spectroscopies and elemental analysis. 3 and known 5-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene) hydrazinyl)-4-hydroxybenzene-1,3-disulfonic acid (4) exist in DMSO solution exclusively in the hydrazone form, while 1 and 2 exist in DMSO and H 2O solutions as a mixture of enol-azo and hydrazone tautomeric forms, in ratios dependent on the solvent polarity and inductive effect of the substituents. DFT and TDDFT approaches were applied for simulations of experimental UV-VIS absorption spectra of the studied compounds, taking into account solvatochromic as well as tautomeric effect. The performed simulations have established a correlation of substantial experimental 120 nm red shift of the enol-azo form with respect to hydrazone with HOMO and LUMO orbitals' delocalization.
