• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.291-295
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• 2006

The keto-enol tautomeric equilibrium constant, K, of ethyl acetoacetate in compressed and supercritical carbon dioxide was determined by using FT-IR (Fourier transform infrared) spectroscopy at three different temperatures. In order to investigate the effect of solvent density, the $CO_{2}$ pressure was systematically changed at a constant temperature. As the $CO_{2}$ density is increased, the amount of keto tautomer is increased, causing the K value to decrease. The modified lattice fluid hydrogen bonding theory has been applied to investigate the effect of density on the K.

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.385-389
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• 1988

Synthesis of 6-oxo-1,6-dihydro-1,2,4-triazine derivatives was tried. The model compounds of the possible tautomers were synthesized. The tautomeric equilibrium of 6-oxo-1,6, dihydro-1,2,4-triazine derivatives was determined by comparing their UV spectra and those of model compounds. 6-oxo-tautomer was exclusively detected in water and alcohol solutions without observation of the expected 6-hydroxy tautomers.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.3013-3016
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• 2010

• Textile Coloration and Finishing
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• v.23 no.3
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• pp.163-168
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• 2011

In this article, we synthesized an azo dye rotaxane containing bis(8-hydroxyquinoline) group and its polymeric metal complex with zinc. The azo dye rotaxane exhibits high pH sensitivity, solvatochromism and zinc (II) ion sensings in aqueous solution. These behaviors came from the tautomeric equilibrium between azo-hydrazone tautomers and the formation of extended conjugation. The structure of polymeric zinc complexed dye rotaxane was confirmed with NMR and FT-IR measurements. The existence of CD rings, provided by dye rotaxane formation, was found to be very beneficial in improving aqueous solubility of polymeric metal complex.