TY  - JOUR
AU  - Verbić, Tatjana
AU  - Drakulić, Branko J.
AU  - Zloh, Mire
AU  - Pecelj, Jovana R.
AU  - Popović, Gordana V.
AU  - Juranić, Ivan O.
PY  - 2007
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/902
AB  - The protolytic equilibria of 13 4-aryl-2,4-dioxobutanoic acids (ADKs) were spectrophotometrically studied in aqueous solutions in the pH range 1-9 at 25 +/- 1 degrees C and an ionic strength of 0.1 mol 1(-1) (NaCl), with the exception of the 4-OH-derivative which was also potentiometrically studied in the pH range 7-10 at 25 +/- 1 degrees C and an ionic strength of 0.1 mol 1(-1) (NaCl). In solution, the compounds simultaneously exist in one diketo and two enolic forms; therefore, the determined acidity constants (pK(al) 1.87-2.29. pK(a2) 6.63-8.13 and pK(a3)(4-OH-) 9.52) represent system macro constants. The H-1-NMR spectrum of the parent compound (4-phenyl-2,4-dioxobutanoic acid) (25 degrees C, pD 5.0) proved the existence of all tautomeric forms. Using the extended Hammett relation, the determined pK(a) values were correlated with literature sigma values. The predicted pK(a) values were in fair accordance with the experimentally observed ones. Molecular, monoanionic and dianionic forms of the parent compound were optimized by the semi-empirical molecular orbital PM6 method using the implicit water solvation model (COSMO). The obtained geometries were used to explain the quality of the LEER models.
AB  - Protolitičke ravnoteže 13 jedinjenja iz klase 4-aril-2,4-dioksobutanskih kiselina (ADK) spektrofotometrijski su proučavane u vodenim rastvorima u pH intervalu 1-9 pri temperaturi 25±1 °C i jonskoj jačini rastvora 0.1 mol l-1 (NaCl), sa izuzetkom 4-OH-derivata koji je proučavan i potenciometrijski u pH intervalu 7-10 pri istim uslovima. Kako ADK u vodenom rastvoru podležu keto-enolnoj tautomeriji i istovremeno postoje u diketo i dva enolna oblika, to određene kiselinske konstante (pKa1 1.87-2.29, pKa2 6.63-8.13 i pKa3(4-OH-) 9.52) predstavljaju makro konstante za dati sistem. 1H-NMR spektar osnovne supstance (4-fenil-2,4-dioksobutanska kiselina) (25 °C, pD 5.0) potvrđuje prisustvo svih tautomernih oblika. Upotrebom proširene Hametove korelacije, određene pKa vrednosti korelisane su sa literaturnim σ vrednostima. Predviđene pKa vrednosti dobro se slažu sa eksperimentalno dobijenim. Molekulski, monoanjonski i dianjonski oblici osnovne supstance su optimizovani semiempirijskom molekulsko-orbitalnom PM6 metodom sa implicitnim modelom solvatacije u vodi (COSMO). Dobijene geometrije su upotrebljene za objašnjenje kvaliteta LFER modela.
PB  - Serbian Chemical Soc, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - An LFER study of the protolytic equililbria of 4-aryl-2,4-dioxolbutanoic acids in aqueous solutions
T1  - Linearne korelacije slobodne energije (LFER) protolitičkih ravnoteža 4-aril-2,4-dioksobutanskih kiselina u vodenim rastvorima
VL  - 72
IS  - 12
SP  - 1201
EP  - 1216
DO  - 10.2298/JSC0712201V
ER  - 

@article{
author = "Verbić, Tatjana and Drakulić, Branko J. and Zloh, Mire and Pecelj, Jovana R. and Popović, Gordana V. and Juranić, Ivan O.",
year = "2007",
abstract = "The protolytic equilibria of 13 4-aryl-2,4-dioxobutanoic acids (ADKs) were spectrophotometrically studied in aqueous solutions in the pH range 1-9 at 25 +/- 1 degrees C and an ionic strength of 0.1 mol 1(-1) (NaCl), with the exception of the 4-OH-derivative which was also potentiometrically studied in the pH range 7-10 at 25 +/- 1 degrees C and an ionic strength of 0.1 mol 1(-1) (NaCl). In solution, the compounds simultaneously exist in one diketo and two enolic forms; therefore, the determined acidity constants (pK(al) 1.87-2.29. pK(a2) 6.63-8.13 and pK(a3)(4-OH-) 9.52) represent system macro constants. The H-1-NMR spectrum of the parent compound (4-phenyl-2,4-dioxobutanoic acid) (25 degrees C, pD 5.0) proved the existence of all tautomeric forms. Using the extended Hammett relation, the determined pK(a) values were correlated with literature sigma values. The predicted pK(a) values were in fair accordance with the experimentally observed ones. Molecular, monoanionic and dianionic forms of the parent compound were optimized by the semi-empirical molecular orbital PM6 method using the implicit water solvation model (COSMO). The obtained geometries were used to explain the quality of the LEER models., Protolitičke ravnoteže 13 jedinjenja iz klase 4-aril-2,4-dioksobutanskih kiselina (ADK) spektrofotometrijski su proučavane u vodenim rastvorima u pH intervalu 1-9 pri temperaturi 25±1 °C i jonskoj jačini rastvora 0.1 mol l-1 (NaCl), sa izuzetkom 4-OH-derivata koji je proučavan i potenciometrijski u pH intervalu 7-10 pri istim uslovima. Kako ADK u vodenom rastvoru podležu keto-enolnoj tautomeriji i istovremeno postoje u diketo i dva enolna oblika, to određene kiselinske konstante (pKa1 1.87-2.29, pKa2 6.63-8.13 i pKa3(4-OH-) 9.52) predstavljaju makro konstante za dati sistem. 1H-NMR spektar osnovne supstance (4-fenil-2,4-dioksobutanska kiselina) (25 °C, pD 5.0) potvrđuje prisustvo svih tautomernih oblika. Upotrebom proširene Hametove korelacije, određene pKa vrednosti korelisane su sa literaturnim σ vrednostima. Predviđene pKa vrednosti dobro se slažu sa eksperimentalno dobijenim. Molekulski, monoanjonski i dianjonski oblici osnovne supstance su optimizovani semiempirijskom molekulsko-orbitalnom PM6 metodom sa implicitnim modelom solvatacije u vodi (COSMO). Dobijene geometrije su upotrebljene za objašnjenje kvaliteta LFER modela.",
publisher = "Serbian Chemical Soc, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "An LFER study of the protolytic equililbria of 4-aryl-2,4-dioxolbutanoic acids in aqueous solutions, Linearne korelacije slobodne energije (LFER) protolitičkih ravnoteža 4-aril-2,4-dioksobutanskih kiselina u vodenim rastvorima",
volume = "72",
number = "12",
pages = "1201-1216",
doi = "10.2298/JSC0712201V"
}

Verbić, T., Drakulić, B. J., Zloh, M., Pecelj, J. R., Popović, G. V.,& Juranić, I. O.. (2007). An LFER study of the protolytic equililbria of 4-aryl-2,4-dioxolbutanoic acids in aqueous solutions. in Journal of the Serbian Chemical Society
Serbian Chemical Soc, Belgrade., 72(12), 1201-1216.
https://doi.org/10.2298/JSC0712201V

Verbić T, Drakulić BJ, Zloh M, Pecelj JR, Popović GV, Juranić IO. An LFER study of the protolytic equililbria of 4-aryl-2,4-dioxolbutanoic acids in aqueous solutions. in Journal of the Serbian Chemical Society. 2007;72(12):1201-1216.
doi:10.2298/JSC0712201V .

Verbić, Tatjana, Drakulić, Branko J., Zloh, Mire, Pecelj, Jovana R., Popović, Gordana V., Juranić, Ivan O., "An LFER study of the protolytic equililbria of 4-aryl-2,4-dioxolbutanoic acids in aqueous solutions" in Journal of the Serbian Chemical Society, 72, no. 12 (2007):1201-1216,
https://doi.org/10.2298/JSC0712201V . .