TY  - JOUR
AU  - Dražić, Branka
AU  - Popović, Gordana
AU  - Jelić, Ratomir
AU  - Sladić, Dušan
AU  - Mitić, Dragana
AU  - Anđelković, Katarina
AU  - Tešić, Živoslav
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1296
AB  - Acid-base equilibria of Zn(II) and Fe(III) complexes with N',N'2-bis- [(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (ligand L1) and N',N'2-bis[(1E)- -1-(2-pyridyl)ethylidene]propanedihydrazide (ligand L2), i.e., [Fe(L1)Cl2(H2O)], [Fe(L2)Cl(H2O)]2+, [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+, which expressed cytotoxic activity, were investigated in aqueous media. The equilibrium constants were determined potentiometrically at 25°C at a constant ionic strength of 0.10 mol/dm3 (Na2SO4). The results showed that at pH  lt  8 both the Fe(III) complexes studied here have three, while [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+ have one and two titratable protons, respectively. Based on the obtained values for the equilibrium constants, protonation schemes of the examined complexes are proposed.
AB  - U ovom radu su proučavane kiselinsko-bazne ravnoteže u vodenim rastvorima kompleksa Zn(II) i Fe(III) sa N',N'2-bis[(1E)-1-(2-piridil)etiliden]etandihidrazidom (ligand L1) i N',N'2-bis[(1E)-1-(2-piridil)etiliden]propandihidrazidom (ligand L2), tj. [Fe(L1)Cl2(H2O)], [Fe(L2)Cl(H2O)]2+, [Zn(L1)(H2O)3]+, [Zn(L2)(H2O)2]2+, koji pokazuju citotoksičnu aktivnost. Ravnotežne konstante su određivane potenciometrijski, na temperaturi 25°C i pri konstantnoj jonskoj jačini 0,10 mol/dm3 Na2SO4. Utvrđeno je da u intervalu pH  lt  8 ispitivani Fe(III) kompleksi imaju tri, [Zn(L1)(H2O)3]+ jedan, a [Zn(L2)(H2O)2]2+ dva protona koji mogu da se titrišu. Na osnovu dobijenih vrednosti za konstante, pretpostavljene su i odgovarajuće protonacione sheme.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Acid-base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid
T1  - Kiselinsko-bazne ravnoteže kompleksa Fe(III) i Zn(II) sa kondenzacionim derivatima 2-acetilpiridina i hidrazida oksalne, odnosno malonske kiseline
VL  - 74
IS  - 3
SP  - 269
EP  - 277
DO  - 10.2298/JSC0903269D
ER  - 

@article{
author = "Dražić, Branka and Popović, Gordana and Jelić, Ratomir and Sladić, Dušan and Mitić, Dragana and Anđelković, Katarina and Tešić, Živoslav",
year = "2009",
abstract = "Acid-base equilibria of Zn(II) and Fe(III) complexes with N',N'2-bis- [(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (ligand L1) and N',N'2-bis[(1E)- -1-(2-pyridyl)ethylidene]propanedihydrazide (ligand L2), i.e., [Fe(L1)Cl2(H2O)], [Fe(L2)Cl(H2O)]2+, [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+, which expressed cytotoxic activity, were investigated in aqueous media. The equilibrium constants were determined potentiometrically at 25°C at a constant ionic strength of 0.10 mol/dm3 (Na2SO4). The results showed that at pH  lt  8 both the Fe(III) complexes studied here have three, while [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+ have one and two titratable protons, respectively. Based on the obtained values for the equilibrium constants, protonation schemes of the examined complexes are proposed., U ovom radu su proučavane kiselinsko-bazne ravnoteže u vodenim rastvorima kompleksa Zn(II) i Fe(III) sa N',N'2-bis[(1E)-1-(2-piridil)etiliden]etandihidrazidom (ligand L1) i N',N'2-bis[(1E)-1-(2-piridil)etiliden]propandihidrazidom (ligand L2), tj. [Fe(L1)Cl2(H2O)], [Fe(L2)Cl(H2O)]2+, [Zn(L1)(H2O)3]+, [Zn(L2)(H2O)2]2+, koji pokazuju citotoksičnu aktivnost. Ravnotežne konstante su određivane potenciometrijski, na temperaturi 25°C i pri konstantnoj jonskoj jačini 0,10 mol/dm3 Na2SO4. Utvrđeno je da u intervalu pH  lt  8 ispitivani Fe(III) kompleksi imaju tri, [Zn(L1)(H2O)3]+ jedan, a [Zn(L2)(H2O)2]2+ dva protona koji mogu da se titrišu. Na osnovu dobijenih vrednosti za konstante, pretpostavljene su i odgovarajuće protonacione sheme.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Acid-base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid, Kiselinsko-bazne ravnoteže kompleksa Fe(III) i Zn(II) sa kondenzacionim derivatima 2-acetilpiridina i hidrazida oksalne, odnosno malonske kiseline",
volume = "74",
number = "3",
pages = "269-277",
doi = "10.2298/JSC0903269D"
}

Dražić, B., Popović, G., Jelić, R., Sladić, D., Mitić, D., Anđelković, K.,& Tešić, Ž.. (2009). Acid-base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 74(3), 269-277.
https://doi.org/10.2298/JSC0903269D

Dražić B, Popović G, Jelić R, Sladić D, Mitić D, Anđelković K, Tešić Ž. Acid-base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid. in Journal of the Serbian Chemical Society. 2009;74(3):269-277.
doi:10.2298/JSC0903269D .

Dražić, Branka, Popović, Gordana, Jelić, Ratomir, Sladić, Dušan, Mitić, Dragana, Anđelković, Katarina, Tešić, Živoslav, "Acid-base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid" in Journal of the Serbian Chemical Society, 74, no. 3 (2009):269-277,
https://doi.org/10.2298/JSC0903269D . .

TY  - JOUR
AU  - Odović, Jadranka
AU  - Aleksić, Mirjana
AU  - Stojimirović, Biljana
AU  - Milojković-Opsenica, Dušanka
AU  - Tešić, Živoslav
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1294
AB  - The separation and chromatographic behaviour of five ACE (angiotensin converting enzyme) inhibitors and their four active metabolites were investigated by normal-phase thin-layer chromatography on silica using several mono- and binary non-aqueous solvent systems. The linear relationship between the RM values and the composition of employed mobile phase was obtained. The hydrophobicity parameters 0M R and C0 were determined from the regression data of the plots, analogous to reversed-phase chromatography. The chromatographically obtained hydrophobicity parameters were correlated with the calculated log P values. The current results were correlated with the lipophilicity of the studied ACE inhibitors and their metabolites, previously estimated by reversed-phase chromatography.
AB  - Hromatografsko razdvajanje I ponašanje pet ASE inhibitora (inhibitora angio-tenzin-konvertujućeg enzima) I njihova četiri aktivna metabolita ispitivano je metodom normalno-fazne tankoslojne hromatografije na silika-gelu primenom nekoliko jedno- I dvo-komponentnih nevodenih sistema rastvarača. Dobijena je linearna zavisnost između RM-vrednosti I koncentracije etanola u mobilnoj fazi. Na osnovu odgovarajućih regresionih podataka, po analogiji sa reverzno-faznom hromatografijom, izračunati su parametri lipofilnosti 0M R I C0. Hromatografski dobijeni parametri hidrofobnosti korelisani su sa izračunatim log P vrednostima. Takođe, 0M R -vrednosti dobijene u ovom radu korelisane su sa 0M R -vrednostima dobijenim metodom reverzno-fazne tankoslojne hromatografije.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites
T1  - Normalno-fazna tankoslojna hromatografija nekih ACE inhibitora i njihovih metabolita
VL  - 74
IS  - 6
SP  - 677
EP  - 688
DO  - 10.2298/JSC0906677O
ER  - 

@article{
author = "Odović, Jadranka and Aleksić, Mirjana and Stojimirović, Biljana and Milojković-Opsenica, Dušanka and Tešić, Živoslav",
year = "2009",
abstract = "The separation and chromatographic behaviour of five ACE (angiotensin converting enzyme) inhibitors and their four active metabolites were investigated by normal-phase thin-layer chromatography on silica using several mono- and binary non-aqueous solvent systems. The linear relationship between the RM values and the composition of employed mobile phase was obtained. The hydrophobicity parameters 0M R and C0 were determined from the regression data of the plots, analogous to reversed-phase chromatography. The chromatographically obtained hydrophobicity parameters were correlated with the calculated log P values. The current results were correlated with the lipophilicity of the studied ACE inhibitors and their metabolites, previously estimated by reversed-phase chromatography., Hromatografsko razdvajanje I ponašanje pet ASE inhibitora (inhibitora angio-tenzin-konvertujućeg enzima) I njihova četiri aktivna metabolita ispitivano je metodom normalno-fazne tankoslojne hromatografije na silika-gelu primenom nekoliko jedno- I dvo-komponentnih nevodenih sistema rastvarača. Dobijena je linearna zavisnost između RM-vrednosti I koncentracije etanola u mobilnoj fazi. Na osnovu odgovarajućih regresionih podataka, po analogiji sa reverzno-faznom hromatografijom, izračunati su parametri lipofilnosti 0M R I C0. Hromatografski dobijeni parametri hidrofobnosti korelisani su sa izračunatim log P vrednostima. Takođe, 0M R -vrednosti dobijene u ovom radu korelisane su sa 0M R -vrednostima dobijenim metodom reverzno-fazne tankoslojne hromatografije.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites, Normalno-fazna tankoslojna hromatografija nekih ACE inhibitora i njihovih metabolita",
volume = "74",
number = "6",
pages = "677-688",
doi = "10.2298/JSC0906677O"
}

Odović, J., Aleksić, M., Stojimirović, B., Milojković-Opsenica, D.,& Tešić, Ž.. (2009). Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 74(6), 677-688.
https://doi.org/10.2298/JSC0906677O

Odović J, Aleksić M, Stojimirović B, Milojković-Opsenica D, Tešić Ž. Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites. in Journal of the Serbian Chemical Society. 2009;74(6):677-688.
doi:10.2298/JSC0906677O .

Odović, Jadranka, Aleksić, Mirjana, Stojimirović, Biljana, Milojković-Opsenica, Dušanka, Tešić, Živoslav, "Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites" in Journal of the Serbian Chemical Society, 74, no. 6 (2009):677-688,
https://doi.org/10.2298/JSC0906677O . .

TY  - JOUR
AU  - Tosti, Tomislav
AU  - Rakić, Gordana
AU  - Natić, Maja
AU  - Milojković-Opsenica, Dušanka
AU  - Husinec, Suren
AU  - Savić, Vladimir
AU  - Tešić, Živoslav
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1199
AB  - The chromatographic behavior of three biocidal technical materials, rodenticide active ingredients brodifacoum, bromadiolone, and coumatetralyl, and impurities present in the technical material was investigated by both normal-phase (NP) and reversed-phase (RP) planar chromatography. The research was carried out using thin-layers of silica gel, alumina, cellulose, and C-18 silica. Several solvents on their own or in various combinations and proportions were used for separation. The optimum chromatographic systems for separation of the substances from each other and from their impurities were selected. Under reversed-phase chromatographic (RPC) conditions a linear correlation between R-M values and mobile phase composition was established. From results obtained, the lipophilicity R-M(o) and C-0 were determined. Possible separation mechanisms are discussed on the basis of the established retention behavior.
PB  - Akademiai Kiado Zrt, Budapest
T2  - Journal of Planar Chromatography - Modern TLC
T1  - TLC Retention Behavior of Brodifacoum, Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents
VL  - 22
IS  - 5
SP  - 333
EP  - 343
DO  - 10.1556/JPC.22.2009.5.4
ER  - 

@article{
author = "Tosti, Tomislav and Rakić, Gordana and Natić, Maja and Milojković-Opsenica, Dušanka and Husinec, Suren and Savić, Vladimir and Tešić, Živoslav",
year = "2009",
abstract = "The chromatographic behavior of three biocidal technical materials, rodenticide active ingredients brodifacoum, bromadiolone, and coumatetralyl, and impurities present in the technical material was investigated by both normal-phase (NP) and reversed-phase (RP) planar chromatography. The research was carried out using thin-layers of silica gel, alumina, cellulose, and C-18 silica. Several solvents on their own or in various combinations and proportions were used for separation. The optimum chromatographic systems for separation of the substances from each other and from their impurities were selected. Under reversed-phase chromatographic (RPC) conditions a linear correlation between R-M values and mobile phase composition was established. From results obtained, the lipophilicity R-M(o) and C-0 were determined. Possible separation mechanisms are discussed on the basis of the established retention behavior.",
publisher = "Akademiai Kiado Zrt, Budapest",
journal = "Journal of Planar Chromatography - Modern TLC",
title = "TLC Retention Behavior of Brodifacoum, Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents",
volume = "22",
number = "5",
pages = "333-343",
doi = "10.1556/JPC.22.2009.5.4"
}

Tosti, T., Rakić, G., Natić, M., Milojković-Opsenica, D., Husinec, S., Savić, V.,& Tešić, Ž.. (2009). TLC Retention Behavior of Brodifacoum, Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents. in Journal of Planar Chromatography - Modern TLC
Akademiai Kiado Zrt, Budapest., 22(5), 333-343.
https://doi.org/10.1556/JPC.22.2009.5.4

Tosti T, Rakić G, Natić M, Milojković-Opsenica D, Husinec S, Savić V, Tešić Ž. TLC Retention Behavior of Brodifacoum, Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents. in Journal of Planar Chromatography - Modern TLC. 2009;22(5):333-343.
doi:10.1556/JPC.22.2009.5.4 .

Tosti, Tomislav, Rakić, Gordana, Natić, Maja, Milojković-Opsenica, Dušanka, Husinec, Suren, Savić, Vladimir, Tešić, Živoslav, "TLC Retention Behavior of Brodifacoum, Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents" in Journal of Planar Chromatography - Modern TLC, 22, no. 5 (2009):333-343,
https://doi.org/10.1556/JPC.22.2009.5.4 . .

TY  - JOUR
AU  - Mitić, Dragana
AU  - Milenković, Marina
AU  - Milosavljević, Slobodan
AU  - Gođevac, Dejan
AU  - Miodragović, Zoran M.
AU  - Anđelković, Katarina
AU  - Miodragović, Djenana
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1222
AB  - In this paper the first complexes of M2+ ions (M2+ = Zn2+, Cd2+ and Co2+) with N-benzyloxycarbonyl-S-phenylalaninato ligand (1-3) are described. The new complexes were characterized by means of elemental analysis, IR and UV-vis spectroscopy, molar conductivity measurements and H-1, C-13 and N-15 NMR spectroscopy (1D and 2D). The Co(II) complex adopts an octahedral geometry, and the Zn(II) and Cd(II) complexes adopt a tetrahedral one. For the first time, the antimicrobial activity of N-benzyloxycarbonyl-S-phenylalaninato ligand (N-Boc-S-phe) and the complexes 1-3 was investigated against Gram-positive: Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Bacillus subtilis and Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and two strains of the yeast Candida albicans. It was shown that the complexes were effective against most strains. The best activity was detected against the yeast C. albicans.
PB  - Elsevier France-Editions Scientifiques Medicales Elsevier, Issy-Les-Moulineaux
T2  - European Journal of Medicinal Chemistry
T1  - Synthesis, characterization and antimicrobial activity of Co(II), Zn(II) and Cd(II) complexes with N-benzyloxycarbonyl-S-phenylalanine
VL  - 44
IS  - 4
SP  - 1537
EP  - 1544
DO  - 10.1016/j.ejmech.2008.07.017
ER  - 

@article{
author = "Mitić, Dragana and Milenković, Marina and Milosavljević, Slobodan and Gođevac, Dejan and Miodragović, Zoran M. and Anđelković, Katarina and Miodragović, Djenana",
year = "2009",
abstract = "In this paper the first complexes of M2+ ions (M2+ = Zn2+, Cd2+ and Co2+) with N-benzyloxycarbonyl-S-phenylalaninato ligand (1-3) are described. The new complexes were characterized by means of elemental analysis, IR and UV-vis spectroscopy, molar conductivity measurements and H-1, C-13 and N-15 NMR spectroscopy (1D and 2D). The Co(II) complex adopts an octahedral geometry, and the Zn(II) and Cd(II) complexes adopt a tetrahedral one. For the first time, the antimicrobial activity of N-benzyloxycarbonyl-S-phenylalaninato ligand (N-Boc-S-phe) and the complexes 1-3 was investigated against Gram-positive: Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Bacillus subtilis and Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and two strains of the yeast Candida albicans. It was shown that the complexes were effective against most strains. The best activity was detected against the yeast C. albicans.",
publisher = "Elsevier France-Editions Scientifiques Medicales Elsevier, Issy-Les-Moulineaux",
journal = "European Journal of Medicinal Chemistry",
title = "Synthesis, characterization and antimicrobial activity of Co(II), Zn(II) and Cd(II) complexes with N-benzyloxycarbonyl-S-phenylalanine",
volume = "44",
number = "4",
pages = "1537-1544",
doi = "10.1016/j.ejmech.2008.07.017"
}

Mitić, D., Milenković, M., Milosavljević, S., Gođevac, D., Miodragović, Z. M., Anđelković, K.,& Miodragović, D.. (2009). Synthesis, characterization and antimicrobial activity of Co(II), Zn(II) and Cd(II) complexes with N-benzyloxycarbonyl-S-phenylalanine. in European Journal of Medicinal Chemistry
Elsevier France-Editions Scientifiques Medicales Elsevier, Issy-Les-Moulineaux., 44(4), 1537-1544.
https://doi.org/10.1016/j.ejmech.2008.07.017

Mitić D, Milenković M, Milosavljević S, Gođevac D, Miodragović ZM, Anđelković K, Miodragović D. Synthesis, characterization and antimicrobial activity of Co(II), Zn(II) and Cd(II) complexes with N-benzyloxycarbonyl-S-phenylalanine. in European Journal of Medicinal Chemistry. 2009;44(4):1537-1544.
doi:10.1016/j.ejmech.2008.07.017 .

Mitić, Dragana, Milenković, Marina, Milosavljević, Slobodan, Gođevac, Dejan, Miodragović, Zoran M., Anđelković, Katarina, Miodragović, Djenana, "Synthesis, characterization and antimicrobial activity of Co(II), Zn(II) and Cd(II) complexes with N-benzyloxycarbonyl-S-phenylalanine" in European Journal of Medicinal Chemistry, 44, no. 4 (2009):1537-1544,
https://doi.org/10.1016/j.ejmech.2008.07.017 . .

TY  - JOUR
AU  - Verbić, Tatjana Ž.
AU  - Drakulić, Branko
AU  - Zloh, Mire
AU  - Pecelj, Jovana R.
AU  - Popović, Gordana
AU  - Juranić, Ivan O.
PY  - 2007
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/997
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 °C and an ionic strength of 0.1 mol l-1 (NaCl), with the exception of the 4-OH-derivative which was also potentiometrically studied in the pH range 7-10 at 25±1 °C and an ionic strength of 0.1 mol l-1 (NaCl). In solution, the compounds simultaneously exist in one diketo and two enolic forms; therefore, the determined acidity constants (pKa1 1.87-2.29, pKa2 6.63-8.13 and pKa3(4-OH-) 9.52) represent system macro constants. The 1H-NMR spectrum of the parent compound (4-phenyl- -2,4-dioxobutanoic acid) (25 °C, pD 5.0) proved the existence of all tautomeric forms. Using the extended Hammett relation, the determined pKa values were correlated with literature σ values. The predicted pKa 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 LFER 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  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - An LFER study of the protolytic equilibria of 4-aryl-2,4-dioxobutanoic 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 Ž. and Drakulić, Branko and Zloh, Mire and Pecelj, Jovana R. and Popović, Gordana 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 °C and an ionic strength of 0.1 mol l-1 (NaCl), with the exception of the 4-OH-derivative which was also potentiometrically studied in the pH range 7-10 at 25±1 °C and an ionic strength of 0.1 mol l-1 (NaCl). In solution, the compounds simultaneously exist in one diketo and two enolic forms; therefore, the determined acidity constants (pKa1 1.87-2.29, pKa2 6.63-8.13 and pKa3(4-OH-) 9.52) represent system macro constants. The 1H-NMR spectrum of the parent compound (4-phenyl- -2,4-dioxobutanoic acid) (25 °C, pD 5.0) proved the existence of all tautomeric forms. Using the extended Hammett relation, the determined pKa values were correlated with literature σ values. The predicted pKa 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 LFER 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 = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "An LFER study of the protolytic equilibria of 4-aryl-2,4-dioxobutanoic 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. Ž., Drakulić, B., Zloh, M., Pecelj, J. R., Popović, G.,& Juranić, I. O.. (2007). An LFER study of the protolytic equilibria of 4-aryl-2,4-dioxobutanoic acids in aqueous solutions. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 72(12), 1201-1216.
https://doi.org/10.2298/JSC0712201V

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

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