Naslov
A new method for spectrophotometric determination of protonation constants

Autori
Babić, Željko ; Đurina, Vedran ; Horvat, Gordan ; Tomišić, Vladislav ; Žinić, Biserka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The 2nd Opatija Meeting on Computational Solutions in the Life Sciences : Book of Abstracts / Babić, Darko ; Došlić, Nađa ; Smith, David ; Tomić, Sanja ; Vlahoviček, Kristian - Zagreb : Institute of Computational Life Sciences (ICLS), 2007, 59-59

ISBN
978-953-6690-69-5

Skup
The 2nd Opatija Meeting on Computational Solutions in the Life Sciences

Mjesto i datum
Opatija, Hrvatska, 04.09.2007. - 09.09.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
protonation constant ; spectrophotometric determination

Sažetak
A new method for the determination of stoichiometric protonation constants by means of spectrophotometric titrations was developed and implemented in the commercial program Mathematica [1]. The method does not include the pH measurements. It was validated on the simulated spectra generated using the program Simulant [2] and thereafter used to determine protonation constants of the potassium hydrogen phthalate (KHPh) and 1-(p-toluenesulfonyl)cytosine (TsC) [3] in aqueous solutions. For comparison, the data obtained by simultaneous potentiometric and spectrophotometric titrations were analysed by the commercial program SPECFIT [4, 5]. The agreement between the pK values determined with different computational (and experimental) approaches was satisfactory. The protonation constant of TsC has not been previously determined. The obtained value (lg(K1/dm3 mol-1) = 2.34) is more than two units lower than the value for cytosine (lg(K1/dm3 mol-1) = 4.61) [6]. A detailed explanation of such a significant influence of tosyl group remains the subject of further research.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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