Multiple Dissociation Constants of the Intepirdine Hydrochloride Using Regression of Multiwavelength Spectrophotometric pH-Titration Data

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F18%3A39913009" target="_blank" >RIV/00216275:25310/18:39913009 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1016/j.molliq.2018.04.056" target="_blank" >http://dx.doi.org/10.1016/j.molliq.2018.04.056</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.molliq.2018.04.056" target="_blank" >10.1016/j.molliq.2018.04.056</a>

Result language

angličtina

Original language name

Multiple Dissociation Constants of the Intepirdine Hydrochloride Using Regression of Multiwavelength Spectrophotometric pH-Titration Data

Original language description

Spectrophotometric and potentiometric pH-titrations of the Neurotransmitter Intepirdine hydrochloride INN·HCl for three dissociation constants determination were compared. A nonlinear regression of the pH-spectra (REACTLAB, SQUAD84) and of the pH-titration curve (ESAB) determined three multiple dissociation constants. A sparingly soluble neutral molecule LH of INN·HCl was capable of protonation to form the still soluble three cations LH2+, LH32+ and LH43+ in pure water. Although the change of pH somewhat less affected changes in the chromophore, three consecutive thermodynamic dissociation constants were estimated pKTa1 = 5.64, pKTa2= 7.31, pKTa3=8.85 at 25 °C and pKTa1= 5.51, pKTa2 = 7.15, pKTa3= 8.77 at 37 °C. The graph of molar absorption coefficients of variously protonated species according to wavelength shows that the spectrum of species LH2+ and LH vary in colour, while protonation of chromophore LH2+ to LH32+ and LH43+ has less influence on chromophores in Intepirdine hydrochloride molecule. As the spectral response on the chromophore in the INN·HCl molecule is not large, it was necessary to test a reliability whether it is possible to estimate the dissociation constants even fromsuch small spectrum changes. Three multiple thermodynamic dissociation constants of 3×10−4M INN·HCl were determined by the regression analysis of potentiometric titration curves pKTa1=5.14, pKTa2=8.38, pKTa3=9.33 at25 °C and pKTa1=5.17, pKTa2=8.31, pKTa3=9.07 at 37 °C. The macro-dissociation constants of INN·HCl were estimated according to the chemical structure analyzed by two pKa predictors, the MARVIN and ACD/Percepta programs. The resulting protonation scheme of INN·HCl was suggested.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10406 - Analytical chemistry

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Molecular Liquids

ISSN

0167-7322

e-ISSN

—

Volume of the periodical

261

Issue of the periodical within the volume

July

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

12

Pages from-to

480-491

UT code for WoS article

000436222000050

EID of the result in the Scopus database

2-s2.0-85045688562